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1. (1.3.1.1-6) The process of scavenging a two-stroke cycle diesel engine serves to.
Answer A: improve fuel flow volume
Correct Answer B: cool the exhaust valves
Answer C: reduce the intake air charge density
Answer D: increase the temperature of exhaust gases
2. (1.3.1.1-7) Why will a turbocharged diesel engine produce black smoke if excessive additional load is applied too quickly?
Answer A: Exhaust energy would draw excess air.
Correct Answer B: The inertia of the turbocharger rotor causes a time lag which delays the turbocharger speed increase.
Answer C: Exhaust gas pumping losses are increased due to turbine windage.
Answer D: Exhaust gas back pressure falls slightly due to increased nozzle action.
 
3. (1.3.1.1-3) Which of the listed types of superchargers will NOT have a volumetric capacity proportional to engine speed?
Correct Answer A: Exhaust gas turbocharger
Answer B: Roots blower
Answer C: Piston type blower
Answer D: Vane type blower
4. (1.3.1.1-1) The process of supplying a diesel engine cylinder with air at a pressure greater than atmospheric is called.
Answer A: engine displacement
Answer B: super-aspirating
Answer C: air injection
Correct Answer D: supercharging
5. (1.3.1.1-4) The relative air pressure in the inlet manifold of a turbocharged diesel engine is usually
Correct Answer A: greater than the average exhaust manifold pressure
Answer B: less than the average exhaust manifold pressure
Answer C: greater at the turbine wheel than at the impeller
Answer D: greater at reduced engine speed
 
6. (1.3.1.1-9) According to the illustrated main engine cooling water systems drawing, which of the labeled heat exchangers represents the charge air coolers? Illustration MO-0111
Answer A: 3 and 4
Answer B: 4 and 5
Answer C: 4 and 6
Correct Answer D: 5 and 6
 
7. (1.3.1.1-5) Aftercooling of a turbocharged diesel engine will result in.
Answer A: higher torque but lower brake horsepower
Answer B: lower torque but higher brake horsepower
Correct Answer C: higher torque and higher brake horsepower
Answer D: lower torque and lower brake horsepower
 
8. (1.3.1.1-2) Forcing the exhaust gases from the cylinder of an operating two-cycle diesel engine with the aid of a blower is known as.
Correct Answer A: scavenging
Answer B: forced draft
Answer C: turbocharging
Answer D: aspiration
 
9. (1.3.4.5-3) When a slow-speed diesel engine is used to directly drive a fixed-pitch propeller, how is a stop order met?
Answer A: Both the ahead and astern clutches must be disengaged.
Answer B: The propulsion clutch must be disengaged.
Correct Answer C: The engine itself must be stopped.
Answer D: The propeller must be brought to zero pitch.
10. (1.3.4.5-2) With a direct drive main propulsion arrangement, what statement is true?
Answer A: The engine to propeller shaft speed ratio is variable.
Answer B: The engine speed is greater than the propeller shaft speed.
Correct Answer C: The engine speed is equal to the propeller shaft speed.
Answer D: The engine speed is lower than the propeller shaft speed.
11. (1.3.1.2-6) What statement is true concerning the charge air system of a modern turbocharged slow- speed two-stroke cycle diesel engine?
Answer A: A mechanically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at low engine speeds and loads.
Correct Answer B: An electrically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at low engine speeds and loads.
Answer C: An electrically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at high engine speeds and loads.
Answer D: A mechanically driven auxiliary blower is usually provided because the turbocharger cannot provide enough air at high engine speeds and loads.
 
12. (1.3.1.2-3) The device shown in the illustration is commonly used to. Illustration MO- 0080
Correct Answer A: utilize the flow of exhaust gases to supercharge the engine
Answer B: protect the crankcase from overpressure in event of explosion
Answer C: provide cooling water circulation through the engine
Answer D: provide air starting pressure
 
13. (1.3.11.2-2) How is the illustrated strainer element cleaned during engine operation? Illustration MO- 0057
Correct Answer A: The T-handle is rotated.
Answer B: The housing is removed and the element is cleaned with a solvent.
Answer C: The drain plug is removed and the housing is drained.
Answer D: The strainer element is removed, cleaned in kerosene or solvent, and dried with an air brush.
 
14. (1.3.11.2-9) A dirty lube oil strainer can result in.
Answer A: crankcase dilution
Answer B: low lube oil temperature
Correct Answer C: low bearing oil pressure
Answer D: excessive oil consumption
 
15. (1.3.11.2-6) A dirty diesel engine oil filter element can best be detected by.
Answer A: visual inspection of the elements
Answer B: high lube oil sump temperature
Answer C: decrease in oil viscosity from the filter
Correct Answer D: the pressure drop across the filter
16. (1.3.11.2-15) Scale and dirt accumulation in the waterside of a lube oil cooler will be indicated by a gradual increase in the lube oil.
Answer A: foaming
Answer B: viscosity
Answer C: TBN number
Correct Answer D: temperature
17. (1.3.11.2-3) In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the.
Answer A: air when no air cleaners are used
Correct Answer B: combustion by-products removed from the cylinder walls
Answer C: condensation of water vapors
Answer D: metal particles loosened by wear
 
18. (1.3.10.3-3) The tube sheets installed in a fire-tube auxiliary boiler are normally connected by
Answer A: girder stays
Correct Answer B: fire-tubes and stay-tubes
Answer C: external boiler plating
Answer D: separate crown sheets
19. (1.3.10.3-1) Which of the following statements concerning fire-tube boilers is correct?
Correct Answer A: Combustion gases flow through the tubes.
Answer B: Flames impinge on the tubes.
Answer C: Combustion occurs in the tubes.
Answer D: Water flows through the tubes.
20. (1.3.10.3-4) Fusible plugs are installed in fire-tube boilers to.
Answer A: provide a means of draining the boiler
Correct Answer B: warn the engineer of low water level
Answer C: cool the crown sheet at high firing rates
Answer D: open the burners' electrical firing circuits
 
21. (1.3.1.4-9) As it applies to the combustion process associated with diesel engines, what is meant by the term "scavenging"?
Answer A: Scavenging is the process of filling the cylinder with a charge of fresh air ready for compression.
Answer B: Scavenging is the process of filling the cylinder with a charge of fresh air at pressures above atmospheric pressure.
Answer C: Scavenging is the process of filling the cylinder with a charge of fresh air at atmospheric pressure.
Correct Answer D: Scavenging is the process of removing exhaust gases from the cylinder by blowing in fresh air.
 
22. (1.3.1.4-5) If a slow-speed two-stroke cycle diesel engine is fitted with exhaust valves located in the cylinder heads, what scavenging flow-pattern is utilized?
Answer A: Cross-flow scavenging
Answer B: Return-flow scavenging
Correct Answer C: Uniflow scavenging
Answer D: Loop scavenging
 
23. (1.3.1.4-7) If a slow-speed two-stroke cycle diesel engine is fitted with scavenging air ports and exhaust ports located on opposite sides of the cylinder wall, what scavenging flow-pattern is utilized?
Correct Answer A: Cross-flow scavenging
Answer B: Uniflow scavenging
Answer C: Return-flow scavenging
Answer D: Loop scavenging
24. (1.3.1.4 -2) The power consumed during the scavenging process of a diesel engine is known as the
Answer A: compression loss
Answer B: valve loss
Answer C: back pressure loss
Correct Answer D: pumping loss
 
25. (1.3.1.4-1) During the valve overlap period, the exhaust pressure of a turbocharged, four-stroke cycle diesel engine must be less than the intake manifold pressure to ensure.
Correct Answer A: effective cylinder scavenging and cooling
Answer B: constant pressure from the turbochargers
Answer C: cooler operation of the exhaust system
Answer D: effective constant pressure for turbocharger operation
26. (1.3.8.1 -4) Where is the air charge for an air starting system stored?
Answer A: Air compressor
Correct Answer B: Pressurized tank
Answer C: Distributor assembly
Answer D: Cylinder check valve
 
27. (1.3.8.1-5) An accumulator used in a hydraulic starting system is generally located between the
Answer A: pump and the compressor
Answer B: storage tank and the pump
Answer C: starting motor and the reserve tank
Correct Answer D: pump and the starting motor
 
28. (1.3.8.1 -1) Which of the routine maintenance procedures listed is required for starting air receivers?
Correct Answer A: Frequent draining of accumulated moisture.
Answer B: Frequent testing of relief valves.
Answer C: A close watch on temperature to prevent fluctuations in pressure.
Answer D: Frequent cleaning to remove oil and foreign matter.
 
29. (1.3.8.1-3) A two-stroke cycle diesel engine requires less starting air than a four-stroke cycle diesel engine, of equal displacement, because the two-stroke cycle diesel engine.
Answer A: has little or no internal friction
Answer B: has a lower effective compression ratio
Answer C: operates with scavenge air under a positive pressure
Correct Answer D: operates without energy absorbing intake and exhaust strokes
 
30. (1.3.11.1-2) If the raw water supply pressure for a diesel engine cooling system is below normal, you should check for a.
Answer A: cracked head
Correct Answer B: clogged sea strainer
Answer C: broken thermostat
Answer D: blown head gasket
 
31. (1.3.11.1-4) In a closed cooling water system, which of the following problems can cause the water pressure to fluctuate?
Answer A: An open vent in the cooling system.
Answer B: A restricted water passage in the engine.
Answer C: A fouled sea chest.
Correct Answer D: Air entrained in the cooling water.
32. (1.3.11.1-3) Antifreeze solutions containing ethylene glycol, should not be mixed with corrosion protection oils, as the resultant mixture.
Answer A: is dangerously flammable
Correct Answer B: may cause frothing
Answer C: has a higher chloride content
Answer D: promotes scale buildup
 
33. (1.3.11.1-1) If the cooling water temperature and the lube oil temperature in a diesel engine are too high, the cause can be.
Answer A: a dirty lube oil strainer
Correct Answer B: excessive wear of the cooling water pump
Answer C: an oil suction line restriction
Answer D: internal water leaks
 
34. (1.3.11.3-1) In an operating diesel engine, pre-ignition can be caused by.
Answer A: excessively late fuel injection
Correct Answer B: oil in the air charge
Answer C: water in the fuel
Answer D: injection continuing after the fuel charge is ignited
35. (1.3.11.3-2) Irregular engine speed in a diesel-generator can be caused by.
Answer A: high generator load
Answer B: low fuel viscosity
Answer C: high injection pressure
Correct Answer D: binding in the fuel control linkage
 
36. (1.3.11.3-3) If fuel oil were being discharged from the waste water outlet of a fuel oil disk type centrifuge, operated as a separator, you should.
Answer A: remove the discharge ring
Correct Answer B: reprime the purifier with sealing water
Answer C: slow the centrifuge to its proper speed
Answer D: install an additional discharge ring
37. (1.3.11.3-5) Heat damage to fuel injection nozzles can be prevented by avoiding
Answer A: excess ive fuel oil temperature
Correct Answer B: long periods of engine overload
Answer C: metallic contact between nozzles and cylinder heads
Answer D: hard carbon deposit and varnish on the nozzles
 
38. (1.3.11.3-4) A modern centrifuge, similar to the device shown in the illustration, is opened for periodic cleaning. The most common cause of operating failure after reassembling is due to . Illustration MO-0012
Answer A: low drive motor RPM
Answer B: excessive back pressure in the bowl and fuel oil break over
Answer C: the failure of the opening and closing water supply
Correct Answer D: not replacing the bowl O-rings that have taken a permanent set
39. (1.3.11.3-6) One cause of diesel engine surging can be a result of.
Correct Answer A: injection pump fuel rack binding or sticking
Answer B: low compression
Answer C: solenoid stuck open
Answer D: fuel booster pump pressure too high
 
40. (1.3.10.2-2) The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust.
Answer A: gas composition
Correct Answer B: gas temperature
Answer C: pressure
Answer D: timing
41. (1.3.10.2-1) An exhaust gas bypass is installed on a waste heat boiler in order to.
Answer A: bypass exhaust gas at high loads to prevent excessive back pressure
Answer B: bypass a portion of the exhaust gas at peak loads for better efficiency
Answer C: recycle exhaust gas to the turbocharger
Correct Answer D: minimize moisture condensation in the boiler gas passages at low loads
42. (1.3 .10.2-3) Casing drains may be required on a waste heat boiler gas passage to.
Answer A: prevent an accumulation of boiler water entering gas passages as a result of a pinhole tube leak
Answer B: provide a means to sample stack gases for testing purposes
Answer C: release excess pressure
Correct Answer D: drain off condensation
43. (1.3.10.1-5) The purpose of try-cocks used on an auxiliary boiler is to.
Correct Answer A: provide an alternate means of determining the water level, if the gage glass fails
Answer B: provide a means of adding chemical feed to the boiler water
Answer C: provide a means for blowing down the gage glass
Answer D: act as a steam sentinel valve, if any of the fusible plugs should melt
 
44. (1.3.10.1-3) Which of the following statements concerning fire-tube boilers is correct?
Correct Answer A: Combustion gases flow through the tubes.
Answer B: Flames impinge on the tubes.
Answer C: Combustion occurs in the tubes.
Answer D: Water flows through the tubes.
 
45. (1.3 .10.1-2) In a coil-type forced circulation auxiliary water-tube boiler,.
Correct Answer A: steam demand response is comparatively rapid
Answer B: steam is recirculated through heating coils in the boiler
Answer C: unevaporated feedwater is discharged through the skim tube
Answer D: steam demand response is slow
 
46. (1.3.10.1-4) Bottom blow valves are installed on auxiliary water-tube boilers to.
Answer A: completely drain the boiler in an emergency
Answer B: prevent sludge from forming in the steam drum
Answer C: remove floating impurities from the boiler water surface
Correct Answer D: remove settled solids from the water drum
47. (1.3.6.1 -2) A large, low-speed, main propulsion diesel engine uses sea water to directly cool the
Answer A: cylinder heads
Answer B: exhaust valves
Correct Answer C: scavenging air
Answer D: injectors
 
48. (1.3.6.1-1) Cooling the intake air supplied to a diesel engine will.
Answer A: reduce mean effective pressure
Answer B: decrease average compression ratio
Answer C: decrease air charge density
Correct Answer D: increase peak power output
49. (1.3.6.1-5) What is the function of the intake system for a diesel engine?
Answer A: The intake system's function is to ensure an adequate supply of clean lubricating oil to support engine lubrication.
Answer B: The intake system's function is to ensure an adequate supply of clean sea water to support engine cooling.
Correct Answer C: The intake system's function is to ensure an adequate supply of clean air to support engine combustion and scavenging.
Answer D: The intake system's function is to ensure an adequate supply of clean air to support engine crankcase ventilation.
 
50. (1.3.6.1-3) An increase in the air inlet manifold pressure of a diesel engine will result in a/an
Answer A: decrease in maximum cylinder pressure
Answer B: increase in ignition lag
Correct Answer C: decrease in fuel consumption per horsepower-hour
Answer D: decrease in exhaust manifold pressure
51. (1.3.6.1-4) In a naturally aspirated diesel engine, the volume of air intake is directly associated with engine.
Answer A: compression ratio
Correct Answer B: displacement
Answer C: fuel pressure
Answer D: cylinder clearance volume
52. (1.3.8.3-1) Air motors used for starting some auxiliary diesel engines are generally the type known as.
Correct Answer A: vane motors
Answer B: accumulator motors
Answer C: plunger motors
Answer D: gear motors
 
53. (1.3.8.3-3) When an engine fitted with a hydraulic starting system starts up, the starter is protected from the higher speed of the engine by.
Answer A: the immediate increase in hydraulic pressure
Correct Answer B: the overrunning clutch
Answer C: closing the starting check valves
Answer D: the pivoting of the shaft from being engaged with the flywheel
 
54. (1.3.8.3 -2) Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because.
Answer A: hydraulic starters are the least expensive of all starting systems
Answer B: the system does not require high-pressure piping
Answer C: hydraulic systems turn diesel engines at higher rates of speed than air starters
Correct Answer D: the system can be manually recharged
 
55. (1.3.8.3 -7) Auxiliary diesel engine electric starting motors use.
Answer A: low amperage, high voltage AC power
Answer B: alternating current transformers
Answer C: 400 cycle per second motor-generator power
Correct Answer D: battery power direct current
56. (1.3.8.3-6) The pinion of an auxiliary diesel-electric starting motor normally engages the flywheel ring gear by means of a/an.
Answer A: magnetic type coupling
Answer B: automatic follow-up
Answer C: muff coupling and release
Correct Answer D: Bendix drive or similar mechanism
 
57. (1.3.8.3-4) The purpose of the engine-driven hydraulic pump in an auxiliary diesel engine hydraulic starting system is to.
Correct Answer A: restore hydraulic pressure in the accumulator after starting
Answer B: engage the starter motor with the flywheel
Answer C: fill the sump and prevent low level in the system
Answer D: bypass the hydraulic motor when the engine is running
58. (1.3.8.4-4) In a medium-speed marine propulsion engine equipped with direct admission air starting valves, the cylinders without air starting valves fire first because the.
Answer A: operation is under higher compression
Answer B: fuel is admitted only to these cylinders during cranking
Answer C: compression is released during starting by opening the exhaust valve
Correct Answer D: cylinders are not chilled by the expansion of the starting air
 
59. (1.3.8.4-1) Starting systems for large, direct reversing, main propulsion diesel engines are usually
Answer A: hydraulic starting motors
Answer B: electric starting motors
Correct Answer C: direct air admissions
Answer D: vane type air motors
60. (1.3.8.4-2) During the starting of a diesel engine, compression gases are prevented from backing into the air starting system, shown in the illustration, by the. Illustration MO-0046
Correct Answer A: cylinder air starting check valves
Answer B: high-pressure in the starting air manifold
Answer C: air starting control valve
Answer D: individual distribution valves
61. (1.3.8.4-3) When an air started, four-stroke cycle diesel engine is being cranked over, the starting air is admitted to each cylinder during the beginning of its.
Answer A: intake stroke
Answer B: compression stroke
Correct Answer C: power stroke
Answer D: exhaust stroke
62. (1.3.11.5-1) When an additional load is applied to a diesel engine which is using an inadequately inflated air bladder clutch unit, you can expect.
Answer A: pneumatic seizure
Correct Answer B: overheating because of slipping shoes
Answer C: chipped reduction gear teeth
Answer D: excessive wear on the thrust bearings
63. (1.3.11.5-2) Misalignment of the drive shaft and propeller shaft flanges can be detected by using a dial indicator or.
Answer A: inside micrometer
Correct Answer B: feeler gage
Answer C: adjustable trammel
Answer D: sighting device
64. (1.3.11.5-3) One of the most common causes of reduction gear failure is gear wear caused by scoring as a result of.
Answer A: surface fatigue of the gears
Correct Answer B: an inadequate lube oil film
Answer C: plastic flow of the gears
Answer D: fretting corrosion from water contamination
 
65. (1.3.3.2-1) Which of the following is an example of a solid bearing?
Answer A: Turbo-generator turbine bearing
Answer B: Thrust bearing
Correct Answer C: Piston pin bushing
Answer D: Spring bearing
66. (1.3.3.2-5) Connecting rods in a diesel engine are used to connect the
Answer A: crankshaft to the gear train
Answer B: rocker arm to the camshaft
Answer C: engine to the bed
Correct Answer D: piston to the crankshaft
 
67. (1.3.3.2-9) The diesel engine wrist pin in the illustration is indicated by the component labeled . Illustration MO-0122
Correct Answer A: "7"
Answer B: "17"
Answer C: "G"
Answer D: "S"
 
68. (1.3.3.2-4) The linear motion of a diesel engine piston is converted into the rotary motion required to drive gears, propeller shafts, and generators by the.
Answer A: journal bearings
Answer B: camshaft
Correct Answer C: crankshaft
Answer D: flywheel
 
69. (1.3.3.2-2) The proper location for journal bearing oil grooves is.
Answer A: halfway between bottom and where shells meet
Answer B: at the bottom of the bearing
Correct Answer C: as a side relief where the two shells meet
Answer D: in the region of the load bearing surface
 
70. (1.3.2.4 -1) A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water.
Answer A: overboard
Correct Answer B: around the cooler
Answer C: to the expansion tank
Answer D: around the engine
 
71. (1.3.2.4 -5) The temperature at which an adjustable bellows type thermostatic valve operates is determined by.
Answer A: changing the position of the actuating bulb
Answer B: varying air loading pressure to the bellows
Answer C: replacing the bellows with a heavier spring
Correct Answer D: changing the spring compression opposing the bellows
 
72. (1.3.2.4-4) In a diesel engine closed fresh water cooling system employing a radiator, proper water temperature can be obtained by.
Answer A: passing cooling water through a space heater
Answer B: passing cooling water through the lube oil cooler
Answer C: piping exhaust gases across the radiator front
Correct Answer D: adjusting the radiator louvers
 
73. (1.3.2.4-2) What would be considered a normal temperature increase between the inlet and outlet jacket cooling water of a medium or high-speed diesel engine operating at normal load?
Answer A: 1 to 5F
Answer B: 5 to 10F
Correct Answer C: 10 to 20F
Answer D: 50 to 100F
 
74. (1.3.2.4 -3) An electric heater built into some smaller diesel engines is used to .
Answer A: increase air inlet temperature
Correct Answer B: increase jacket water temperature for easier starting in cold weather
Answer C: increase compression ratio
Answer D: raise lube oil viscosity for easier starting in cold weather
 
75. (1.3.2.4-6) According to the illustrated diesel engine cooling water systems diagram, what fluid is the low temperature central fresh water thermostat designed to maintain? Illustration MO-0129
Answer A: The low temperature central fresh water return header temperature.
Answer B: The low temperature central fresh water cooler outlet temperature.
Correct Answer C: The low temperature central fresh water supply header temperature.
Answer D: The low temperature central fresh water cooler inlet temperature.
76. (1.3.2.4-7) According to the illustrated diesel engine cooling water systems diagram, what is the functional description of the low temperature central fresh water thermostat? Illustration MO-0129
Answer A: The thermostat is a two-way valve set up to throttle the flow bypassing around the central fresh water cooler.
Answer B: The thermostat is a two-way valve set up to throttle the flow through the central fresh water cooler.
Correct Answer C: The thermostat is a three-way valve set up as a mixer proportioning flow through and around the central fresh water cooler.
Answer D: The thermostat is a three-way valve set up as a diverter proportioning flow through and around the central fresh water cooler.
 
77. (1.3.7.3-2) Which of the following problems could develop due to the accumulation of oil vapors in the crankcase of a diesel engine?
Correct Answer A: Crankcase explosion
Answer B: Poor fuel economy
Answer C: Reduced lubrication
Answer D: Combustion knock
78. (1.3.7.3-1) The purpose of an oil mist detector in a main propulsion diesel engine is to warn of
Correct Answer A: a possible overheated bearing
Answer B: excessive carbon buildup in the lube oil
Answer C: low cylinder oil pressure
Answer D: excessively high crankcase vacuum
79. (1.3.7.3-3) The possibility of a diesel engine crankcase explosion will be increased by operating an engine.
Answer A: with a crankcase vacuum between 1.5" and 2" of water
Correct Answer B: with a leaking crankcase inspection cover gasket
Answer C: equipped with a crankcase exhaust blower which vents to fresh air
Answer D: in cooler sea water temperatures
 
80. (1.3.7.3 -4) If a diesel engine has been stopped because of piston seizure due to severe overheating, the crankcase.
Correct Answer A: inspection covers should not be opened until the engine has cooled
Answer B: scavenge pump should be immediately secured to prevent loss of lube oil
Answer C: ventilation system should be continued in operation for one hour for cooling
Answer D: explosion covers should be opened slightly to provide extra ventilation
81. (1.3.2.1 -2) Ethylene glycol, when used as a coolant in a closed cooling system for a diesel engine, is more advantageous than untreated raw water because it .
Answer A: has a higher freezing point and a lower boiling point
Correct Answer B: has a lower freezing point and higher boiling point
Answer C: provides a constant pH below 7
Answer D: provides better vapor-phase cooling
82. (1.3.2.1-7) According to the illustrated main engine cooling water systems diagram, which of the following heat exchangers would be isolated and bypassed while maneuvering in or out of port? Illustration MO-0111
Answer A: 3 and 4
Answer B: 4 and 5
Answer C: 5 and 6
Correct Answer D: 23 and 24
83. (1.3.2.1-6) According to the illustrated main engine cooling water systems diagram, which of the following labeled heat exchangers represents the main lube oil cooler? Illustration MO-0111
Answer A: 3
Correct Answer B: 4
Answer C: 5
Answer D: 6
84. (1.3.2.1-4) According to the illustrated main engine cooling water systems drawing, which labeled heat exchangers use sea water as a cooling medium? Illustration MO-0111
Answer A: 3, 4, 5, 6, and 23
Correct Answer B: 3, 4, 5, 6, and 24
Answer C: 4, 5, 6, and 23
Answer D: 4, 5, 6, and 24
 
85. (1.3.2.1-3) According to the illustrated main engine cooling water systems drawing, which labeled pump is the main engine sea water cooling water pump? Illustration MO-0111
Answer A: 7
Correct Answer B: 8
Answer C: 15
Answer D: 20
86. (1.3.2.1-1) Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to
Answer A: reduce the cooling water temperature
Answer B: increase cooling water hardness
Correct Answer C: form a protective film on metal surfaces
Answer D: maintain low pH in the cooling water
 
87. (1.3.2.1-5) According to the illustrated main engine cooling water systems drawing, which labeled sea water-cooled heat exchanger would have the highest sea water inlet temperature? Illustration MO-0111
Correct Answer A: 3
Answer B: 4
Answer C: 5
Answer D: 6
 
88. (1.3.4.6-1) What type of propeller thrust reversing method (or methods) is or are used with a main propulsion slow-speed crosshead type diesel engine installation?
Answer A: A non-reversing engine driving a fixed-pitch propeller is the only method used.
Answer B: A reversing engine driving a controllable-pitch propeller is the only method used.
Correct Answer C: Either a reversible engine driving a fixed-pitch propeller or a non-reversible engine driving a controllable-pitch propeller could be used.
Answer D: Either a reversible engine driving a controllable-pitch propeller or a non-reversible engine driving a fixed-pitch propeller could be used.
 
89. (1.3.4.6-5) Diesel engines powering large vessels that drive fixed-pitch propellers through a non- reversing reduction gear are of what type?
Answer A: Medium-speed, non-reversing engines
Answer B: Slow-speed, reversing engines
Answer C: Slow-speed, non-reversing engines
Correct Answer D: Medium-speed, reversing engines
 
90. (1.3.7.2-1) Which of the following statements is true concerning a main diesel engine oil cooler?
Correct Answer A: The oil pressure is greater than the cooling water pressure.
Answer B: The oil flow control valve is always installed in the oil input line.
Answer C: The oil temperature is less than the cooling water temperature.
Answer D: The oil pressure is less than the cooling water pressure.
 
91. (1.3.7.2-2) The lube oil cooler is located after the lube oil filter in order for.
Correct Answer A: the filter to operate more efficiently
Answer B: galvanic action in the cooler to be minimized
Answer C: positive lube oil pump suction to be assured
Answer D: the lube oil cooler to be bypassed
 
92. (1.3.4.4-3) What is the function of the main thrust bearing?
Answer A: Prevents lateral movement of the slow-speed gear.
Correct Answer B: Transmits propeller thrust to the hull.
Answer C: Keeps spring bearings in line.
Answer D: Prevents main reduction gear axial movement.
 
93. (1.3.4.4-1) Which of the statements represents a characteristic of the thrust collar in a Kingsbury thrust bearing?
Correct Answer A: It turns with the shaft and the pivot shoes do not rotate.
Answer B: It is stationary and the shoes turn with the shaft.
Answer C: It is turned by the base ring of the bearing.
Answer D: It is held in position by the bearing base ring.
 
94. (1.3.4.3-3) The component shown in the illustration, labeled "I", is the. Illustration SE-0013
Answer A: first reduction pinion
Correct Answer B: first reduction gear
Answer C: second reduction pinion
Answer D: second reduction gear
 
95. (1.3.4.3-7) In addition to achieving a speed reduction for efficient propeller operation, what statement represents other possible functional purposes for reduction gears?
Answer A: Reduction gears can be used for engine rotation reversal and reduction gears can be used for multiple propeller shaft outputs.
Correct Answer B: Reduction gears can be used for propeller thrust reversal and reduction gears can be used for multiple prime mover inputs.
Answer C: Reduction gears can be used for propeller thrust reversal and reduction gears can be used for multiple propeller shaft outputs.
Answer D: Reduction gears can be used for engine rotation reversal and reduction gears can be used for multiple prime mover inputs.
 
96. (1.3.4.3-6) Reduction gear casings are vented in order to.
Answer A: allow windage to exist for cooling the gears
Correct Answer B: avoid a buildup of pressure within the gear case
Answer C: minimize lube oil foaming within the case
Answer D: allow for axial clearance between the gears
 
97. (1.3.4.3-2) The purpose of the main diesel engine reduction gears is to.
Answer A: transmit vibration and thrust to the ship's hull
Answer B: provide a means of reversing the main diesel engines in an emergency
Correct Answer C: reduce high diesel engine RPM to an efficient propeller RPM
Answer D: reduce engine room noise levels during high-speed operations
98. (1.3.4.3-5) What type of reduction gear would most commonly be used with twin medium-speed propulsion diesel engines driving a single shaft?
Answer A: Single reduction, planetary
Answer B: Single reduction, single input
Correct Answer C: Single reduction, double input
Answer D: Double reduction, double input, articulated
 
99. (1.3.4.3-8) What would be the most accurate description of the illustrated cutaway drawing of a reduction gear as used for medium-speed diesel propulsion? Illustration MO-0085
Answer A: Single input, single reduction, non-reversing gear
Answer B: Single input, double reduction, non-reversing gear
Answer C: Single input, double reduction, reversing gear
Correct Answer D: Single input, single reduction, reversing gear
100. (1.3.4.3-1) Which of the following methods is used to lubricate main propulsion medium-speed diesel engine reduction gears?
Correct Answer A: Oil is sprayed through nozzles at the point of gear mesh.
Answer B: Oil rings in channels outside the gears dip into oil in the sump and carry it to the gear teeth.
Answer C: The gears run through an open oil sump and oil is carried along on the gear teeth.
Answer D: Oil is pressure fed through internal drilled passages which force oil to the gear's periphery.
 
101. (1.3.5.3-3) In what location is heavy fuel oil kept above the flash point, but below the boiling point of water?
Answer A: Heavy fuel oil settling and day tanks
Answer B: Heavy fuel oil mixing tank
Correct Answer C: Heavy fuel oil final heater outlet
Answer D: Heavy fuel oil purifier heater outlet
 
102. (1.3.5.3-2) In what location is heavy fuel oil kept below the flash point?
Correct Answer A: Heavy fuel oil settling and day tanks
Answer B: Heavy fuel oil mixing tank
Answer C: Heavy fuel oil purifier heater outlet
Answer D: Heavy fuel oil final heater outlet
 
103. (1.3.5.3-4) In an HFO service system, what is the immediate destination of the fuel unconsumed by the main propulsion diesel engine?
Answer A: The unconsumed fuel is recirculated back to the fuel injection pumps suction.
Answer B: The unconsumed fuel is recirculated back to the settling tank.
Correct Answer C: The unconsumed fuel is recirculated back to the mixing tank (if fitted) or to the day tank.
Answer D: The unconsumed fuel is recirculated back to the booster pump suction.
104. (1.3.6.2-1) What is the function of the aftercoolers installed in the diesel engine air intake system?
Answer A: Decrease the air density
Answer B: Increase the exhaust temperature
Answer C: Decrease the lube oil temperature
Correct Answer D: Increase the air density
105. (1.3.11.4 -3) Which of the following conditions is most likely to occur if the electric starter motor pinion gear fails to disengage from the flywheel of a diesel engine after the engine has started?
Answer A: Engine will stop
Correct Answer B: Starting motor will dangerously overspeed
Answer C: Flywheel will be damaged
Answer D: Combustion gases will enter the air starting system
106. (1.3.11.4-4) When starting air is admitted, a diesel engine turns over very slowly without firing. The cause may be.
Answer A: an obstruction in an engine cylinder
Answer B: water accumulation in some engine cylinders
Correct Answer C: low starting air pressure
Answer D: low scavenge air pressure
107. (1.3.11.4-1) Which of the following problems can occur if you continually fail to drain off condensate from a starting air receiver?
Correct Answer A: Corrosion and eventual failure of the tank.
Answer B: Gumming of the tank relief valves.
Answer C: Immediate failure of components downstream of the compressed air system.
Answer D: Boiling of the water oil mixture as pressure is reduced.
108. (1.3.11.6 -4) Black smoke exhausting from an operating diesel engine is an indication of poor combustion which may be caused by.
Answer A: water in the fuel
Answer B: insufficient fuel for combustion
Correct Answer C: clogged air intake passages
Answer D: burning lubricating oil
 
109. (1.3.11.6-2) A dry-type exhaust silencer clogged with soot, will cause.
Answer A: low exhaust temperature
Correct Answer B: loss of engine power
Answer C: burned intake valves
Answer D: engine racing
110. (1.3.11.6-1) In a diesel engine, a leaking exhaust valve can cause.
Correct Answer A: misfiring
Answer B: pre-ignition
Answer C: interrupted scavenging
Answer D: reduced scavenging
111. (1.3.10.5-2) The solenoid valves in the fuel oil supply line to an automatically fired auxiliary boiler, are automatically closed by.
Answer A: a decrease in feed temperature
Answer B: high furnace air pressure
Correct Answer C: high steam pressure
Answer D: low steam pressure
112. (1.3 .10.5-3) Control of the fuel oil metering valve in an automatically fired auxiliary boiler is accomplished by a.
Answer A: pressure magnifying device in the steam coil outlet
Correct Answer B: steam pressure sensing device with linkage to the damper air vanes
Answer C: metering device in the air supply line
Answer D: signal from the feedwater electrode
113. (1.3.10.5-1) A variable capacity, pressure atomizing, fuel oil burner functions to
Answer A: maintain a constant fuel temperature
Correct Answer B: provide a wide range of combustion
Answer C: provide a constant fuel return pressure
Answer D: maintain smokeless fuel oil atomization
 
114. (1.3.8.2-3) Diesel engine electric starting motors generally require heavier duty motors and operate at higher voltages than comparable starting motors for gasoline engines due to
Answer A: flywheel effect
Correct Answer B: higher compression pressures
Answer C: lower starting temperatures
Answer D: higher speed required
115. (1.3.8.2 -2) Auxiliary diesel engine electric starting motors use .
Correct Answer A: battery power direct current
Answer B: 400 cycle per second motor-generator power
Answer C: alternating current transformers
Answer D: low amperage, high voltage AC power
116. (1.3.3.3-4) When attempting to restart a warm high-speed engine, which of the following reactions can you expect?
Answer A: Excessive fuel use
Answer B: Higher than normal lube oil pressure
Answer C: Longer starting periods
Correct Answer D: Higher than normal temperatures for start up
 
117. (1.3.3.3-1) A normally operating diesel engine is shutdown by.
Answer A: overspeeding the engine
Correct Answer B: securing the fuel supply
Answer C: shutting off the air supply
Answer D: securing the ignition system
118. (1.3.3.3 -2) Before starting a diesel engine, you should always.
Answer A: clean the air filter
Correct Answer B: check the crankcase oil level
Answer C: change the fuel oil strainers
Answer D: check the pyrometer readings
 
119. (1.3.3.3-5) Before starting a diesel engine that has an engine driven lube oil pump, you should
Answer A: top off the expansion tank
Correct Answer B: pressurize the lube oil system with the pre-lube pump
Answer C: open the bypass line
Answer D: cut in the lube oil cooler
 
120. (1.3.3.3-3) Which of the listed diesel engine operating conditions should be checked immediately after any diesel engine is started?
Correct Answer A: Lube oil pressure
Answer B: Exhaust temperature
Answer C: Lube oil level
Answer D: Water level in the expansion tank
121. (1.3.4.1-5) By what means are two sections of propulsion line shafting typically joined together?
Answer A: By the use of a sleeve or clamp type solid coupling
Correct Answer B: By the use of a flange type solid coupling
Answer C: By the use of a chain type flexible coupling
Answer D: By the use of a gear type flexible coupling
 
122. (1.3.4.1-9) What statement is true concerning oil-lubricated stern tube bearings?
Answer A: The forward and after seals are both designed to prevent the ingress of sea water and the after seal is designed to retain the lubricating oil within the bearing.
Answer B: The forward and after seals are both designed to prevent the ingress of sea water and the forward seal is designed to retain the lubricating oil within the bearing.
Answer C: The forward and after seals are both designed to retain the lubricating oil within the bearings and the forward seal is designed to prevent the ingress of sea water.
Correct Answer D: The forward and after seals are both designed to retain the lubricating oil within the bearings and the after seal is designed to prevent the ingress of sea water.
123. (1.3.4.1-8) What is the primary purpose of self-aligning spherically-seated line shaft bearings?
Answer A: To compensate for torsional twisting of the shaft in response to torque variations.
Answer B: To compensate for variations in propeller thrust loading in response to load changes.
Correct Answer C: To compensate for flexing of the hull in response to different loading conditions.
Answer D: To compensate for propeller induced vibrations as a result of propeller irregularities.
 
124. (1.3.4.1-2) Which of the following methods is used to securely fasten the babbitt lining of a reduction gear bearing to its shell?
Answer A: The babbitt has a crescent shaped pocket cast symmetrically about the bearing split.
Correct Answer B: The babbitt is centrifugally spun into the bearings or cast under a pressure head.
Answer C: The babbitt is securely bonded to the shell by the pressure of the hydrodynamic oil wedge.
Answer D: The babbitt is relieved in way of the split and held in place by locking pins.
 
125. (1.3.4.1-7) In addition to checking the lube oil sump level and temperature of a line shaft steady bearing, what else must be checked for?
Answer A: Ensure flow through the gravity head tank overflow sight glass.
Correct Answer B: Ensure free rotation of the oiling ring with the shaft.
Answer C: Ensure that the oiling ring does not rotate with the shaft.
Answer D: Ensure adequate lube oil pump discharge pressure.
 
126. (1.3.4.1-1) Babbitt is a metal alloy commonly used for lining.
Correct Answer A: precision bearings
Answer B: shim stock
Answer C: valve seats
Answer D: salt water piping
127. (1.3.4.1-10) When checking a water-lubricated stern tube bearing while underway, what should be checked for?
Answer A: Ensure that the stuffing box packing gland is loose enough so that the last ring of packing is visible.
Answer B: Ensure that the stuffing box packing gland is tight enough so that there is no leakoff whatsoever.
Correct Answer C: Ensure that the stuffing box packing gland is taken up just enough so that the leakoff rate is a periodic drip.
Answer D: Ensure that the stuffing box packing gland is loose enough so that there is a steady stream of water leaking by.
128. (1.3.10.4-4) The pressuretrol which is installed on an auxiliary boiler senses steam pressure changes and.
Answer A: controls the flow of feedwater to the boiler
Answer B: monitors the boiler high water level
Answer C: secures the fires when a fusible plug burns out
Correct Answer D: automatically regulates the quantity of oil and air flow to the burner
 
129. (1.3.10.4-2) The primary function of a flame safeguard system, as used on an automatically fired auxiliary boiler, is to prevent.
Answer A: accidental dry firing and overpressure
Answer B: uncontrolled fires in the furnace
Correct Answer C: explosions in the boiler furnace
Answer D: overheating of the pressure parts
130. (1.3.10.4-1) Constant capacity, pressure atomizing, fuel burners designed to meet a wide variation in steaming loads on an auxiliary boiler, are.
Answer A: automatically supplied with warmer air on demand
Answer B: automatically supplied with more fuel on demand
Answer C: equipped with standard variable capacity atomizers
Correct Answer D: cycled on and off in response to steam demand
131. (1.3.3.1-11) The most important factor in engine performance is the actual power output at the end of the crankshaft available for doing work. This is known as.
Answer A: indicated horsepower
Correct Answer B: brake horsepower
Answer C: net horsepower
Answer D: friction horsepower
 
132. (1.3.3.1-12) Which of the following relationships exist between the temperature developed in a combustion space, and the compression ratio of the engine?
Correct Answer A: Higher compression ratios create higher temperatures.
Answer B: Higher temperatures create higher compression ratios.
Answer C: Lower temperatures create higher compression ratios.
Answer D: Higher compression ratios create lower temperatures.
 
133. (1.3.3.1-6) The highest pressure in a diesel engine cylinder normally occurs.
Answer A: at TDC
Answer B: before TDC
Correct Answer C: after TDC
Answer D: during air starting
 
134. (1.3.3.1-2) Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?
Answer A: Compression must be low for smooth operation.
Correct Answer B: The heat of compression is not used as an ignition source of the fuel.
Answer C: Compression must be low to have effective pre-ignition.
Answer D: Compression must be low for effective spark ignition.
 
135. (1.3.3.1-3) In the starting process of a diesel engine, the main object is to attain the compression conditions sufficient to.
Answer A: turn the flywheel
Correct Answer B: ignite the fuel
Answer C: reduce friction
Answer D: overcome inertia
 
136. (1.3.3.1-5) Diesel engines are classified as reciprocating internal combustion engines because they.
Answer A: burn fuel in a combustion chamber that moves back and forth
Answer B: use a continuous combustion process to impart rotary motion to the pistons
Correct Answer C: burn fuel in a closed chamber which imparts linear motion to pistons
Answer D: use energy from fuel burned outside their cylinders
137. (1.3.3.1 -8) Which of the terms listed below represents the operational speed at which excessive engine vibration is created?
Answer A: Non-harmonic speed.
Correct Answer B: Critical speed.
Answer C: Maximum speed.
Answer D: Design maximum speed.
 
138. (1.3.11.7-10) Which of the following conditions is indicated by the presence of water in the scavenging air receiver?
Answer A: Leaking cylinder head gaskets
Correct Answer B: Leaking aftercooler
Answer C: Excessively high scavenge air temperature
Answer D: Auxiliary blower failure
139. (1.3.11.7-3) The power output of a turbocharged diesel engine will drop if the cooling water flow through the aftercooler is interrupted because the.
Answer A: turbocharger stalls
Answer B: exhaust pressure increases
Correct Answer C: air charge density decreases
Answer D: scavenge effect increases
140. (1.3.11.7-6) An operating diesel engine that suddenly loses power, is due to a/an.
Correct Answer A: restricted turbocharger air intake
Answer B: oil leak into the turbocharger
Answer C: dribbling injector
Answer D: low fuel viscosity
 
141. (1.3.11.7-8) A sudden power loss from a turbocharged and aftercooled diesel engine is an indication of a/an.
Correct Answer A: turbocharger malfunction or failure
Answer B: crankcase exhauster overload
Answer C: overload on the intercooler
Answer D: obstruction in the engine cylinders
142. (1.3.11.7-2) Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the.
Answer A: air charge density becoming too high
Answer B: piston crown surfaces becoming too cold
Correct Answer C: formation of excessive quantities of condensate
Answer D: compression pressure being greatly reduced
143. (1.3.2.2-3) The highest pressure in any closed diesel engine fresh water cooling system is at the
Answer A: jacket water outlet
Answer B: expansion tank inlet
Correct Answer C: cooling water pump outlet
Answer D: heat exchanger inlet
144. (1.3.2.2-10) According to the illustrated diesel propulsion plant fresh water cooling systems diagram, in which subsystem is the deaerator located? Illustration MO-0072
Correct Answer A: Main engine cylinder jacket cooling water system
Answer B: Main engine fuel injector cooling water system
Answer C: SSDG cylinder jacket cooling water system
Answer D: Main engine piston cooling water system
 
145. (1.3.2.2 -9) According to the illustrated main and auxiliary diesel engine cooling water systems diagram, which of the following heat exchangers are connected directly in series with one another? Illustration MO-0129
Answer A: Camshaft lube oil cooler and jacket water cooler
Answer B: Jacket water cooler and scavenge air coolers(s)
Correct Answer C: Lube oil cooler and jacket water cooler
Answer D: Camshaft lube oil cooler and scavenge air coolers(s)
 
146. (1.3.2.2-6) Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to
Answer A: increase cooling water hardness
Correct Answer B: form a protective film on metal surfaces
Answer C: reduce the cooling water temperature
Answer D: maintain low pH in the cooling water
 
147. (1.3.2.2 -1) Cooling water pumps driven by direct reversing diesel engines are usually
Answer A: curved impeller vane with tangential outlet
Answer B: straight impeller vane with tangential housing
Correct Answer C: straight impeller vane with concentric housing
Answer D: curved impeller vane with concentric outlet
 
148. (1.3.2.2 -5) A closed fresh water cooling system is commonly used with marine diesel engines because the.
Answer A: cooling water temperature differential is greater
Answer B: cooling water pumps are directly reversible
Correct Answer C: jacket water temperature is more easily controlled
Answer D: need for water treatment is eliminated
149. (1.3.2.2-2) The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and.
Answer A: reduce water temperature
Correct Answer B: allow for an increase in water volume as the engine warms up
Answer C: reduce water turbulence
Answer D: provide an air-cushion
 
150. (1.3.5.2 -1) Fuel injection pumps using the port and helix metering principle requires the use of a
Answer A: crosshatched design
Correct Answer B: lapped plunger and barrel
Answer C: variable stroke
Answer D: variable cam lift
151. (1.3.5.2-3) The amount of fuel delivered by a helical plunger fuel injection pump is controlled by
Answer A: varying the pump discharge pressure
Answer B: varying the pump return pressure
Correct Answer C: rotation of the pump plunger
Answer D: rotation of the pump barrel
 
152. (1.3.6.3-2) A naturally aspirated diesel engine at full throttle will have an intake manifold pressure
Correct Answer A: slightly less than atmospheric pressure
Answer B: approximately equal to exhaust manifold pressure at all times
Answer C: that is widely fluctuating
Answer D: constantly decreasing as engine load increases
 
153. (1.3.7.1-3) A magnetic strainer is primarily used in diesel engine reduction gear oil systems to remove small particles of.
Correct Answer A: ferrous materials
Answer B: babbitt
Answer C: copper
Answer D: acidic materials
 
154. (1.3.7.1-1) The lube oil strainer shown in the illustration is used on the reduction gear of a mid- size diesel engine. The strainer elements consist of. Illustration MO-0057
Answer A: fibrous braid
Answer B: wire mesh
Answer C: pleated paper
Correct Answer D: metal disks
 
155. (1.3.7.1-4) Where would a coarse screen wire mesh strainer normally be found on a diesel engine lubrication system?
Correct Answer A: pump suction line
Answer B: filter bypass return line
Answer C: pump discharge line
Answer D: gravity tank inlet line
 
156. (1.3.7.1-2) Lube oil cannot be efficiently filtered if its.
Answer A: pump capacity is greater than the system's needs
Answer B: viscosity is too low
Answer C: pump discharge pressure is higher than the system's pressure
Correct Answer D: temperature is too low
 
157. (1.3.5.5-5) What would be the primary indication that a heavy fuel oil purifier supply pump suction strainer needed cleaning?
Answer A: An increase in fuel oil supply temperature to the bowl.
Correct Answer B: An increased pressure drop across the strainer (more differential).
Answer C: A decreased pressure drop across the strainer (less differential).
Answer D: A drop in purifier bowl speed.
158. (1.3.5.5-6) What would be the primary indication that a fuel oil service system booster pump duplex suction strainer needed to be shifted over and cleaned?
Answer A: A decreased pressure drop across the strainer element on service (less differential).
Correct Answer B: An increased pressure drop across the strainer on service (more differential).
Answer C: A drop in fuel oil service system booster pump rotational speed.
Answer D: An increase in fuel oil service system booster pump discharge pressure.
159. (1.3.5.5-2) To minimize corrosion, fuel oil strainer disks, spacers and scraper blades are made of
Answer A: brass
Answer B: copper
Answer C: iron
Correct Answer D: monel metal or stainless steel
 
160. (1.3.5.5-4) According to the illustrated diesel engine fuel treatment and fuel service systems schematic, what is the purpose of the valve labeled "1"? Illustration MO-0077
Answer A: HFO/DO fuel mixing valve for main engine
Answer B: HFO/DO fuel changeover valve for auxiliary engines (and boiler)
Correct Answer C: HFO/DO fuel changeover valve for main engine
Answer D: HFO/DO fuel mixing valve for auxiliary engines (and boiler)
161. (1.3.5.5-3) For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because.
Correct Answer A: changing filter elements would not interrupt engine operation
Answer B: filtering occurs twice in each pass of oil through the system
Answer C: clogging will not occur
Answer D: dropping pressure is half of that through a single filter unit
162. (1.3.5.5-1) Valve '1', as shown in the illustration, should be operated when. Illustration MO-0077
Correct Answer A: entering or departing port
Answer B: starting auxiliary boilers
Answer C: viscosimeter 'V' measures low viscosity
Answer D: mixing tank is 'full'
163. (1.3.9.1-4) One of the factors limiting the amount of load which can be put on a modern marine diesel engine is the.
Answer A: governor sensitivity
Correct Answer B: exhaust temperature
Answer C: fuel injection pressure
Answer D: speed of the camshaft
164. (1.3.9.1-7) The exhaust system for a turbocharged diesel engine functions to.
Answer A: power the aftercoolers
Correct Answer B: power the turbocharger
Answer C: reduce the cylinder scavenge effect
Answer D: cool the turbocharger
165. (1.3.9.1-3) In a diesel engine exhaust system, the cooling of the exhaust gases below their dew point, will result in.
Answer A: increased engine back pressure
Correct Answer B: sulfuric acid corrosion
Answer C: surface pitting of the turbocharger compressor blades
Answer D: moisture impingement on the turbocharger compressor blading
 
166. (1.3.9.1-2) The most common instrument used to measure diesel engine exhaust pressure is the
Answer A: pyrometer
Answer B: bourdon gauge
Answer C: pneumercator
Correct Answer D: manometer
 
167. (1.3.9.1-5) Exhaust pipes for separate main propulsion diesel engines can be combined only when.
Answer A: space limitations prevent separately run pipes
Answer B: the engines are small auxiliary units
Correct Answer C: they are arranged to prevent gas backflow to each engine
Answer D: a waste heat boiler is installed
 
168. (1.3.5.4-1) Which of the listed substances can be satisfactorily removed from diesel fuel by centrifuging?
Correct Answer A: Sludge
Answer B: Gasoline
Answer C: Fuel oil
Answer D: Lube oil
169. (1.3.5.4-5) When monitoring a heavy fuel oil treatment plant, what would be an indication that the treatment plant throughput volume is less than the main engine consumption?
Answer A: The HFO settling tank will continuously drop in level.
Correct Answer B: The HFO day tank will continuously drop in level.
Answer C: The HFO day tank will rise and eventually overflow into the HFO settling tank.
Answer D: The HFO settling tank will rise and eventually overflow into the HFO day tank.
170. (1.3.5.4 -7) According to the illustrated diesel engine fuel treatment and fuel service systems schematic, what would be the appropriate valve configuration for operating the two heavy fuel oil purifiers in series? Illustration MO-0077
Answer A: Valves 2, 3, and 6 all OPEN
Answer B: Valves 2, 3, and 6 all CLOSED
Answer C: Valves 2 and 3 OPEN, and Valve 6 CLOSED
Correct Answer D: Valves 2 and 3 CLOSED, and Valve 6 OPEN
 
171. (1.3.5.4-2) Whether using a centrifuge or a simple filter, oil cleaning and filtration will be the most effective when the oil is at a.
Answer A: high temperature and a high viscosity
Correct Answer B: high temperature and a low viscosity
Answer C: low temperature and a high viscosity
Answer D: low temperature and a low viscosity
172. (1.3.5.4 -9) According to the illustrated diesel engine fuel treatment and fuel service systems schematic, what statement is true concerning the valves labeled "4" and "5"? Illustration MO-0077
Correct Answer A: Valves 4 and 5 are closed during normal operation, but when opened will allow one of the HFO purifiers to be used as a backup DO purifier, should the DO purifier become disabled.
Answer B: Valves 4 and 5 are closed during normal operation, but when opened will allow the DO purifier to be used as a backup HFO purifier, should one of the HFO purifiers become disabled.
Answer C: Valves 4 and 5 are closed during normal operation, but when opened will allow all three purifiers to centrifuge HFO while in series.
Answer D: Valves 4 and 5 are closed during normal operation, but when opened will allow all three purifiers to centrifuge HFO while in parallel.
173. (1.3.7.4-1) Which of the following methods is normally used to lubricate bearings in a small high- speed diesel engine?
Answer A: Splash lubrication
Correct Answer B: Pressure lubrication
Answer C: Sight feed lubricators
Answer D: Mechanical lubricators
174. (1.3.7.4 -4) Lube oil pumps taking suction from the sump of most small marine engines are usually
Answer A: diaphragm type
Answer B: eductor type
Answer C: centrifugal type
Correct Answer D: positive displacement type
 
175. (1.3.5.1 -6) The main advantage of unit injectors over other fuel injection systems is.
Correct Answer A: the lack of high-pressure fuel lines
Answer B: their relatively low injection pressures
Answer C: reduced wear of spray orifices
Answer D: the lessened chance of fuel leaks into the engine sump
176. (1.3.5.1-5) The illustrated device is operated directly by. Illustration MO-0041
Answer A: a rocker arm and push rod
Correct Answer B: fuel oil pressure
Answer C: cam action
Answer D: excessively high combustion pressure
177. (1.3.5.1-3) Movement of the pump control rack in a fuel injection system using individual plunger- type pumps.
Answer A: varies the compression of the delivery valve spring
Answer B: changes the length of the pump stroke
Answer C: changes the position of the fuel inlet ports
Correct Answer D: varies the quantity of fuel delivered
178. (1.3.5.1-7) Injection pressure in a common rail fuel system is controlled by
Answer A: engine speed
Answer B: varying the fuel pump piston stroke
Answer C: varying the injector needle valve clearance
Correct Answer D: a bypass valve
 
179. (1.3.5.1-4) Fuel oil discharged into the diesel engine cylinder is atomized at the.
Answer A: turbocharger
Correct Answer B: injector nozzle tip
Answer C: carburetor
Answer D: fuel oil pump
 
180. (1.3.2.3 -5) In a diesel engine jacket water cooler, with sea water cooling the engine jacket cooling water, what statement is true?
Correct Answer A: The jacket water pressure is always kept higher than the sea water pressure, and in case of a jacket water cooler leak, the jacket water expansion tank level will increase.
Answer B: The sea water pressure is always kept higher than the jacket water pressure, and in case of a jacket water cooler leak, the jacket water expansion tank level will increase.
Answer C: The jacket water pressure is always kept higher than the sea water pressure, and in case of a jacket water cooler leak, the jacket water expansion tank level will decrease.
Answer D: The sea water pressure is always kept higher than the jacket water pressure, and in case of a jacket water cooler leak, the jacket water expansion tank level will decrease.
 
181. (1.3.2.3-4) In a diesel engine lube oil cooler, with sea water cooling the lubricating oil, what statement is true?
Correct Answer A: The lube oil pressure is always kept higher than the sea water pressure, and in case of a lube oil cooler leak, the lube oil sump level will decrease.
Answer B: The sea water pressure is always kept higher than the lube oil pressure, and in case of a lube oil cooler leak, the lube oil sump level will increase.
Answer C: The sea water pressure is always kept higher than the lube oil pressure, and in case of a lube oil cooler leak, the lube oil sump level will decrease.
Answer D: The lube oil pressure is always kept higher than the sea water pressure, and in case of a lube oil cooler leak, the lube oil sump level will increase.
 
182. (1.3.2.3-1) Sacrificial zinc anodes are used on the salt water side of diesel engine heat exchangers to.
Answer A: keep heat transfer surfaces shiny and clean
Correct Answer B: reduce electrolytic action on heat exchanger metals
Answer C: prevent rapid accumulation of marine growth
Answer D: provide a protective coating on heat exchanger surfaces
183. (1.3.2.3-2) In a diesel engine jacket water cooler, with sea water cooling the fresh water, the
Correct Answer A: jacket water pressure should always be greater than the sea water pressure
Answer B: jacket water pressure must always be less than the sea water pressure
Answer C: jacket water temperature must always be less than 60F
Answer D: sea water temperature must never be warmer than 40F
 
184. (1.3.4.2-1) Which of the devices listed is commonly used to compensate for the expansion and minor misalignments occurring between the main turbine rotor and the reduction gear?
Answer A: Quill shaft
Answer B: Expansion gear
Answer C: Sliding sleeve
Correct Answer D: Gear-type flexible coupling
 
185. (1.3.4.2-6) What type of clutch is used in the illustrated medium-speed diesel engine reduction gear? Illustration MO-0085
Correct Answer A: Pneumatic
Answer B: Mechanical
Answer C: Electromagnetic
Answer D: Hydraulic
186. (1.3.4.2-3) The pinion gear shown in the illustration, is located. Illustration MO-0086
Answer A: below "2" and "4"
Answer B: between "2" and "4"
Correct Answer C: between "1" and "3"
Answer D: below "1" and "3"
 
187. (1.3.4.2-7) What type of clutch is pictured in the illustration? Illustration MO-0089
Answer A: Mechanical
Correct Answer B: Hydraulic
Answer C: Electromagnetic
Answer D: Pneumatic
 
188. (1.3.4.2-4) One advantage of electromagnetic slip couplings is.
Correct Answer A: torsional vibrations are reduced
Answer B: torque increases with a decrease in excitation current
Answer C: the coupling rapidly responds to sudden changes of load
Answer D: excitation and induction power losses appear as a change in torque instead of rotational speed between the primary and secondary elements
 
189. (1.3.1.3-3) If oil discharges are detected when the scavenging air receiver drains are blown on a slow-speed, two-stroke, turbocharged, aftercooled engine, what is the most likely oil source?
Answer A: Turbocharger lubricating oil
Answer B: Crosshead lubricating oil
Answer C: Bearing lubricating oil
Correct Answer D: Cylinder lubricating oil
 
190. (1.3.1.3-7) Upon conducting a machinery space round on a main propulsion diesel, you detect a significant amount of water discharge when blowing down the charge air cooler or scavenging air receiver drains. What should you do?
Answer A: Notify the watch or duty engineer at some point during the day work period or watch.
Answer B: Notify the first assistant engineer the next time he or she is seen.
Correct Answer C: Notify the watch or duty engineer immediately.
Answer D: Notify the chief engineer the next time he or she is seen.
191. (1.3.1.3-4) Upon conducting a machinery space round on a slow-speed main propulsion diesel, you detect a significant amount of oil discharge when blowing down the scavenging air receiver drains. What should you do?
Answer A: Notify the watch or duty engineer at some point during the day work period or watch.
Answer B: Notify the chief engineer the next time he or she is seen.
Correct Answer C: Notify the watch or duty engineer immediately.
Answer D: Notify the first assistant engineer the next time he or she is seen.
192. (1.3.1.3 -5) You are asked by the watch or duty engineer to check for any evidence for turbocharger surging. What should you check for?
Correct Answer A: By listening for cyclic changes in turbocharger sound pitch.
Answer B: By visually checking for cyclic changes in turbocharger sump oil levels.
Answer C: By visually checking for cyclic changes in charge air temperature.
Answer D: By visually checking for cyclic changes in exhaust gas temperature.
1. (2.3.1.5-1) When calculating the indicated power developed in a diesel engine cylinder, 1 horsepower is equivalent to '33,000 foot-pounds per minute'. What conversion factor would be used if the values are based on metric 'kilogram-meters per minute'?
Correct Answer A: 4500 kg-meters per minute = 1 HP
Answer B: 5500 kg-meters per minute = 1 HP
Answer C: 11000 kg-meters per minute = 1 HP
Answer D: 16500 kg-meters per minute = 1 HP
2. (2.3.1.5-2) What is the average piston speed of a five cylinder low-speed engine with a bore of 29.5 inches (75 cm), a stroke of 63 inches (160 cm), and a rated speed of 123 RPM?
Answer A: 645 ft/min (196 m/min)
Correct Answer B: 1291 ft/min (393 m/min)
Answer C: 2582 ft/min (787 m/min)
Answer D: 7749 ft/min (2362 m/min)
 
3. (2.3.1.5-3) A diesel engine indicator diagram has an area of 22 cm2 and a length of 12.5 cm. If the scale of the indicator spring is 1 mm = 1 kg/cm2, what is the cylinder mean effective pressure?
Correct Answer A: 17.6 kg/cm2
Answer B: 27.5 kg/cm2
Answer C: 34.5 kg/cm2
Answer D: 36.0 kg/cm2
 
4. (2.3.1.5-4) A six cylinder, two-stroke cycle diesel engine is 83% efficient and has a cylinder constant of 0.998 while operating with a mean effective pressure of 15 kg/cm2 at a speed of 100 RPM. What is the metric brake horsepower developed?
Answer A: 5,559 mbhp
Answer B: 6,698 mbhp
Correct Answer C: 7,455 mbhp
Answer D: 8,982 mbhp
 
5. (2.3.1.5-5) An eight cylinder, four-stroke cycle, single acting diesel engine has a 650 mm bore and a 1400 mm stroke. What will be the developed indicated metric horsepower if the average mean effective pressure is 30 kg/cm2 at a speed of 100 RPM?
Answer A: 1,689 kW
Correct Answer B: 9,111 kW
Answer C: 12,388 kW
Answer D: 24,776 kW
6. (2.3.1.5-6) The speed of the camshaft in a two-stroke cycle diesel engine, running at 950 RPM, is
Answer A: 475 RPM
Correct Answer B: 950 RPM
Answer C: 1900 RPM
Answer D: 2400 RPM
7. (2.3.1.5-7) A diesel engine cylinder has a swept volume of 125 cubic inches and a compression ratio of 13.5 to 1. What is the clearance volume in the cylinder at top dead center?
Correct Answer A: 10 cubic inches
Answer B: 12.5 cubic inches
Answer C: 13.5 cubic inches
Answer D: 14 cubic inches
 
8. (2.3.1.5-8) If the piston stroke in a four-stroke cycle diesel engine is 10 1/2 inches and the speed of rotation of the crankshaft is 720 RPM, what is the average piston speed?
Answer A: 1200 feet/minute
Correct Answer B: 1260 feet/minute
Answer C: 1320 feet/minute
Answer D: 1380 feet/minute
 
9. (2.3.1.5-9) A four cylinder, four-stroke cycle, single acting diesel engine has a 740 mm bore and a
Answer A: 1500 mm stroke. What indicated power will be developed if the average mean effective pressure is 18 kg/cm2 at a speed of 90 RPM?
Correct Answer B: 3416 kW
Answer C: 4644 kW
Answer D: 7296 kW
9290 kW
Answer A: 10. (2.3.1.6-1) Line "P" in the illustration is the. Illustration MO-0126
Answer B: line of maximum horsepower
Correct Answer C: propeller curve
Answer D: line of maximum efficiency
 
exponential line
Answer A: 11. (2.3.1.6-2) Which of the following conditions will cause the engine to operate in area "A" of the diagram shown in the illustration? Illustration MO-0126
Answer B: Fouled hull
Answer C: Damaged propeller blades
Answer D: Inclement weather
 
Correct Excessive propeller cavitation
Answer A: 12. (2.3.1.6-3) The diagram shown in the illustration may be used to determine the proper operation of the engine. Which of the following statements represents an accurate interpretation of the diagram? Illustration MO-0126
Answer B: The engine may be operated in any area of the diagram provided steps are taken to reposition the load indicator.
Answer C: Operation within area "B" is permitted for extended time periods provided no changes are made to the air intake system.
Correct Answer D: Ideally the engine should be operated in area "A"; however, it is permissible to intermittently operate the engine in area "B".
 
Assuming the load indicator reads 90% and the engine speed is at 80% the engine can be operated until maintenance requirements become apparent.
Answer A: 13. (2.3.1.6-4) Which of the following conditions would NOT be considered a valid reason for the diesel engine to operate in the area indicated by letter "B" shown in the illustration? Illustration MO-0126
Answer B: Operating the vessel in shallow water
Answer C: Operating with a fouled or damaged propeller
Answer D: Operating the vessel against high winds and current
 
Correct Operating with minimal hull drag and under light draft
Answer A: 14. (2.3.1.7-1) In the pressure-volume diagram shown in the illustration, fuel injection occurs at point . Illustration MO-0035
Answer B: e
Answer C: f
Correct Answer D: c
 
d
Answer A: 15. (2.3.1.7-2) An indicator card or pressure-volume diagram, shows graphically the.
Answer B: compression ratio of the engine
Answer C: volume of the engine
Answer D: relationships between pressure and temperature during one stroke of the engine
Correct relationships between pressure and volume during one cycle of the engine
Answer A: 16. (2.3.1.7-3) The indicator card shown in the illustration is produced with a/an. Illustration MO-0108
Correct Answer B: rotating drum
Answer C: sliding camshaft
Answer D: oscillating drum
balanced-diaphragm indicator
Answer A: 17. (2.3.1.7-4) On the indicator card shown in the illustration, lines 'A' and 'B' indicate . Illustration MO-0108
Answer B: the end of ignition
Answer C: bottom dead center
Answer D: the end of injection
Correct top dead center
Answer A: 18. (2.3.1.7-5) In the pressure-volume diagram, shown in the illustration, what occurs between points "e" and "f"? Illustration MO-0035
Answer B: The exhaust valve closes.
Answer C: The intake ports close.
Correct Answer D: Pressure in the cylinder decreases.
 
Volume in the cylinder decreases.
Answer A: 19. (2.3.1.7-6) In the pressure-volume diagram, shown in the illustration, the volume line is divided into 16 units indicating. Illustration MO-0035
Answer B: a cylinder volume of 166 cubic inches
Answer C: compression pressure is 1600 PSI
Correct Answer D: a 16 to 1 compression ratio
16 of crankshaft motion between lines A and B
Answer A: 20. (2.3.1.7 -7) In the pressure-volume diagram shown in the illustration, curve 'A-d' indicates . Illustration MO-0035
Correct Answer B: combustion at approximately constant pressure
Answer C: opening of exhaust valves
Answer D: fuel injection after dribble
start of fuel injection
Answer A: 21. (2.3.1.7-8) In the pressure-volume diagram, shown in the illustration, what is indicated to have occurred by the line connecting points 'd' and 'e'? Illustration MO-0035
Correct Answer B: The combustion gases have expanded.
Answer C: The crankshaft has rotated 90.
Answer D: Pressure and volume have increased.
 
The fuel/air charge is compressed.
Answer A: 22. (2.3.1.8-1) On the cylinder indicator diagram illustrated, the dotted line indicated as 'L' is describing the. Illustration MO-0033
Correct Answer B: cylinder pressure without injection
Answer C: firing pressure at 90 degrees crank angle
Answer D: beginning of compression
power expansion curve
Answer A: 23. (2.3.1.8-2) Which of the indicator diagrams illustrated depicts the condition that should be corrected by retarding only the timing? Illustration MO-0029
Correct Answer B: A
Answer C: B
Answer D: C
D
Answer A: 24. (2.3.1.8-3) On the indicator card shown in the illustration, lines 'A' and 'B' indicate. Illustration MO-0108
Correct Answer B: top dead center
Answer C: bottom dead center
Answer D: the end of injection
the end of ignition
Answer A: 25. (2.3.1.1-1) Diesel engines are classified as reciprocating internal combustion engines because they
Answer B: use energy from fuel burned outside their cylinders
Answer C: burn fuel in a combustion chamber that moves back and forth
Correct Answer D: burn fuel in a closed chamber which imparts linear motion to pistons
use a continuous combustion process to impart rotary motion to the pistons
Answer A: 26. (2.3.1.1-3) What determines the number of events occurring in a cycle of operation in an internal combustion engine?
Answer B: Crankshaft revolution
Correct Answer C: Method of air charging a cylinder and expelling exhaust gases
Answer D: Distance a piston travels during a stroke
 
Number of pistons
Answer A: 27. (2.3.1.1-2) The thermal energy produced by an internal combustion engine is transformed into
Answer B: combustion energy
Answer C: internal energy
Answer D: external energy
 
Correct mechanical energy
Answer A: 28. (2.3.1.1-4) In describing engine operation, what does the term "cycle" mean?
Answer B: One stroke of a piston.
Correct Answer C: The sequence of events that produce a power pulse.
Answer D: One rotation of the engine crankshaft.
 
All of the above.
Answer A: 29. (2.3.1.1-5) The highest pressure in a diesel engine cylinder normally occurs.
Answer B: at TDC
Answer C: before TDC
Correct Answer D: after TDC
 
during air starting
Answer A: 30. (2.3.1.1-6) Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion cycle which is.
Answer B: entirely constant volume
Answer C: entirely constant pressure
Correct Answer D: a combination of constant volume and constant pressure
a combination of constant temperature and constant pressure
Answer A: 31. (2.3.1.1-7) The load is always placed on the lower half of the main bearings in a/an.
Correct Answer B: two-stroke cycle engine
Answer C: four-stroke cycle engine
Answer D: reverse cycle engine
double acting engine
Answer A: 32. (2.3.1.1-8) The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speed. In maintaining this relationship, the camshaft drive causes the camshaft to rotate at
Answer B: one-fourth crankshaft speed in a four-stroke cycle diesel engine
Answer C: one-half crankshaft speed in a two-stroke cycle diesel engine
Correct Answer D: crankshaft speed in a two-stroke cycle diesel engine
 
two times crankshaft speed in a two-stroke cycle diesel engine
Answer A: 33. (2.3.1.1-9) Which of the terms listed below represents the operational speed at which excessive engine vibration is created?
Answer B: Non-harmonic speed.
Correct Answer C: Critical speed.
Answer D: Maximum speed.
 
Design maximum speed.
Answer A: 34. (2.3.1.1-10) The bore of a diesel engine cylinder describes the.
Answer B: swept volume of the cylinder
Correct Answer C: inside diameter of the cylinder
Answer D: piston displacement in the cylinder
length of the piston stroke
Answer A: 35. (2.3.1.1-11) The cubic inch (or liter) displacement of a cylinder is determined by the diameter of the piston and the.
Answer B: length of the crankshaft
Answer C: volume of the clearance space
Answer D: weight of the piston
 
Correct length of the stroke
Answer A: 36. (2.3.1.1-12) The compression ratio of a diesel engine refers to the ratio between the. o (a) piston area to connecting rod length
Correct Answer B: cylinder volumes at top dead center and at bottom dead center
Answer C: engine cylinder size to piston size
Answer D: number of compression strokes for a given horsepower
 
37. (2.3.1.1-13) If the compression ratio is increased on any diesel engine,.
Answer A: the expansion ratio will decrease
Answer B: combustion will be slowed down
Answer C: thermal efficiency will decrease
Correct Answer D: thermal efficiency will increase
 
38. (2.3.1.1-14) The theoretical minimum compression ratio necessary to ensure compression ignition in a direct injection diesel engine is.
Answer A: 10:1
Correct Answer B: 0.500694444444444
Answer C: 16:1
Answer D: 20:1
 
39. (2.3.1.1-15) Which of the following relationships exist between the temperature developed in a combustion space, and the compression ratio of the engine?
Correct Answer A: Higher compression ratios create higher temperature.
Answer B: Higher temperatures create higher compression ratios.
Answer C: Lower temperatures create higher compression ratios.
Answer D: Higher compression ratios create lower temperatures.
 
40. (2.3.1.1-16) The ratio of the brake horsepower to the indicated horsepower of a diesel engine is its
Answer A: thermal efficiency
Correct Answer B: mechanical efficiency
Answer C: brake thermal efficiency
Answer D: volumetric efficiency
 
41. (2.3.1.1-17) The most important factor in engine performance is the actual power output at the end of the crankshaft available for doing work. This is known as.
Answer A: indicated horsepower
Correct Answer B: brake horsepower
Answer C: net horsepower
Answer D: friction horsepower
 
42. (2.3.1.1 -18) The average pressure exerted on a piston during each power stroke is termed
Answer A: indicated horsepower
Correct Answer B: mean effective pressure
Answer C: exhaust back pressure
Answer D: compression pressure
 
43. (2.3.1.2-1) Most practical diesel engines today operate on a cycle which is a combination of the Diesel and Otto cycles. In this process, compression ignition .
Correct Answer A: begins on a constant volume basis
Answer B: begins on a constant pressure basis
Answer C: ends on a constant volume basis
Answer D: begins and ends on a constant volume basis
 
44. (2.3.1.2-2) The pressure-volume diagrams illustrated are of four internal combustion engine cycles. Which one represents the theoretical diesel cycle? Illustration MO-0102
Answer A: A
Correct Answer B: B
Answer C: C
Answer D: D
45. (2.3.1.2 -3) If point #1 in the diagram shown is the beginning of gas compression, which of the cycles listed is being illustrated? Illustration MO-0036
Answer A: Otto
Correct Answer B: Diesel
Answer C: Gas Turbine
Answer D: Rankine
46. (2.3.11.1-1) The minimum fuel oil delivery pressure required for efficient injection depends primarily on the.
Answer A: degree of cylinder air turbulence
Correct Answer B: maximum pressure in the engine cylinders during injection
Answer C: quantity of the fuel to be injected
Answer D: duration of the injection delay period
 
47. (2.3.11.1-2) Fuel injection systems are designed to primarily meter fuel, atomize fuel, and
Answer A: create turbulence in the combustion chamber
Answer B: aid in completing cylinder scavenging
Correct Answer C: inject fuel at the proper time
Answer D: minimize fuel penetration into the cylinder
 
48. (2.3.11.1-3) The degree of fuel atomization in a diesel engine cylinder depends primarily on
Correct Answer A: the size of the holes in the fuel nozzle
Answer B: timing of the pump
Answer C: supply pressure to the pump
Answer D: shape of the combustion chamber
49. (2.3.11.1-4) The purpose of the delivery check valve used in a diesel fuel injection jerk pump is to
Correct Answer A: assist in a quick cutoff of fuel injection
Answer B: allow oil backflow from the injector to the helix
Answer C: reduce fuel oil pressure between injection strokes
Answer D: meter the quantity of fuel delivered
50. (2.3.11.6 -1) Injection pressure in a common rail fuel system is controlled by .
Answer A: engine speed
Answer B: varying the fuel pump piston stroke
Answer C: varying the injector needle valve clearance
Correct Answer D: a bypass valve
51. (2.3.11.5 -1) The component shown in the illustration would be identified as a/an . Illustration MO-0097
Answer A: slow-speed engine cylinder liner lubricator
Correct Answer B: slow-speed engine fuel pump
Answer C: centrifugal flyweight governor
Answer D: injector cooling system pump
52. (2.3.11.5-2) The component identified as item No.15 is used to. Illustration MO-0016
Answer A: test injector popping pressure
Correct Answer B: stop fuel delivery to the injector
Answer C: advance fuel pump timing
Answer D: increase the fuel pump delivery pressure
53. (2.3.11.5-3) In the large slow-speed main propulsion diesel engine shown in the illustration, the part labeled "G" is the. Illustration MO-0003
Correct Answer A: fuel oil pump
Answer B: jacket water pump
Answer C: crankcase exhaust fan
Answer D: lube oil pump
54. (2.3.11.5 -4) According to the illustration, initial timing of fuel injection into the cylinder is controlled with the component that is identified as the letter. Illustration MO-0097
Correct Answer A: C
Answer B: H
Answer C: K
Answer D: I
 
55. (2.3.11.5-5) According to the illustration, fuel cutoff timing in the cylinder is controlled with the component that is identified as the letter. Illustration MO-0097
Answer A: C
Answer B: H
Answer C: K
Correct Answer D: I
56. (2.3.11.3-1) Regarding the fuel injector shown in the illustration, the purpose of piece #38 is to . Illustration MO-0059
Answer A: adjust the fuel rack spring tension
Correct Answer B: filter the fuel
Answer C: maintain fuel pressure at a preset level
Answer D: relieve excess fuel pressure to the suction side of the pump
 
57. (2.3.11.3-2) The amount of fuel delivered by a unit injector is controlled by the.
Answer A: camshaft
Answer B: main spring
Correct Answer C: rack position
Answer D: engine speed
58. (2.3.11.3-3) In a unit injector, an upper helix and lower helix are machined in the lower part of the plunger for.
Answer A: facilitating plunger rotation
Answer B: positioning the control sleeve
Correct Answer C: accurate metering of the fuel oil
Answer D: eliminating injection lag
59. (2.3.11.3-4) The control rack to a unit injector regulates fuel delivery by.
Answer A: altering spring tension on the plunger
Correct Answer B: rotating the plunger and position of the helix
Answer C: regulating the lift of the check valve
Answer D: altering the actual length of the plunger stroke
60. (2.3.11.3-5) Which type of diesel engine fuel nozzle is shown in the illustration? Illustration MO-0059
Correct Answer A: Multi-hole
Answer B: Open
Answer C: Self-cleaning
Answer D: Pintle
 
61. (2.3.18.1-1) A main propulsion diesel engine is normally shutdown by.
Answer A: shutting off the air supply
Answer B: overspeeding the engine
Correct Answer C: securing the fuel supply
Answer D: securing the ignition system
 
62. (2.3 .18.1-2) The overspeeding of the diesel engine driving an electric generator could cause
Answer A: low voltage trip to trip
Answer B: reverse power trip to trip
Correct Answer C: damage to the field windings
Answer D: excessive exhaust temperatures
 
63. (2.3.18.1-3) A normally operating diesel engine is shutdown by
Answer A: shutting off the air supply
Answer B: overspeeding the engine
Correct Answer C: securing the fuel supply
Answer D: securing the ignition system
 
64. (2.3.18.1-4) Load control on a diesel engine is accomplished by.
Answer A: regulating the speed of the turbocharger
Correct Answer B: regulating the amount of fuel admitted to the engine
Answer C: regulating the speed of the fuel oil transfer pump
Answer D: changing engine timing
 
65. (2.3.18.1-5) Diesel engine automated control systems may utilize sensing devices of dual function, with sensing ranges providing both alarm and engine shut down capability. Which of the key points listed would only require an alarm sensor?
Answer A: Lube oil pressure and temperature
Answer B: Jacket water pressure and temperature
Answer C: Engine overspeed
Correct Answer D: Lube oil sump level
 
66. (2.3.18.3-3) The pneumatic circuit shown in the illustration is part of a control system used with large low-speed diesel engines. The arrangement may be used to control. Illustration MO-0118
Answer A: bridge tachometer variations
Answer B: the proportional offset of the throttle signal
Correct Answer C: main engine speed
Answer D: emergency clutching operations
 
67. (2.3.18.3-7) The 3-position, 4-way directional control valve with a 30 bar output at "ee" as shown in the illustration (MO-0116) is a blocking valve associated with the engine turning gear. Which of the following statements describes its function when incorporated into a slow-speed diesel engine starting control air distributor as shown in the illustration (MO-0053)? Illustrations MO-0053 and MO- 116
Answer A: The blocking valve is used to interrupt the supply air at port "C" when the turning gear is engaged.
Answer B: The blocking valve is used to interrupt the control air at port "A" when the turning gear is disengaged.
Correct Answer C: The blocking valve is used to interrupt the control air at port "A" when the turning gear is engaged.
Answer D: The blocking valve is used to interrupt the supply air at port "C" when the turning gear is disengaged.
68. (2.3.18.3-11) Which of the following statements describes the operation of the circuit shown in the illustration? Illustration MO-0114
Answer A: The output of "2" will always be less than the input at "1" by 0.35 bar (35 kPa), to prevent engine damage due to operation in the critical speed range.
Answer B: A gradual rise of the input signal to "1" will cause a multiple stepped output from "2" proportional to the input signal.
Answer C: The output signal from "2" will be equal to the setpoint of '17A' only when the input is less than the setpoint of '17B', permitting the transition signal to become modulated.
Correct Answer D: The output from "2" is equal to the input to "1" except when the input of "1" is between the setpoints of '17A' and '17B', when it will remain at the value of '17A'.
 
69. (2.3.18.3-15) The device represented by the symbol "B" in the illustration is used to. Illustration MO-0115
Answer A: remove all moisture from the system
Answer B: lubricate the air supply
Answer C: reduce the temperature of the air supply as a result of the heat of compression
Correct Answer D: remove most contaminants present in the air supply
 
70. (2.3.17.2-1) Which of the types of reduction gearing listed is best suited for medium-speed main propulsion units?
Answer A: Hypoid
Correct Answer B: Helical
Answer C: Cyclical
Answer D: Spur
71. (2.3.17.2-2) In the reversing reduction gear shown in the illustration, the forward and reverse main pinions are in constant mesh with the main gear. This means the. Illustration MO-0085
Answer A: synchromesh coupling will maintain transition torque control
Answer B: set that is clutched in will rotate as idlers driven from the main gear
Correct Answer C: idling gears rotate in a direction opposite to their rotation when carrying load
Answer D: clutches are engaged by a reduction in control air pressure
72. (2.3.17.2-4) Reduction gear casings are vented in order to.
Answer A: allow windage to exist for cooling the gears
Correct Answer B: avoid a buildup of pressure within the gear case
Answer C: minimize lube oil foaming within the case
Answer D: allow for axial clearance between the gears
 
73. (2.3.17.2-5) A diesel engine with a full speed of 1000 RPM drives a propeller at 300 RPM. What is the speed reduction ratio?
Answer A: 0.3 to 1
Correct Answer B: 3.33 to 1
Answer C: 33 to 1
Answer D: 300 to 1
 
74. (2.3.17.3-2) The main engine thrust bearing shown in the illustration contains how many thrust shoes? Illustration MO-0121
Answer A: 6
Answer B: 10
Correct Answer C: 12
Answer D: 20
75. (2.3.17.3-4) How is lubrication provided to the device shown in the illustration? Illustration MO-0120
Answer A: The lubrication system closely resembles the system used with standard line shaft bearings.
Answer B: A separate system containing oil under extremely high-pressure is used due to its ability to provide a high film strength.
Answer C: Only silicate ester based synthetic oils have the capability and necessary characteristics to be used in this type of application.
Correct Answer D: The lube oil enters through the supply pipes shown as #11 and eventually drains to the main engine sump.
76. (2.3.17.3-6) What type of bearing is shown in the illustration? Illustration MO-0120
Answer A: Axial/radial bearing
Answer B: Collar bearing
Answer C: Kingsbury thrust bearing
Correct Answer D: Michell bearing
 
77. (2.3.17.3-8) What prevents the thrust bearing blocks shown in the illustration from rotating within the housing? Illustration MO-0120
Answer A: The bearing blocks are massive and their weight provides sufficient force to prevent rotation.
Correct Answer B: Found within the thrust bearing cap or cover are extended protrusions to position the thrust shoe segments and maintain minimum clearance.
Answer C: The bearing assembly is specifically designed to allow for rotation, permitting the transmittal of axial forces across a greater surface area and minimizing loading densities.
Answer D: The thrust shoes are dovetailed into the collar.
 
78. (2.3.2.1-9) The minimum speed an engine must attain before ignition can occur depends upon
Answer A: the type and size of the engine
Answer B: the condition of the engine
Answer C: ambient temperature
Correct Answer D: all of the above
 
79. (2.3.2.1-6) Heat for igniting the fuel oil in the cylinder of a diesel engine is generated by the
Answer A: electronic ignition system
Correct Answer B: compression of air by the piston
Answer C: friction in the fuel injector
Answer D: fuel oil heating system
80. (2.3.2.1-5) The main operating characteristic of diesel engines which distinguishes them from other internal combustion engines is the.
Answer A: method of supplying air
Answer B: cooling system
Correct Answer C: method of igniting fuel
Answer D: valve operating mechanism
81. (2.3.2.1-8) Theoretical perfect combustion in a diesel engine yields by-products of.
Answer A: aldehydes and carbon dioxide
Answer B: water vapor and carbon monoxide
Answer C: nitrogen and carbon monoxide
Correct Answer D: water vapor and carbon dioxide
82. (2.3.2.1-7) The formation of carbon monoxide in diesel exhaust gases is reduced by_
Answer A: spraying water into the exhaust pipe
Answer B: keeping the exhaust system free of carbon deposits
Correct Answer C: maintaining proper combustion and scavenging
Answer D: avoiding light load operation
 
83. (2.3.2.1-3) Turbulence of the compressed air charge in a diesel engine cylinder increases
Answer A: ignition lag
Answer B: piston side thrust
Correct Answer C: the efficiency of fuel combustion
Answer D: compression pressure
 
84. (2.3.2.1-11) In a diesel engine, after ignition of the fuel occurs, but before the piston reaches TDC, there is little change in the cylinder.
Answer A: temperature
Answer B: pressure
Answer C: energy
Correct Answer D: volume
 
85. (2.3.2.1-1) In the starting process of a diesel engine, the main object is to attain the compression conditions sufficient to.
Answer A: turn the flywheel
Answer B: reduce friction
Answer C: overcome inertia
Correct Answer D: ignite the fuel
86. (2.3.2.1-4) The greatest turbulence in a diesel engine cylinder is created by the.
Correct Answer A: shape of the combustion chamber
Answer B: fuel injection spray pattern
Answer C: cylinder swept volume
Answer D: degree of penetration of the fuel oil droplets
87. (2.3.2.2-2) What is the term given to the process of breaking up fuel oil into very fine particles for better combustion?
Answer A: Settling
Answer B: Straining
Answer C: Spraying
Correct Answer D: Atomizing
 
88. (2.3.2.2-3) Proper atomization of fuel in diesel engine combustion chambers will.
Answer A: affect the injection pressure
Correct Answer B: improve combustion
Answer C: reduce compression pressure
Answer D: decrease power output
 
89. (2.3.2.2-4) Fuel oil penetration into the cylinder of a diesel engine is.
Answer A: dependent on air turbulence
Correct Answer B: reduced by finer atomization
Answer C: increased by finer atomization
Answer D: non-existent in the precombustion chamber system
90. (2.3.2.2-5) Fuel droplets injected into a diesel engine cylinder must have adequate penetration to
Answer A: prolong the ignition delay period
Answer B: ensure the beginning of fuel injection
Correct Answer C: thoroughly utilize the air charge
Answer D: allow controlled fuel combustion
91. (2.3.2.2-1) Maintaining the proper fuel oil temperature will result in
Answer A: the elimination of valve wear
Correct Answer B: improved atomization
Answer C: a decrease in cylinder blow-by
Answer D: a decrease in cylinder mean effective pressure
92. (2.3.2.3-1) A diesel engine operating at a light load, when compared to operating at heavy load has an air/fuel ratio that is.
Correct Answer A: higher
Answer B: lower
Answer C: equal
Answer D: directly proportional
 
93. (2.3.2.3-2) As engine RPM is increased from idle speed to full load speed, which of the conditions listed will decrease?
Answer A: Compression ratio
Correct Answer B: Air/Fuel ratio
Answer C: Compression pressure
Answer D: Lube oil pressure
 
94. (2.3.3.1-2) The time between injection and ignition of the fuel is known as.
Answer A: turbulence lag
Answer B: afterburning ratio
Answer C: injection lag
Correct Answer D: ignition delay
 
95. (2.3.3.1-3) When is fuel injected into a cylinder of diesel engines?
Answer A: Before air in the cylinder is compressed.
Correct Answer B: After air in the cylinder is compressed.
Answer C: After combustion gases in the cylinder have expanded.
Answer D: As air is taken into the cylinder.
 
96. (2.3.3.1-1) For a given fuel, a change in the compression ratio will affect the ignition lag by which of the listed means?
Answer A: An increase in compression ratio will increase the ignition lag.
Correct Answer B: An increase in compression ratio will decrease the ignition lag.
Answer C: A decrease in compression ratio will decrease the ignition lag.
Answer D: A decrease in ignition lag will increase the compression ratio.
 
97. (2.3.3.1-4) Which area of the indicator diagram illustrated, indicates the ignition delay period in a diesel engine cylinder? Illustration MO-0033
Answer A: G
Answer B: H
Correct Answer C: J
Answer D: K
 
98. (2.3.3.2-2) The rate of pressure rise during the period following fuel ignition in a diesel engine is influenced by the length of the ignition delay period and the.
Answer A: valve overlap
Answer B: volumetric efficiency
Correct Answer C: turbulence of the air charge
Answer D: fuel efficiency
 
99. (2.3.3.2-1) The pressure in an operating diesel engine cylinder continues to rise for a short period after the piston passes top dead center as a result of the.
Correct Answer A: expansion during the combustion process
Answer B: exhaust and intake valves just closing
Answer C: maximum compression pressure is just being attained
Answer D: fuel injection occurring at that point and combustion begins
100. (2.3.3.2-3) On the cylinder indicator diagram illustrated, the maximum rise in pressure occurs during the period labeled as. Illustration MO-0033
Answer A: G
Correct Answer B: H
Answer C: J
Answer D: K
 
101. (2.3.3.3-1) Which statement about diesel engine combustion is true?
Answer A: Combustion does not begin until the piston starts down on the power stroke.
Answer B: Maximum combustion pressure is reached before TDC.
Answer C: Turbulence in the cylinder causes a delay in ignition.
Correct Answer D: Maximum cylinder firing pressure is not developed until the piston passes TDC.
102. (2.3.3.4-1) Fuel combustion in a diesel engine cylinder should begin just before the piston reaches top dead center and should.
Answer A: end when fuel injection has been completed
Answer B: end at bottom dead center
Correct Answer C: continue through the afterburning period
Answer D: be completed exactly at top dead center
103. (2.3.3.4 -2) On the cylinder indicator diagram illustrated, the dotted line indicated as 'L' is describing the. Illustration MO-0033
Answer A: power expansion curve
Answer B: beginning of compression
Correct Answer C: cylinder pressure without injection
Answer D: firing pressure at 90 degrees crank angle
104. (2.3.3.4-3) Which area of the indicator diagram illustrated, indicates the afterburning period in a diesel engine cylinder? Illustration MO-0033
Answer A: G
Answer B: H
Answer C: J
Correct Answer D: K
105. (2.3.5.1 -1) Item labeled 'R' as shown in section 6 of the illustration is identified as the . Illustration MO-0025
Answer A: air filter
Answer B: exhaust manifold
Answer C: non-return scavenge valve
Correct Answer D: aftercooler
 
106. (2.3.5.1-2) In the illustrated engine, the fuel camshaft gear drive housing is indicated as letter . Illustration MO-0003
Answer A: B
Correct Answer B: F
Answer C: G
Answer D: Z
107. (2.3.5.1 -3) In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?
Answer A: Bed plate
Answer B: Column
Answer C: Entablature
Correct Answer D: Tie rod
 
108. (2.3.5.1-4) In the diesel engine illustrated, what part is under compression when firing is taking place in a particular cylinder? Illustration MO-0003
Answer A: Tie rod
Answer B: Piston rod nut
Answer C: Lubrication telescopes
Correct Answer D: Piston rod
 
109. (2.3.5.1-5) In the pressure-volume diagram shown in the illustration, the atmospheric pressure line is indicated by line. Illustration MO-0035
Answer A: A
Answer B: B
Correct Answer C: C
Answer D: de
 
110. (2.3.5.1-6) Which of the indicator diagrams illustrated depicts the condition that should be corrected by retarding only the timing? Illustration MO-0029
Correct Answer A: A
Answer B: B
Answer C: C
Answer D: D
 
111. (2.3.5.1-7) In diesel engines designed with a crosshead, the motion of the piston rod can be described as.
Answer A: reciprocating at the crank pin, rotary at the piston pin
Answer B: straight rotation
Answer C: reciprocating at the piston pin, rotary at the crank pin
Correct Answer D: straight reciprocation
112. (2.3.5.1-8) Which of the indicator diagrams illustrated indicates the condition that should be corrected by retarding the timing, and the fitting of thicker shims to the connecting rod? Illustration MO-0029
Answer A: A
Answer B: B
Answer C: C
Correct Answer D: D
113. (2.3.5.1-9) In a large slow-speed propulsion diesel engine, the side thrust on the crosshead is the direct result of.
Answer A: the piston rod acting against the crosshead during the power stroke
Correct Answer B: the angularity of the connecting rod against the crosshead during the power stroke
Answer C: the velocity of the crank pin during the power stroke
Answer D: cylinder pressure acting against the piston crown
114. (2.3.5.1-10) While underway, which of the following would be the FIRST step in reversing a direct reversing large, slow-speed, main propulsion, diesel engine?
Answer A: Manually trip the overspeed device.
Correct Answer B: Set the fuel rack to zero.
Answer C: Disengage the safety interlock.
Answer D: Slide the camshaft to the neutral position.
 
115. (2.3.5.1-1 1) In a large slow-speed propulsion diesel engine, the force applied to the piston is
Answer A: against the crosshead during power stroke and away from the crosshead during the compression stroke
Answer B: against the crosshead during the compression stroke and away from the crosshead during the power stroke
Correct Answer C: against the crosshead during the power and compression strokes
Answer D: away from the crosshead during the power and compression strokes
 
116. (2.3.5.1-12) Cast iron pistons used in large propulsion diesel engines are constructed with
Answer A: no taper for the entire length
Answer B: the skirt being tapered and smaller than the crown
Answer C: the skirt being tapered and larger than the crown
Correct Answer D: the crown being tapered and smaller than the skirt
117. (2.3.5.1 -13) Which of the following procedures should be carried out when a large, low-speed, diesel engine is operated with one cylinder secured?
Answer A: Lubrication to the defective cylinder should be increased.
Answer B: Cooling water temperature to the engine should be increased.
Answer C: Only the turbocharger speed should be reduced.
Correct Answer D: Engine speed should be reduced.
118. (2.3.5.1-14) In the slow-speed diesel engine shown in the illustration, the part labeled "E" is the . Illustration MO-0003
Answer A: high-pressure lube oil line
Answer B: low-pressure lube oil line
Correct Answer C: high-pressure fuel line
Answer D: low-pressure fuel line
 
119. (2.3.5.1-15) During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to changing the engine rotation for a vessel with moderate headway?
Answer A: The way of the vessel
Answer B: Flywheel inertia
Answer C: Securing cylinder lubricators
Correct Answer D: Admission of reversing start air
120. (2.3.5.1-16) The line identified as "I" in the illustration is used to. Illustration MO-0066
Answer A: deliver fuel oil to the injector
Correct Answer B: supply lubricating oil for actuating the exhaust valve
Answer C: deliver cooling water to the exhaust valve actuating device
Answer D: exhaust gas and vapors from the power cylinder
 
121. (2.3.5.1-17) Which letter represents the scavenging air system non-return valve in the illustration? Illustration MO-0003
Correct Answer A: P
Answer B: Q
Answer C: W
Answer D: U
122. (2.3.5.1-18) Valve cages are used on some large diesel engines to.
Answer A: reduce wear on the valve stem
Answer B: permit the use of alloy valve seat materials
Answer C: reduce heat transfer from the valve seat
Correct Answer D: facilitate valve removal for servicing
123. (2.3.5.1-19) In the diesel engine shown in the illustration, the purpose of the part labeled "P" is to . Illustration MO-0003
Answer A: boost the scavenge air pressure
Correct Answer B: ensure one way air flow into the air header
Answer C: provide turbulence in the scavenge air
Answer D: cool the scavenge air
124. (2.3.5.1 -20) A diesel engine crankcase ventilation system .
Answer A: prevents spark generation
Correct Answer B: removes combustible gases
Answer C: determines the level of combustible gases
Answer D: provides inert gas generation in crankcase
125. (2.3.5.1-21) A safety crankcase cover differs from other diesel engine access doors in that it is fitted with a.
Correct Answer A: spring-loaded pressure plate
Answer B: handwheel
Answer C: nut-operated clamp
Answer D: large gasket
 
126. (2.3.5.1-22) The part labeled "X" shown in the illustration is a. Illustration MO-0003
Answer A: fuel line
Answer B: waterline
Correct Answer C: lube oil line
Answer D: control linkage
127. (2.3.5.1-23) According to the illustration, fuel delivery to the cylinder is terminated and controlled with the component that is identified as the letter. Illustration MO-0097
Answer A: C
Answer B: H
Answer C: K
Correct Answer D: I
 
128. (2.3.5.1-24) Which of the following processes is indicated by the flow arrows shown in the illustration? Illustration MO-0026
Correct Answer A: Relief of excessively high-pressure gases from the cylinder.
Answer B: Cooling water bypass flow to the heat sink.
Answer C: Return flow of excess fuel oil from the injector.
Answer D: Return air flow during start-up upon achieving ignition.
 
129. (2.3.5.1 -25) Which of the listed design features is most common with a two-stroke cycle, low- speed main propulsion diesel engine?
Correct Answer A: Piston rod and crosshead construction
Answer B: 90 degree 'V' configuration
Answer C: Double acting trunk type pistons
Answer D: Single reduction gearing
 
130. (2.3.5.1-26) There are two glands provided where the piston rod exits the cylinder shown in the illustration. The purpose of the top gland is to. Illustration MO-0083
Correct Answer A: seal against scavenge air leakage
Answer B: prevent crankcase oil leaking out
Answer C: maintain crankcase vacuum
Answer D: maintain crankcase pressure
 
131. (2.3.5.1-27) The diesel engine shown in the illustration, the exhaust manifold is indicated by the letter. Illustration MO-0003
Answer A: A
Answer B: B
Answer C: P
Correct Answer D: U
 
132. (2.3.5.1-28) The opening of an exhaust valve on a modern, large, low-speed, main propulsion diesel engine, may be actuated by.
Answer A: direct action of the overhead camshaft
Answer B: compressed air pressure
Correct Answer C: hydraulic "push rods"
Answer D: direct action of the main piston moving down
133. (2.3.5.1-29) The exhaust ports shown in the illustration are identified with the letter ''. Illustration MO-0003
Answer A: B
Correct Answer B: Q
Answer C: T
Answer D: U
 
134. (2.3.5.1-30) The closing of the exhaust valves used on a modern, large, low-speed, main propulsion diesel engine may be directly provided by .
Answer A: mechanical push rods
Correct Answer B: compressed air pressure
Answer C: hydraulic pressure
Answer D: exhaust gas pressure
135. (2.3.5.1-31) The insertion of shims between the foot of a marine type connecting rod and a bearing box would result in.
Correct Answer A: increased compression ratio
Answer B: decreased compression ratio
Answer C: increased bearing clearance
Answer D: decreased bearing clearance
 
136. (2.3.5.2-12) The fuel injector for the diesel engine shown in the illustration, is identified as . Illustration MO-0122
Correct Answer A: "19"
Answer B: "H"
Answer C: "M"
Answer D: "Z"
 
137. (2.3.5.2-6) Which letter represents the top deck (valve) cover of the engine shown in the illustration? Illustration MO-0122
Correct Answer A: A'
Answer B: H'
Answer C: 8'
Answer D: None of the above are correct.
 
138. (2.3.5.2-10) Device 'E' shown in the illustration is known as the. Illustration MO-0122
Answer A: lube oil manifold
Answer B: extrusion tube assembly
Answer C: overspeed trip shaft
Correct Answer D: fuel manifold
 
139. (2.3.5.2-14) The diesel engine water inlet jumper illustrated is represented by the letter or number . Illustration MO-0122
Answer A: W'
Correct Answer B: M'
Answer C: N'
Answer D: 14'
 
140. (2.3.5.2-17) Component 'U' of the diesel engine shown in the illustration is called the . Illustration MO-0122
Answer A: frequency tuner
Correct Answer B: crankshaft counterweight
Answer C: frame stiffener
Answer D: main bearing support assembly
 
141. (2.3.5.2-22) The diesel engine wrist pin in the illustration is indicated by the component labeled . Illustration MO-0122
Correct Answer A: 7'
Answer B: 17'
Answer C: G'
Answer D: S'
 
142. (2.3.5.2-27) Item '17' in the illustration is the dipstick. When should the length of the dipstick be changed? Illustration MO-0122
Answer A: If the operating oil level of the engine is consistently below normal, it will be necessary to use a longer dipstick.
Answer B: If sludge buildup on the bottom of the pan becomes excessive, it will become necessary to shorten the dipstick to accommodate for the false oil level reading.
Answer C: When changing the oil in an operating engine, it may become necessary to use a longer stick to obtain the exact location of the oil level at all times.
Correct Answer D: In most situations this would never be done.
143. (2.3.5.2 -3) In a two-stroke cycle, opposed-piston, diesel engine, one crankshaft operates several crank angles in advance of the other crankshaft to .
Correct Answer A: allow the exhaust ports to open and close before the inlet ports close
Answer B: allow the scavenge ports to open and close simultaneously with the exhaust ports
Answer C: prevent scavenge air pressure buildup in the cylinders
Answer D: prevent the exhaust piston from reaching TDC and BDC before the intake piston
144. (2.3.5.2-15) The water inlet manifold for the diesel engine shown in the illustration is represented by the letter or number. Illustration MO-0122
Answer A: "M"
Correct Answer B: "N"
Answer C: "W"
Answer D: "13"
 
145. (2.3.5.2 -20) The diesel engine component labeled "3", shown in the illustration is called the . Illustration MO-0122
Answer A: scavenging air space
Answer B: cylinder liner
Answer C: head valve assembly
Correct Answer D: cylinder head
146. (2.3.5.2-23) The diesel engine connecting rods shown in the illustration are distinctively named . Illustration MO-0122
Correct Answer A: fork and blade
Answer B: male and female
Answer C: hook and nail
Answer D: left hand and right hand
 
147. (2.3.5.2-5) Which of the listed cylinder head design features is shown in the illustration? Illustration MO-0013
Answer A: The valve cages are provided for the exhaust valves.
Answer B: The engine is equipped with a dry liner.
Answer C: A gastight seal is provided by a gasket between the cylinder head and cylinder liner.
Correct Answer D: The engine cylinder head is fitted with replaceable valve seats.
148. (2.3.5.2-7) Which of the following represents the diesel engine camshaft shown in the illustration and its relative rotating speed? Illustration MO-0122
Answer A: "B" is the camshaft and it rotates at one-half of the crankshaft speed.
Correct Answer B: "B" is the camshaft and its rpm will match that of the flywheel.
Answer C: "T" is the camshaft and its speed equals crankshaft speed.
Answer D: "Y" is the main camshaft drive and rotates at crankshaft speed.
 
149. (2.3.5.2-8) The diesel engine rocker arms shown in the illustration serve to Illustration MO-0122
Answer A: convert rotational energy to reciprocating pressures
Answer B: operate the exhaust and starting valves
Correct Answer C: open the exhaust valves and operate the unit injectors
Answer D: open the intake and exhaust valves
150. (2.3.5.2 -9) The rocker arms of the diesel engine shown in the illustration are indicated by . Illustration MO-0122
Correct Answer A: "C" and "Y"
Answer B: "B"
Answer C: "C"
Answer D: "D"
151. (2.3.5.2-11) The injector rack of the diesel engine shown in the illustration is indicated by the component labeled. Illustration MO-0122
Answer A: "B"
Answer B: "E"
Answer C: "F"
Correct Answer D: "G"
 
152. (2.3.5.2-13) Which letter represents the exhaust gas exit point for the diesel engine shown in the illustration? Illustration MO-0122
Answer A: "K"  
Answer B: "J"  
Answer C: "N"  
Correct Answer D: "V"  
153. (2.3.5.2-16) The main lube oil manifold, for the diesel engine shown in the illustration, is represented by the letter or number. Illustration MO-0122
Answer A: "11"
Answer B: "17"
Answer C: "N"
Correct Answer D: "O"
 
154. (2.3.5.2 -4) During the power stroke, the side thrust of a trunk type piston is a result of the angle
Correct Answer A: formed by the connecting rod and the cylinder centerline
Answer B: formed by the piston in relation to the piston pin
Answer C: between the crank arm and crank pin
Answer D: between the master and link connecting rods
 
155. (2.3.5.2 -18) The diesel engine component labeled "1", shown in the illustration is called a/an . Illustration MO-0122
Answer A: external thread
Correct Answer B: exhaust valve spring
Answer C: inlet valve spring
Answer D: conical speed/surge prevention device
156. (2.3.5.2-19) The inlet valves for the diesel engine shown in the illustration are indicated by the letter or number. Illustration MO-0122
Answer A: "2"
Answer B: "19"
Answer C: "H"
Correct Answer D: none of the above are correct
157. (2.3.5.2-21) The diesel engine component labeled "5", shown in the illustration is known as the . Illustration MO-0122
Answer A: heat sink space
Answer B: piston crown
Answer C: connecting rod end assembly
Correct Answer D: piston thrust washer
 
158. (2.3.5.2-24) What is the function of component "13" shown in the illustration? Illustration MO- 122
Answer A: The inlet jumper directs cooling water to the cylinder liner.
Correct Answer B: The device delivers the oil for piston cooling, in addition to liner lubrication.
Answer C: The water pipe is the mechanism in which the 'shaker' method of piston cooling is accomplished.
Answer D: The sample tube monitors the cylinder for evidence of piston blow-by.
159. (2.3.5.2-1) Which of the bearings listed below is most widely used for the main and connecting rod bearings of a modern high-speed diesel engine?
Answer A: Poured babbitt, self-aligning
Answer B: Split roller
Answer C: Steel-lined
Correct Answer D: Precision insert
160. (2.3.5.2-2) Which of the components listed is only found in an opposed-piston engine?
Answer A: Exhaust valves
Answer B: Scavenging ports
Answer C: Combustion chambers
Correct Answer D: Upper and lower crankshafts
 
161. (2.3.6.1-2) Auxiliary diesel engines can be automatically shut down as a result of.
Answer A: low lube oil temperature
Correct Answer B: low lube oil pressure
Answer C: high exhaust temperature
Answer D: high cooling water pressure
 
162. (2.3.6.1-1) Lube oil pumps taking suction from the sump of most small marine engines are usually
Answer A: diaphragm type
Answer B: centrifugal type
Correct Answer C: positive displacement type
Answer D: eductor type
163. (2.3.6.1-3) When a generator diesel engine is operated at partial load, as compared to full load, a decrease will occur in the average.
Answer A: piston speed
Answer B: fuel injection pressure
Correct Answer C: combustion pressure on the power stroke
Answer D: compression pressure on the compression stroke
 
164. (2.3.7.6-1) Intercoolers installed on starting air compressors, reduce the possibility of
Answer A: dust entering the first stage
Correct Answer B: lube oil carbonization
Answer C: discharge pulsations
Answer D: interstage vapor lock
165. (2.3.7.5-2) The cylinders labeled "B" and "C" in the illustration are used to. Illustration MO-0125
Answer A: provide oil to lubricate component "F"
Answer B: supply a specific volume of oil to the engine governor
Answer C: provide the required quantity of grease at specified maintenance intervals
Correct Answer D: supply the force required to shift the engine camshafts axially to reverse engine rotation
166. (2.3.7.5-1) The component labeled "A" on the engine reversing device shown in the illustration, performs its function by transmitting. Illustration MO-0125
Answer A: an electric voltage which energizes solenoids to de-clutch the engine
Answer B: a fuel oil pressure signal which reverses the engine governor control cylinder
Answer C: a hydraulic pressure which shifts an alternate set of camshaft followers to ride on the engine camshaft
Correct Answer D: a pneumatic signal which activates a hydraulic control cylinder allowing the camshaft to shift axially
167. (2.3.7.3 -14) Auxiliary diesel engine electric starting motors use.
Answer A: 400 cycle per second motor-generator power
Correct Answer B: battery power direct current
Answer C: low amperage, high voltage AC power
Answer D: alternating current transformers
168. (2.3.7.3-12) The pinion of an auxiliary diesel-electric starting motor normally engages the flywheel ring gear by means of a/an.
Answer A: automatic follow-up
Answer B: magnetic type coupling
Answer C: muff coupling and release
Correct Answer D: Bendix drive or similar mechanism
169. (2.3.7.3-8) In a Bendix starter drive, the pinion engagement with the flywheel ring gear is initiated by.
Answer A: Bendix spring pressure
Correct Answer B: starter drive shaft rotation
Answer C: a differential spring
Answer D: solenoid throw out action
 
170. (2.3.7.3-2) Which internal combustion engine starting system uses a vane type fluid motor?
Answer A: Jet flow
Correct Answer B: Compressed air
Answer C: Electric
Answer D: Centrifugal
171. (2.3.7.3 -4) Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because.
Answer A: hydraulic starters are the least expensive of all starting systems
Answer B: the system does not require high-pressure piping
Answer C: hydraulic systems turn diesel engines at higher rates of speed than air starters
Correct Answer D: the system can be manually recharged
 
172. (2.3.7.3-7) The purpose of the engine-driven hydraulic pump in an auxiliary diesel engine hydraulic starting system is to.
Correct Answer A: restore hydraulic pressure in the accumulator after starting
Answer B: engage the starter motor with the flywheel
Answer C: fill the sump and prevent low level in the system
Answer D: bypass the hydraulic motor when the engine is running
173. (2.3.7.3-10) Which of the following operating characteristics of the Bendix drive friction clutch is associated with a Bendix drive starter?
Correct Answer A: Helps absorb the shock when the pinion engages the flywheel ring gear.
Answer B: Disengages the pinion from the flywheel ring gear.
Answer C: Engages the pinion with the air start distributor.
Answer D: Prevents the pinion starter from overrunning on the starter shaft.
 
174. (2.3.7.3-1 1) A Bendix drive starting motor disengages the drive gear from the flywheel by
Answer A: spring force
Correct Answer B: having the flywheel impart a torque to the starter pinion
Answer C: rotation of the starting cam
Answer D: applying accumulator pressure
175. (2.3.7.3-9) In a diesel engine starting motor equipped with a Bendix drive, the pinion moves and meshes with the flywheel ring gear due to.
Correct Answer A: the shaft sleeve spiral helix and relative rotation between pinion and starter shaft
Answer B: shifting levers of solid mechanical linkage
Answer C: centrifugal force developed from rotation
Answer D: electromotive force developed at the flywheel
176. (2.3.7.3-15) Diesel engine electric starting motors generally require heavier duty motors and operate at higher voltages than comparable starting motors for gasoline engines due to
Answer A: higher speed required
Answer B: lower starting temperatures
Correct Answer C: higher compression pressures
Answer D: flywheel effect
 
177. (2.3.7.3-13) Electric starting motors for diesel engines require high current for operation and
Answer A: require a generator as a source of power
Correct Answer B: will carry a 100% overload for a brief period
Answer C: require a current/voltage regulator for proper operation
Answer D: will overheat if operated continuously over 10 seconds
 
178. (2.3.7.3-5) Which type of starter motor is normally used in a diesel engine hydraulic starting system?
Correct Answer A: Axial piston
Answer B: Centrifugal
Answer C: Precision gear
Answer D: Turbine drive
179. (2.3.7.3-1) Air motors used for starting some auxiliary diesel engines are generally the type known as a/an.
Answer A: accumulator motors
Correct Answer B: vane motors
Answer C: gear motors
Answer D: plunger motors
180. (2.3.7.3-3) The illustration is of a/an. Illustration MO-0044
Correct Answer A: air driven starter motor assembly
Answer B: power take-off driven, vane type, air compressor
Answer C: air driven DC generator
Answer D: battery powered, electric motor driven vane type, hydraulic pump
 
181. (2.3.7.3-6) When an engine fitted with a hydraulic starting system starts up, the starter is protected from the higher speed of the engine by.
Answer A: the immediate increase in hydraulic pressure
Correct Answer B: the overrunning clutch
Answer C: closing the starting check valves
Answer D: the pivoting of the shaft from being engaged with the flywheel
 
182. (2.3.7.2-4) During the starting of a diesel engine, compression gases are prevented from backing into the air starting system, shown in the illustration, by the. Illustration MO-0046
Correct Answer A: cylinder air starting check valves
Answer B: individual distribution valves
Answer C: high-pressure in the starting air manifold
Answer D: air starting control valve
 
183. (2.3.7.2-2) Which of the following statements is true concerning the air starting valve, labeled ''IN'', as shown in the illustration? Illustration MO-0046
Answer A: During normal engine running, the air starting valve opens and closes constantly due to cam action.
Correct Answer B: The air starting valve is opened by cam action.
Answer C: When starting air is secured, the air starting valve is closed.
Answer D: When starting, the air starting valve is held open by air pressure.
 
184. (2.3.7.2-3) The pilot valves in an air pilot starting system for a two-stroke cycle, direct reversing, main propulsion diesel engine are operated by either a ported distributor disc or a/an.
Answer A: regulator valve
Answer B: quick opening main air valve
Answer C: pilot air start check valve
Correct Answer D: individual cam for each pilot valve
 
185. (2.3.7.2-5) A six-cylinder, four-stroke cycle diesel engine is fitted with a rotary distributor type air starting system. The speed of the rotating distributor disc is.
Correct Answer A: one-half engine speed
Answer B: the same as engine speed
Answer C: twice engine speed
Answer D: four times engine speed
 
186. (2.3.7.2-1) Starting systems for large, direct reversing, main propulsion diesel engines are usually
Answer A: hydraulic starting motors
Answer B: electric starting motors
Correct Answer C: direct air admission
Answer D: vane type air motors
 
187. (2.3.7.2-6) In a direct cylinder admission air starting system, once the engine begins to fire, the air starting check valve illustrated, is closed by. Illustration MO-0107
Answer A: the starting air pressure
Correct Answer B: the spring force and cylinder pressure
Answer C: a valve actuating cam
Answer D: a pneumatic bellows assembly
 
188. (2.3.7.2-7) When an air started, four-stroke cycle diesel engine is being cranked over, the starting air is admitted to each cylinder during the beginning of its.
Answer A: intake stroke
Answer B: compression stroke
Correct Answer C: power stroke
Answer D: exhaust stroke
189. (2.3.7.2-8) In a medium-speed marine propulsion engine equipped with direct admission air starting valves, the cylinders without air starting valves fire first because the.
Answer A: operation is under higher compression
Answer B: fuel is admitted only to these cylinders during cranking
Answer C: compression is released during starting by opening the exhaust valve
Correct Answer D: cylinders are not chilled by the expansion of the starting air
190. (2.3.7.4-1) An oil-operated, direct reversing mechanism on a large, low-speed, main propulsion diesel engine, can serve to.
Answer A: bring the respective cam under the air distributor pilot valves
Answer B: bring the respective cam under the fuel pump roller
Answer C: rotate or displace the camshaft according to engine design
Correct Answer D: all of the above
 
191. (2.3.7.4-2) In order to reverse the rotation of a two-stroke cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the .
Correct Answer A: starting air and fuel pumps
Answer B: piston cooling pumps
Answer C: exhaust valves
Answer D: all of the above
 
192. (2.3.7.1-5) In addition to the main starting air compressor, another air compressor, driven by a separate power source, is installed to.
Answer A: provide air for engine scavenging
Answer B: provide air for engine supercharging
Correct Answer C: supply a backup source of starting air
Answer D: supply the independent source of reversing air
 
193. (2.3.7.1-1) Starting a large low-speed propulsion diesel engine on diesel fuel during cold weather conditions will be made easier by.
Answer A: increasing the quantity of starting air
Answer B: increasing the lube oil pressure
Answer C: heating the engine fuel supply
Correct Answer D: heating the engine coolant
194. (2.3.7.1-9) Which of the listed diesel engine starting systems is most susceptible to difficulties in cold weather?
Answer A: Direct cylinder admission air start
Answer B: Hydraulic
Correct Answer C: Electric
Answer D: Air motor starting
195. (2.3.7.1-8) An accumulator used in a hydraulic starting system is generally located between the
Answer A: pump and the compressor
Answer B: storage tank and the pump
Answer C: starting motor and the reserve tank
Correct Answer D: pump and the starting motor
196. (2.3.7.1-2) Which of the routine maintenance procedures listed is required for starting air receivers?
Correct Answer A: Frequent draining of accumulated moisture.
Answer B: Frequent testing of relief valves.
Answer C: A close watch on temperature to prevent fluctuations in pressure.
Answer D: Frequent cleaning to remove oil and foreign matter.
197. (2.3.7.1-3) When starting a diesel engine at temperatures below 70F, the frictional resistance to turning will be.
Answer A: reduced by increasing lube oil pressure
Answer B: controlled by reducing the compression ratio
Correct Answer C: proportional to the lube oil viscosity
Answer D: eliminated by heating the intake air
 
198. (2.3.7.1-7) A two-stroke cycle diesel engine requires less starting air than a four-stroke cycle diesel engine, of equal displacement, because the two-stroke cycle diesel engine.
Answer A: has little or no internal friction
Answer B: has a lower effective compression ratio
Answer C: operates with scavenge air under a positive pressure
Correct Answer D: operates without energy absorbing intake and exhaust strokes
 
199. (2.3.7.1-4) Starting air check valves are held firmly on their seats by.
Answer A: cam rollers on the camshaft
Correct Answer B: spring force
Answer C: air pressure on top of the valve differential piston
Answer D: air pressure on the bottom of the valve differential piston
200. (2.3.8.9-4) A decrease in the flash point of diesel engine lube oil indicates the lube oil has become.
Answer A: contaminated with sludge
Answer B: contaminated with carbon
Correct Answer C: diluted with fuel oil
Answer D: diluted with water
 
201. (2.3.8.9 -2) Which of the following test indicators should be considered the most significant factor in determining as to whether or not a diesel-generator's lube oil should be drained and renewed?
Correct Answer A: An extremely high neutralization number.
Answer B: An extremely low precipitation number.
Answer C: The oil appears black in color.
Answer D: An increase in flash point.
 
202. (2.3.8.9-1) A 'Blotter test' is a test performed on the lube oil of a diesel engine which can determine.
Answer A: the specific gravity of the oil
Answer B: the flash point of the oil
Correct Answer C: a change in the oils viscosity
Answer D: the TBN number of the oil
203. (2.3.8.9-3) If the analysis of used lube oil indicates a high content of iron particles, this could indicate.
Answer A: corrosive deterioration of a bearing
Answer B: inadequate air filtration
Correct Answer C: excessive ring and liner wear
Answer D: excessive cooling of lubricating oil
 
204. (2.3.8.2 -4) A magnetic strainer is primarily used in diesel engine reduction gear oil systems to remove small particles of.
Answer A: copper
Answer B: babbitt
Correct Answer C: ferrous materials
Answer D: acidic materials
 
205. (2.3.8.2-6) How is the illustrated strainer element cleaned during engine operation? Illustration MO-0057
Answer A: The drain plug is removed and the housing is drained.
Answer B: The housing is removed and the element is cleaned with a solvent.
Correct Answer C: The T-handle is rotated.
Answer D: The strainer element is removed, cleaned in kerosene or solvent, and dried with an air brush.
 
206. (2.3.8.2-1) A spring-loaded relief valve is located on some lube oil filters in full flow systems to
Answer A: prevent overpressurization of the filter cartridge
Answer B: prevent overpressurization of the filter casing
Correct Answer C: bypass the filter should it become clogged
Answer D: limit the lube oil outlet pressure
207. (2.3.8.2-3) Most large main propulsion diesel engines use a duplex lube oil strainer to
Answer A: decrease the time required between cleanings
Answer B: remove all large and small foreign objects
Correct Answer C: ensure a positive flow of oil at all times
Answer D: ensure that all lube oil has been treated twice
208. (2.3.8.2-5) Where would a coarse screen wire mesh strainer normally be found on a diesel engine lubrication system?
Answer A: pump discharge line
Answer B: gravity tank inlet line
Answer C: filter bypass return line
Correct Answer D: pump suction line
 
209. (2.3.8.8-4) Wrist pin bearings are difficult to lubricate because of their oscillating motion and
Answer A: their free-floating design
Answer B: their relatively small size
Answer C: the reciprocating motion of the piston
Correct Answer D: their position in the lubrication system
 
210. (2.3.8.8 -3) The upper piston rings in large, slow-speed, two-stroke cycle diesel engines are most effectively lubricated by oil.
Correct Answer A: fed from mechanical lubricators
Answer B: thrown off from the main bearings
Answer C: supplied from wick fed drip lubricators
Answer D: flow from a centrifugal or banjo oiler
211. (2.3.8.8-2) Shaker, circulation, and spray are the three general methods used in.
Answer A: pre-injection fuel oil treatment
Answer B: lube oil filtration
Answer C: lube oil purification
Correct Answer D: piston cooling
212. (2.3.8.8 -1) For diesel engine piston cooling, lubricating oil can be supplied to the pistons by a/an
Correct Answer A: oil spray
Answer B: oil wick
Answer C: oil control rings
Answer D: drilled passage through the camshaft
 
213. (2.3.8.1-12) Proper lubrication of the main bearings is more easily obtained in a single acting four- stroke cycle diesel engine than in a single acting two-stroke cycle diesel engine because
Correct Answer A: bearing pressure in a four-stroke cycle single acting diesel engine is continually reversed
Answer B: bearing pressure in a two-stroke cycle single acting diesel engine is continually reversed
Answer C: the maximum bearing pressure is higher in a single acting two-stroke cycle diesel engine
Answer D: two-stroke cycle diesel engines require more complicated lubrication piping
 
214. (2.3.8.1 -4) A diesel engine exposed to widely varying ambient temperatures should use a lubricating oil with.
Correct Answer A: a high viscosity index
Answer B: a low viscosity index
Answer C: extreme pressure additives
Answer D: no additives
 
215. (2.3.8.1-17) In a normally operating diesel engine, the main source of lubricating oil contamination in the crankcase is a result of the.
Answer A: metal particles loosened by wear
Answer B: air when no air cleaners are used
Answer C: condensation of water vapors
Correct Answer D: combustion by-products removed from the cylinder walls
216. (2.3.8.1-13) Lube oil filters remove contaminants more efficiently if the oil being filtered is
Answer A: under high-pressure
Answer B: under low-pressure
Correct Answer C: heated to reduce viscosity
Answer D: cooled to increase viscosity
217. (2.3.8.1-1 1) A well-lubricated bearing surface always appears
Answer A: well knurled
Answer B: slightly streaked
Answer C: lightly glazed
Correct Answer D: highly polished
 
218. (2.3.8.1-6) A diesel engine should use which type of lubricating oil?
Answer A: Low viscosity
Answer B: Cutting oil
Answer C: High grade vegetable oil
Correct Answer D: Detergent oil
219. (2.3.8.1-7) The highest indicated lube oil pressure in a diesel engine should be expected when the engine oil is.
Correct Answer A: cold at idle
Answer B: warm at idle
Answer C: warm at full speed
Answer D: warm at full speed and no fuel dilution exists
 
220. (2.3.8.1 -15) Which of the listed diesel engine operating conditions should be checked immediately after any diesel engine is started?
Answer A: Exhaust temperature
Answer B: Lube oil level
Correct Answer C: Lube oil pressure
Answer D: Water level in the expansion tank
 
221. (2.3.8.1-1) According to the diagram shown in the illustration, the lube oil system can best be described as a. Illustration MO-0007
Answer A: bypass system
Answer B: dry sump system
Correct Answer C: wet sump system
Answer D: shunt system
 
222. (2.3.8.1-16) The most crucial time for any bearing with regards to diesel engine lubrication is
Answer A: during periods of low load
Answer B: during first warm up
Correct Answer C: during initial starting
Answer D: after load reversals
223. (2.3.8.1-19) How often should the lubricating oil of a diesel engine be changed?
Answer A: After every trip
Answer B: Every 4000 hours
Correct Answer C: According to manufacturer's instructions
Answer D: Every time they are shutdown
 
224. (2.3.8.1-2) Which of the following devices is normally provided to prevent oil starvation in a diesel engine lubrication system utilizing the 'full flow' principle?
Answer A: Duplex strainer
Answer B: Three-way valve
Correct Answer C: Pressure relief bypass line around the filter
Answer D: Mechanical straining filter
 
225. (2.3.8.1-5) Two important considerations for the proper lubrication of a diesel engine include, the delivery of the oil in sufficient amount, and the .
Answer A: cetane number
Answer B: pour point
Answer C: viscosity temperature
Correct Answer D: quality of the oil
226. (2.3.8.1-8) The TBN value of diesel engine lube oil refers to its ability to.
Answer A: resist changes in viscosity with changes in temperature
Answer B: resist emulsification
Correct Answer C: neutralize acids
Answer D: resist oxidation at high temperatures
227. (2.3.8.1-3) The lube oil pump used in a diesel engine is normally a.
Answer A: volute pump
Answer B: centrifugal pump
Answer C: diaphragm pump
Correct Answer D: gear pump
228. (2.3.8.1-14) Which of the following should always be checked prior to starting a diesel engine?
Answer A: Air filters
Answer B: Fuel oil strainers
Correct Answer C: Crankcase oil level
Answer D: Pyrometer readings
 
229. (2.3.8.1-9) Which lubricating oil additive is used in diesel engines to reduce the tendency for sludge and varnish to form on the engine parts?
Answer A: Flash point improvers
Answer B: Pour point improvers
Correct Answer C: Inhibitors
Answer D: Foam suppressors
 
230. (2.3.8.1-10) On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by.
Answer A: banjo feed
Answer B: splash feed
Answer C: gravity feed
Correct Answer D: pressure feed
231. (2.3.8.1-18) Before starting a diesel engine that has an engine driven lube oil pump, the operator should.
Answer A: open the bypass line
Answer B: cut in the lube oil cooler
Correct Answer C: pressurize the lube oil system with the prelube pump
Answer D: top off the expansion tank
232. (2.3.8.3-1) What type of engine lubrication oil filter system sends filtered oil directly to the high- pressure supply gallery?
Answer A: centrifugal purifier system
Answer B: bypass system
Correct Answer C: shunt system
Answer D: batch system
 
233. (2.3.8.3-2) In a bypass type lubrication system for a diesel engine, the dirty oil line to the centrifuge should be taken from the.
Answer A: lube oil pump suction line
Answer B: lube oil pump discharge line
Correct Answer C: bottom of the lube oil sump
Answer D: outlet from the lube oil header
234. (2.3.8.5-2) Which of the following statements is true concerning a main diesel engine oil cooler?
Answer A: The oil temperature is less than the cooling water temperature.
Answer B: The oil pressure is less than the cooling water pressure.
Correct Answer C: The oil pressure is greater than the cooling water pressure.
Answer D: The oil flow control valve is always installed in the oil input line.
235. (2.3.8.5-4) Reduction gear lube oil temperatures for keel cooler installations are generally
Answer A: lower than raw water cooled installations
Correct Answer B: higher than raw water cooled installations
Answer C: identical to raw water cooled installations
Answer D: lower than raw water cooled installations, but the pressure will be higher
 
236. (2.3.8.5-3) Heat exchangers are most commonly found in a small auxiliary diesel engine
Answer A: fuel oil system
Answer B: governing system
Answer C: air starting system
Correct Answer D: lube oil system
237. (2.3.8.5-1) The lube oil cooler is located after the lube oil filter in order for.
Correct Answer A: the filter to operate more efficiently
Answer B: the lube oil cooler to be bypassed
Answer C: positive lube oil pump suction to be assured
Answer D: galvanic action in the cooler to be minimized
238. (2.3.8.4-1) Maximum lube system operating pressure for a diesel engine is normally regulated by a/an.
Answer A: orifice in the pump suction
Answer B: special filter design
Answer C: pressure drop through the filter
Correct Answer D: relief valve
239. (2.3.8.6-5) The illustrated device is used to. Illustration MO-0050
Correct Answer A: supply cylinder lubricating oil to the engine
Answer B: meter fuel oil to the injectors
Answer C: admit the correct amount of starting air to the cylinders in proper order
Answer D: actuate exhaust valves in the correct sequence
 
240. (2.3.8.6 -6) The component labeled as part No.20 in the illustration is used to . Illustration MO-0050
Answer A: meter the amount of oil flow to the cylinder lubricating quill
Answer B: adjust the timing of the cylinder lubricating oil to the cylinder
Correct Answer C: indicate the quantity of oil flow to the cylinder
Answer D: prevent the backflow of oil and combustion gases
241. (2.3.8.6-7) The adverse effects of burning high sulfur fuel can be compensated for by using a cylinder oil having sufficient.
Answer A: dispersant additives
Answer B: floc point depressive additives
Correct Answer C: alkalinity
Answer D: ignition quality
 
242. (2.3.8.6-2) Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are.
Answer A: operated manually once each hour
Answer B: operated until the engine has started
Answer C: placed into operation only at maximum load
Correct Answer D: adjustable to meet lubrication requirements
 
243. (2.3.8.6-1) One advantage of a vacuum feed sight glass indicator used on cylinder lubricators over the discharge side liquid filled type sight glass is.
Answer A: there are fewer moving parts
Answer B: adjustments are not required
Correct Answer C: better visual metering adjustment
Answer D: a lower grade of cylinder oil may be used
244. (2.3.8.6 -3) The rate of cylinder lubricating oil metered to each cylinder of a large, low-speed, main propulsion diesel engine is.
Answer A: the same, whether at sea, or during maneuvering
Answer B: adjusted during each hour of operation while at constant RPM
Correct Answer C: reduced during periods of low load operation
Answer D: lower at sea than while maneuvering
 
245. (2.3.8.6-4) The device shown in figure "A" of the illustration is used to. Illustration MO-0042
Answer A: inject fuel into the cylinder
Answer B: admit starting air to the cylinder
Correct Answer C: provide lubrication to the cylinder
Answer D: provide an adapter to obtain combustion pressure readings
246. (2.3.8.7-1) The device shown in the illustration is classified as a/an. Illustration MO- 0008
Correct Answer A: comparator type mist detector
Answer B: exhaust gas vapor condenser
Answer C: Ringelmann exhaust gas analyzer
Answer D: reflective type explosion meter
 
247. (2.3.8.7-2) The device shown in the illustration is a. Illustration MO-0008
Answer A: rotary type mist detector, designed for use in four-stroke, high-speed diesel engines
Answer B: photoelectric, explosive gas indicator, for use in high-speed, two-stroke, trunk type piston engines
Correct Answer C: comparator type mist detector for large low-speed, crosshead type engines
Answer D: level type explosimeter, for small medium-speed, trunk type piston engines
248. (2.3.8.7-5) Crankcase explosions in propulsion diesel engines result from.
Answer A: the splashing of lubrication oil by the crankshaft
Answer B: the dilution of crankcase oil with particles of combustion
Answer C: broken fuel lines spraying oil on the crankcase
Correct Answer D: the ignition of unburned fuel and air in the crankcase
249. (2.3.8.7-3) The purpose of an oil mist detector in a main propulsion diesel engine is to warn of
Correct Answer A: a possible overheated bearing
Answer B: excessively high crankcase vacuum
Answer C: low cylinder oil pressure
Answer D: excessive carbon buildup in the lube oil
250. (2.3.8.7-4) Which of the following problems could develop due to the accumulation of oil vapors in the crankcase of a diesel engine?
Answer A: Reduced lubrication
Answer B: Poor fuel economy
Answer C: Combustion knock
Correct Answer D: Crankcase explosion
 
251. (2.3.9.1.1-1) Starting aids such as glow plugs, are installed on.
Answer A: large, direct drive diesel engines
Answer B: diesel engines designed to burn residual fuels
Answer C: medium-speed, four-stroke cycle diesel engines
Correct Answer D: small diesel engines utilizing electric starting equipment
252. (2.3.9.1.1-2) Precombustion chambers and energy cells in high-speed, small bore diesel engines all serve to increase.
Answer A: firing pressure
Answer B: ignition quality of fuel
Answer C: fuel/air ratio during compression
Correct Answer D: turbulence
253. (2.3.9.1.1-3) Which of the combustion chambers shown in the illustration is referred to as an "energy cell" used in some small diesel engines? Illustration MO-0068
Correct Answer A: A
Answer B: B
Answer C: C
Answer D: D
 
254. (2.3.9.1.1 -4) The purpose of the energy cell, or air cell, is to.
Answer A: cause auto-ignition in the cell rather than in the main combustion chamber
Correct Answer B: create a high turbulence within the main combustion chamber
Answer C: allow the spray to hit the piston rim rather than the cooler cylinder wall
Answer D: make a blast in the main chamber prior to the piston expansion stroke
255. (2.3.9.1.2-1) A multi-orifice fuel injection nozzle is usually used with which of the listed types of combustion chamber?
Correct Answer A: Open combustion chamber
Answer B: Precombustion chamber
Answer C: Turbulence chamber
Answer D: Energy cell
 
256. (2.3.9.1.2-2) Open combustion chambers are designed to.
Answer A: eliminate carbon buildup
Answer B: improve piston cooling
Answer C: prevent air charge turbulence
Correct Answer D: provide proper fuel/air mixing
 
257. (2.3.9.1.2-3) What type of marine engine has a fuel nozzle and combustion chamber located between two pistons in a common cylinder liner?
Answer A: Horizontal reciprocating
Correct Answer B: Vertical opposed-piston
Answer C: Single acting in-line cylinder
Answer D: Double acting in-line cylinder
 
258. (2.3.9.1.2-4) A diesel engine with a combustion chamber located between the crowns of two pistons is known as a/an.
Answer A: double-acting engine
Correct Answer B: opposed-piston engine
Answer C: single-acting engine
Answer D: horizontal acting engine
259. (2.3.9.1.3-1) Precombustion chambers differ from turbulence chambers in that precombustion chambers.
Answer A: allow fuel injection directly into the space above the piston
Answer B: do not contain the fuel injector nozzle tip
Answer C: contain the major portion of the total clearance volume
Correct Answer D: contain a smaller portion of the total clearance volume
260. (2.3.9.1.4-1) Starting aids, such as glow plugs, are usually installed on.
Answer A: large, direct drive diesel engines
Answer B: diesel engines designed to burn residual fuels
Answer C: medium-speed, four-stroke cycle diesel engines
Correct Answer D: small diesel engines with electric motor starters
 
261. (2.3.9.1.5-1) The combustion of fuel for the illustrated engine is initiated by. Illustration MO-0020
Answer A: fuel injection provided by a unit injector
Answer B: individual Bosch fuel pumps
Correct Answer C: a spray of fuel into a turbulence combustion chamber
Answer D: fuel sprayed into an energy cell
 
262. (2.3.9.1.5-2) Which of the listed types of precombustion chambers is used in the diesel engine shown in the illustration? Illustration MO-0007
Correct Answer A: Turbulence chamber
Answer B: Energy cell
Answer C: Common rail
Answer D: Open type
 
263. (2.3.9.2.1-1) The desirable properties of a marine fuel oil should include.
Answer A: low heating value and high sulfur content
Answer B: low flash point and high viscosity
Answer C: high flash point and high viscosity
Correct Answer D: high heating value and low sulfur content
 
264. (2.3.9.2.2-1) With respect to diesel fuel, the ease with which a cold engine will start is dependent upon the.
Correct Answer A: ignition quality of the fuel
Answer B: high heating value of the fuel
Answer C: amount of carbon residue after combustion
Answer D: internal flow resistance in the injectors
 
265. (2.3.9.2.2 -2) The ignition quality of diesel fuel becomes LESS critical as.
Answer A: lube oil additives are increased
Answer B: designed piston speeds are increased
Answer C: designed injection pressures are decreased
Correct Answer D: designed engine speeds are decreased
266. (2.3.9.2.2-3) The cetane number rates fuels for diesel engines according to its .
Answer A: antiknock characteristics
Correct Answer B: ignition qualities
Answer C: rates of vaporization
Answer D: viscosity
267. (2.3.9.2.2-4) Which of the following statements is true concerning the cetane number of diesel fuel?
Answer A: The cetane number affects the amount of injection lag.
Answer B: The cetane number is an indication of the fuel's viscosity.
Correct Answer C: Ignition lag is reduced with fuels having a high cetane number.
Answer D: The cetane number is of little significance in the combustion process.
 
268. (2.3.9.2.2-5) A mixture of 45% cetane and 55% alpha-methyl-naphthalene is found to have the same ignition delay as a sample of diesel oil. The sample can be described as having a/an
Answer A: cetane number of 55
Correct Answer B: cetane number of 45
Answer C: octane number of 55
Answer D: octane number of 45
 
269. (2.3.9.2.3-1) If a particular liquid has a specific gravity of 0.96 kg/dm3 at 77F, what will be the specific gravity of the liquid, as determined from the graph shown in the illustration, if the temperature is increased to 167F? Illustration MO-0113
Answer A: 0.910 kg/dm3
Answer B: 0.915 kg/dm3
Answer C: 0.920 kg/dm3
Correct Answer D: 0.925 kg/dm3
 
270. (2.3.10.2.1-1) For optimum results, centrifugal purification of heavy fuel oil should be accomplished with the fuel at the lowest practicable .
Correct Answer A: throughput
Answer B: additive percent
Answer C: cetane number
Answer D: TBN number
271. (2.3.10.2.1-3) Which factor determines the size of the ring dam for a fuel oil centrifugal purifier?
Answer A: Viscosity of the fuel.
Answer B: Quantity of water to be removed from the fuel.
Correct Answer C: Specific gravity of the fuel.
Answer D: Quantity of dirt to be removed from the fuel.
 
272. (2.3.10.2.1-2) Which of the listed substances can be satisfactorily removed from diesel fuel by centrifuging?
Correct Answer A: Sludge
Answer B: Gasoline
Answer C: Fuel oil
Answer D: Lube oil
273. (2.3.10.2.1-4) Whether using a centrifuge or a simple filter, oil cleaning and filtration will be the most effective when the oil is at a.
Answer A: high temperature and a high viscosity
Correct Answer B: high temperature and a low viscosity
Answer C: low temperature and a high viscosity
Answer D: low temperature and a low viscosity
 
274. (2.3.10.2.3-4) The device labeled "D", as shown in the illustration, is the bowl_ Illustration MO-0112
Answer A: hood
Correct Answer B: top
Answer C: cover
Answer D: hub
275. (2.3.10.2.3-13) The discharge nozzle shown in the illustration, is indicated by the letter . Illustration MO-0112
Answer A: A
Answer B: K
Correct Answer C: S
Answer D: X
 
276. (2.3.10.2.3-3) The device labeled "B", shown in the illustration is known as the Illustration MO-0112
Answer A: upper ring chamber
Answer B: set of regulating rings
Answer C: comminuting device
Correct Answer D: centripetal pump chamber cover
 
277. (2.3.10.2.3-9) The area indicated by the letter "L" of the device shown in the illustration is properly called the. Illustration MO-0112
Answer A: pre-injection chamber
Answer B: operating water reservoir
Answer C: channeling chamber
Correct Answer D: injection chamber
 
278. (2.3.10.2.3-19) The unit shown in the illustration is beginning the sludge discharge cycle. The operating liquid solenoid valve has been energized and space "J" is filling up. Which of the following actions should occur next? Illustration MO-0112
Answer A: The liquid enters the opening space, controlled by the discharge port "S", thereby causing the sliding bowl bottom to move upwards.
Correct Answer B: The liquid enters via port "X" into the opening space with the net resultant force causing the piston slide to move down.
Answer C: The liquid enters via port "X", travels through the closing chamber, and exits port "S", maintaining an upward force against the bowl bottom.
Answer D: The liquid remains trapped in space "J", developing an upward force to open the bowl.
 
279. (2.3.10.2.3-14) The gasket "U" shown in the illustration, is used to seal the liquid space below the . Illustration MO-0112
Answer A: ring dam
Answer B: inner bowl
Answer C: outer bowl
Correct Answer D: sliding piston
 
280. (2.3.10.2.3-6) The device labeled "H", shown in the illustration is referred to as the. Illustration MO-0112
Answer A: upper chamber bowl gasket
Correct Answer B: centrifugation chamber bottom gasket
Answer C: sliding piston upper seal
Answer D: sliding piston lower seal
 
281. (2.3.10.2.3-2) The device labeled 'C' shown in the illustration is known as the. Illustration MO-0112
Correct Answer A: upper locking ring
Answer B: lower paring device
Answer C: upper paring gasket
Answer D: pump lock
 
282. (2.3.10.2.3-18) Where does the shoot cycle operating liquid first come in contact with the rotating forces of the device shown in the illustration? Illustration MO-0112
Answer A: While traveling under disc stack "N".
Answer B: At the inlet cone labeled "O".
Correct Answer C: In the opening chamber labeled "L".
Answer D: At the inlet orifice labeled "S".
283. (2.3.10.2.3-17) What is used as the primary operating medium during the sludge discharge cycle, shown in the illustration? Illustration MO-0112
Answer A: Light phase liquid
Answer B: Heavy phase liquid
Answer C: Hydraulic fluid
Correct Answer D: Water
 
284. (2.3.10.2.3-5) The item indicated by the letter "F" of the device shown in the illustration is the . Illustration MO-0112
Answer A: guide band
Answer B: guide pin
Answer C: locating dowel pin
Correct Answer D: upper bowl gasket
285. (2.3.10.2.3-20) What terminates the sludge discharge cycle of the device shown in the illustration? Illustration MO-0112
Answer A: The solenoid valve opens, directs high-pressure fluid into the closing chamber, and results in an upward movement of the sliding piston.
Answer B: The solenoid valve closes, reduces the water pressure to the paring chamber, and allows the spring force to move the sliding piston upward.
Correct Answer C: The solenoid valve closes, allows the water in the opening chamber to bleed off through "S", and the sliding piston moves upward due to the force developed in area "J".
Answer D: The solenoid valve closes, allows the weight of the sliding piston to oppose the low water pressure, and moves it along the axis of the spindle.
286. (2.3.10.2.3-15) The port "X" shown in the illustration allows water to enter the adjoining chamber. During what cycle of operation will this occur? Illustration MO-0112
Answer A: Operating backflush cycle
Answer B: Bowl retention cycle
Answer C: Clarification cycle
Correct Answer D: Sludge discharge cycle
287. (2.3.10.2.3-12) The wear liner shown in the illustration is indicated by the letter. Illustration MO-0112
Answer A: "G"
Answer B: "N"
Answer C: "P"
Correct Answer D: "R"
 
288. (2.3.10.2.3-7) The force developed by the liquid within space "J" of the device shown in the illustration depends upon. Illustration MO-0112
Answer A: the speed of the bowl and the condition of seal "H"
Answer B: the angular velocity at which the liquid travels
Correct Answer C: the speed of the bowl and the condition of seal "U"
Answer D: inertia forces during starting and stopping
 
289. (2.3.10.2.3-16) The area indicated by the letter "W", shown in the illustration is correctly termed the. Illustration MO-0112
Answer A: closing chamber
Answer B: parting chamber
Answer C: upper sliding piston chamber
Correct Answer D: opening chamber
 
290. (2.3.10.2.3-1) The device labeled "A", shown in the illustration, is known as the. Illustration MO-0112
Answer A: centripetal pump cover
Answer B: bowl assembly hood
Correct Answer C: regulating ring
Answer D: kinetic converter
 
291. (2.3.10.2.3-8) During normal operation, the liquid retained in space 'J' of the device shown in the illustration is. Illustration MO-0112
Correct Answer A: directly forcing the sliding piston upward to keep the bowl closed
Answer B: maintaining the bowl oil/water seal interface
Answer C: lubricating the shaft bearings
Answer D: maintaining oil pump pressure
292. (2.3.10.2.3-11) Item "O" of the device shown in the illustration is the. Illustration MO-0112
Answer A: fair flow nut
Answer B: inlet directional guide
Correct Answer C: spindle nut
Answer D: impeller locking device
293. (2.3.10.2.3-10) Which of the following statements describes "N" shown in the illustration? Illustration MO-0112
Answer A: the included angle of oil flow
Correct Answer B: the centrifuge disc stack
Answer C: the sole direction of heavy phase flow
Answer D: the relative size of the separation zone
 
294. (2.3.10.2.3-21) During the normal operation of the centrifuge shown in the illustration, the operating liquid solenoid and bypass valves for the cleaning cycle should be in which position? Illustration MO-0112
Answer A: The solenoid valve is closed and the bypass valve is open.
Correct Answer B: The solenoid valve is closed and the bypass valve is closed.
Answer C: The solenoid valve is open and the bypass valve is closed.
Answer D: The solenoid valve is open and the bypass valve is open.
 
295. (2.3.10.5-3) For a continuous operation diesel engine, a duplex filter unit would be the best arrangement because.
Correct Answer A: changing filter elements would not interrupt engine operation
Answer B: filtering occurs twice in each pass of oil through the system
Answer C: clogging will not occur
Answer D: dropping pressure is half of that through a single filter unit
296. (2.3.10.5-2) To minimize corrosion, fuel oil strainer disks, spacers and scraper blades are made of.
Answer A: brass
Answer B: copper
Answer C: iron
Correct Answer D: monel metal or stainless steel
 
297. (2.3.10.2.2-5) Which of the following precautions should be taken prior to starting the separator shown in the illustration? Illustration MO-0127
Answer A: Make sure the separator is properly assembled.
Answer B: Check for the correct oil level in the gear housing.
Answer C: Release the bowl brake and confirm proper valve line up.
Correct Answer D: All of the above are correct.
298. (2.3.10.2.2-2) The device shown in the illustration can be automatically or manually desludged. The closing sequence at the end of the desludging cycle is initiated by opening which of the labeled components listed below? Illustration MO-0012
Answer A: F
Answer B: P
Correct Answer C: Q
Answer D: R
 
299. (2.3.10.2.2-4) Which of the labeled figures illustrated, represents the correct alignment mark relationships of a properly reassembled centrifuge bowl? Illustration MO-0022
Correct Answer A: A
Answer B: B
Answer C: C
Answer D: D
 
300. (2.3.10.2.2-9) In the device shown in the illustration, the component lettered "A" is the . Illustration MO-0012
Answer A: seal water input port
Answer B: heavy phase discharge port
Answer C: light phase discharge port
Correct Answer D: dirty oil input port
301. (2.3.10.2.2-6) How is oil supplied to the device shown in the illustration? Illustration MO-0127
Answer A: An attached positive displacement pump supplies oil to the separator.
Correct Answer B: In this arrangement an independent pump is utilized.
Answer C: The oil inlet paring disc creates a low-pressure in the suction piping.
Answer D: This purifier as well as most others will be installed in the lower engine room to make use of gravitational forces.
302. (2.3.10.2.2-12) Which of the following statements represents the working principle of the water transducer used with the separator shown in the illustration? Illustration MO-0127
Answer A: The capacitor completes part of the inductive circuit which monitors pressure changes.
Correct Answer B: The probe and sensor measure the dielectric constant through capacitive reactance of the process fluid.
Answer C: As the water content in the oil decreases, the dielectric constant increases.
Answer D: All of the above are correct.
 
303. (2.3.10.2.2-7) Which of the following statements is accurate concerning the vibration sensing device used with the separator shown in the illustration? Illustration MO-0127
Answer A: Vibration sensors are not used with centrifuges currently installed on diesel vessels due to excessive vibrations developed by the main propulsion units.
Answer B: The vibration switch is sensitive to vibration in a direction horizontal to its mounting base and is normally installed low on the separator where movement is magnified.
Correct Answer C: The detector mechanism consists of an armature suspended on a flexure pivot and restrained from motion by a permanent magnet acting through a small air gap.
Answer D: The detector is so arranged to prevent abnormal harmonic frequencies from being developed while the separator is passing through its critical speed range.
 
304. (2.3.10.2.2-1) The temperature of the contaminated fuel oil fed to the centrifuge shown in the illustration should be. Illustration MO-0012
Answer A: 160F to 180F
Correct Answer B: 203F to less than 212F
Answer C: greater than 212F
Answer D: selected according to the oil's viscosity index
 
305. (2.3.10.2.2-10) All alarms occurring on the control unit of the device shown in the illustration will . Illustration MO-0127
Correct Answer A: shut off the oil feed to the separator
Answer B: be initiated by the water transducer or vibration switch
Answer C: cause the separator to automatically enter the sludge discharge cycle
Answer D: not be indicated in numerical order
 
306. (2.3.10.2.2-8) The system shown in the illustration utilizes a water transducer which is . Illustration MO-0127
Answer A: a mechanical/electrical device with a variable DC output
Correct Answer B: located in the oil outlet piping
Answer C: similar to those used in sonar systems
Answer D: essential in monitoring the amount of water entering the separator
 
307. (2.3.10.2.2-11) How may water be removed from the bowl of the separator as shown in the illustration? Illustration MO-0127
Correct Answer A: The water may be removed through the water drain valve or through the sludge ports during the sludge discharge cycle.
Answer B: The separator is used to remove solids from the processed liquid; therefore the accumulation of water does not present a problem.
Answer C: When the unit is secured and the bowl stops rotating, the water is drained off the bottom of the bowl through orifice ports.
Answer D: Water may only be removed from the bowl when the unit is secured and the bowl hood is removed.
 
308. (2.3.10.2.2-3) The greatest difference between the centrifuge bowl shown in the illustration and that of a tubular bowl, with straight, vertical, interior surfaces, is that the illustrated unit. Illustration MO-0012
Correct Answer A: is self-desludging
Answer B: rotates at 1000 rpm higher than the old tubular bowl type
Answer C: rotates at 1000 rpm slower than the old tubular bowl type
Answer D: does not require a discharge ring when operated as a separator
309. (2.3.10.4-3) The diesel engine shown in the illustration has the highest fuel pressure developed in the part labeled. Illustration MO-0003
Correct Answer A: E
Answer B: X
Answer C: Y
Answer D: Z
 
310. (2.3.10.4-2) Which of the listed types of gasket material should be used on high-pressure fuel oil lines on a diesel engine?
Answer A: Fiberglass
Answer B: Sheet asbestos
Answer C: Neoprene
Correct Answer D: Soft copper
 
311. (2.3.10.6-1) As shown in the illustration, the viscosimeter would be used to directly control the output of which of the following components? Illustration MO-0077
Answer A: Outflow from HFO day tank.
Correct Answer B: Final heaters.
Answer C: Injector pumps.
Answer D: HFO purifiers.
 
312. (2.3.10.7-1) Heavy fuel oil used in the system shown in the illustration will have the lowest viscosity. Illustration MO-0058
Answer A: in the settling tank
Answer B: at the transfer pump discharge
Correct Answer C: at the main engine fuel oil header
Answer D: in the three-way valve
 
313. (2.3.10.7-2) The purpose of the interlocked three-way valve shown in the illustration is to . Illustration MO-0058
Answer A: recirculate fuel through the heater during warm-up
Answer B: control the rate of fuel oil flow to the engines
Answer C: act as an emergency fuel shut off, regardless of the fuel being used
Correct Answer D: change fuel from heavy to light oil or vice versa while insuring that oil is returned to the proper day tank
314. (2.3.10.2.4-1) If the separating temperature is to remain constant, what is the relationship between the specific gravity of the oil and the required size of the regulating ring? Illustration MO-0113
Answer A: For a constant operating temperature, the greater the specific gravity of the oil the larger the regulating ring.
Answer B: The specific gravity of the oil and the size of the regulating ring are related only during the initial design stages of the centrifuge.
Answer C: With oils of greater specific viscosities it is proper to select smaller regulating rings regardless of the operating temperatures desired.
Correct Answer D: The larger sized regulating rings are designed to be used with oils of lower specific gravities.
315. (2.3.10.2.4-3) Using the graph shown in the illustration, the oil being separated has a specific gravity of 0.87 kg/dm3 at 72.5C. What will be the specific gravity if the temperature is lowered to 40C? Illustration MO-0113
Answer A: 0.872 kg/dm3
Answer B: 0.882 kg/dm3
Correct Answer C: 0.892 kg/dm3
Answer D: 0.902 kg/dm3
316. (2.3.10.2.4-4) From the graph shown in the illustration, if the separating temperature required is to be 167F, and the specific gravity of the oil is 0.98 kg/dm3 at 59F, what size regulating ring is required? Illustration MO-0113
Answer A: 86 mm
Answer B: 89 mm
Correct Answer C: 92 mm
Answer D: 95 mm
317. (2.3.10.2.4-2) From the graph shown in the illustration, determine the size of the regulating ring required for the proper operation of the fuel oil centrifuge if the fuel oil specific gravity is 0.9 kg/dm3 at 68F, and the separating temperature is 158F. Illustration MO-0113
Answer A: 86 mm
Answer B: 104 mm
Correct Answer C: 110 mm
Answer D: 117 mm
 
318. (2.3.13.1-1) Cooling the intake air supplied to a diesel engine will.
Answer A: reduce mean effective pressure
Answer B: decrease average compression ratio
Answer C: decrease air charge density
Correct Answer D: increase peak power output
 
319. (2.3.13.1-2) A large, low-speed, main propulsion diesel engine uses sea water to directly cool the
Answer A: cylinder heads
Answer B: exhaust valves
Correct Answer C: scavenging air
Answer D: injectors
320. (2.3.13.1-3) An increase in the air inlet manifold pressure of a diesel engine will result in a/an
Answer A: decrease in maximum cylinder pressure
Answer B: increase in ignition lag
Correct Answer C: decrease in fuel consumption per horsepower-hour
Answer D: decrease in exhaust manifold pressure
321. (2.3.13.1-4) In a naturally aspirated diesel engine, the volume of air intake is directly associated with engine.
Answer A: compression ratio
Correct Answer B: displacement
Answer C: fuel pressure
Answer D: cylinder clearance volume
322. (2.3.13.2-1) What is the function of the aftercoolers installed in the diesel engine air intake system?
Answer A: Decrease the air density
Answer B: Increase the exhaust temperature
Answer C: Decrease the lube oil temperature
Correct Answer D: Increase the air density
323. (2.3.13.2-2) The section of the turbocharger which would be connected to the aftercooler inlet is labeled. Illustration MO-0080
Correct Answer A: B
Answer B: C
Answer C: H
Answer D: K
 
324. (2.3.13.2-3) Item labeled 'R' as shown in section 6 of the illustration is identified as the . Illustration MO-0025
Correct Answer A: aftercooler
Answer B: non-return scavenge valve
Answer C: air filter
Answer D: exhaust manifold
 
325. (2.3.13.3-1) Which of the air intake systems listed will result in the lowest specific fuel consumption?
Answer A: Natural aspiration
Correct Answer B: Turbocharged
Answer C: Roots blower
Answer D: Piston blower
326. (2.3.13.3-2) Compared to a naturally aspirated diesel engine, a supercharged diesel engine has
Correct Answer A: a cylinder air charge of higher pressure
Answer B: reduced cylinder mean effective pressure
Answer C: less valve overlap
Answer D: reduced blow-by
327. (2.3.13.3-3) A naturally aspirated diesel engine at full throttle will have an intake manifold pressure.
Correct Answer A: slightly less than atmospheric pressure
Answer B: approximately equal to exhaust manifold pressure at all times
Answer C: that is widely fluctuating
Answer D: constantly decreasing as engine load increases
328. (2.3.14.1-1) The power consumed during the scavenging process of a diesel engine is known as the.
Answer A: compression loss
Answer B: valve loss
Answer C: back pressure loss
Correct Answer D: pumping loss
 
329. (2.3.14.1-2) The exhaust system for a turbocharged diesel engine functions to.
Answer A: power the aftercoolers
Correct Answer B: power the turbocharger
Answer C: reduce the cylinder scavenge effect
Answer D: cool the turbocharger
 
330. (2.3.14.1-3) Exhaust pipes for separate main propulsion diesel engines can be combined only when.
Answer A: space limitations prevent separately run pipes
Answer B: the engines are small auxiliary units
Correct Answer C: they are arranged to prevent gas backflow to each engine
Answer D: a waste heat boiler is installed
 
331. (2.3.14.1-4) One of the factors limiting the amount of load which can be put on a modern marine diesel engine is the.
Answer A: governor sensitivity
Correct Answer B: exhaust temperature
Answer C: fuel injection pressure
Answer D: speed of the camshaft
332. (2.3.14.1-5) In a diesel engine exhaust system, the cooling of the exhaust gases below their dew point, will result in.
Answer A: increased engine back pressure
Correct Answer B: sulfuric acid corrosion
Answer C: surface pitting of the turbocharger compressor blades
Answer D: moisture impingement on the turbocharger compressor blading
333. (2.3.14.1-6) The most common instrument used to measure diesel engine exhaust pressure is the
Answer A: pyrometer
Answer B: bourdon gauge
Answer C: pneumercator
Correct Answer D: manometer
334. (2.3.14.2-1) Which of the diesel engine exhaust mufflers listed is usually equipped with a spark arrestor?
Answer A: A wet-type exhaust muffler
Answer B: A constant pressure muffler
Correct Answer C: A dry-type exhaust muffler
Answer D: A constant velocity muffler
 
335. (2.3.14.3-1) A water jacket is placed around the exhaust manifolds of propulsion diesel engines to
Correct Answer A: reduce heat radiation to the engine room
Answer B: aid in preventing turbocharger overheating
Answer C: condense and drain moisture from exhaust gases
Answer D: dampen exhaust gas pulsations in the manifold
336. (2.3.15.1.1-1) In the engine shown in the illustration, the part labeled 'W' is cooled by . Illustration MO-0003
Answer A: lube oil
Answer B: convection
Answer C: air
Correct Answer D: sea water
337. (2.3.15.1.1-2) The diesel engine shown in the illustration, which of the lettered parts listed is cooled by sea water? Illustration MO-0003
Answer A: P
Answer B: Q
Correct Answer C: W
Answer D: Y
 
338. (2.3.15.1.2-1) The large, slow-speed, main propulsion diesel engine shown in the illustration, the part labeled 'B' contains. Illustration MO-0003
Answer A: exhaust gas
Answer B: oil
Answer C: diesel oil
Correct Answer D: water
339. (2.3.15.1.2-2) The outlet from an expansion tank of a closed fresh water cooling system should be piped to the.
Answer A: cylinder jacket inlet main
Answer B: heat exchanger inlet connection
Correct Answer C: jacket water pump suction line
Answer D: cylinder head water outlet header
 
340. (2.3.15.1.2-3) Which set of valves will be opened intentionally to remove heat from the main engine jacket cooling water system shown in the illustration? Illustration MO-0111
Correct Answer A: "A" and "C", "L" and "M"
Answer B: "B" and "D", "L" and "M"
Answer C: "G" and "H", "E" and "F"
Answer D: "J" and "K", "G" and "H"
 
341. (2.3.15.1.2-4) What is the function of the device labeled "3" shown in the illustration? Illustration MO-0111
Answer A: The device specifically serves to remove the latent heat of vaporization from the jacket water.
Correct Answer B: The cooler removes sensible heat from the jacket water.
Answer C: The heat exchanger serves to heat the jacket water during cold water operation.
Answer D: The jacket water cooler is used to raise the temperature of the sea water flowing through it.
342. (2.3.15.1.2-5) What is the function of the item "7" shown in the illustration? Illustration MO-0111
Correct Answer A: This jacket water pump circulates fresh water throughout the engine cooling and distiller heating systems.
Answer B: This circulating salt water pump will supply feedwater for the operation of the distiller.
Answer C: This jacket water pump supplies the distiller with sea water feed while also powering the eductors.
Answer D: This jacket water pump circulates salt water through the jacket water cooling system to provide engine cooling.
343. (2.3.15.1.3-1) Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce.
Answer A: cold corrosion of the nozzles
Answer B: fuel viscosity for better atomization
Correct Answer C: carbon accumulation on the nozzles
Answer D: fuel detonation in the cylinders
344. (2.3.15.1.4-1) The operation of the lube oil cooler, shown in the illustration as item No.4, will be characterized by which of the following statements? Illustration MO-0111
Answer A: The temperature of the lube oil entering the cooler will decrease whenever the distiller is on line.
Correct Answer B: The temperature of the sea water entering the cooler will be higher when operating with the distiller on line.
Answer C: The pressure of the lube oil to the cooler will increase whenever the distiller is on line.
Answer D: The pressure of the sea water to the lube oil cooler will increase with the distiller on line.
 
345. (2.3.15.1.5-1) What is the primary function of item '15' shown in the illustration? Illustration MO-0111
Answer A: It is the chemical cleaning pump used in conjunction with valve "12".
Answer B: It removes the vapor condensed in area "23".
Correct Answer C: It removes the distillate condensed in area "24".
Answer D: It is used to empty the evaporator section when there is tube leakage while the unit is secured.
346. (2.3.15.1.5-2) Which of the following statements represents the two major functions provided by the item labeled "20" shown in the illustration? Illustration MO-0111
Answer A: The pump supplies the motive force to the ejectors and removes the excess distillate.
Answer B: The pump is used to drain the shell when the unit is secured, in addition to powering the ejectors.
Answer C: The pump provides for venting of associated equipment while also powering the ejectors.
Correct Answer D: The pump supplies the motive fluid to the ejectors in addition to supplying the feedwater to the distiller.
347. (2.3.15.1.5-3) The items labeled "21" and "22", shown in the illustration are used to remove . Illustration MO-0111
Answer A: distillate and non-condensable gases
Answer B: non-condensable gases from two separate sections of the distiller
Answer C: brine and jacket water from the condenser
Correct Answer D: non-condensable gases and brine
348. (2.3.15.1.5-4) What occurs within the tubes of the device labeled "23" shown in the illustration? Illustration MO-0111
Correct Answer A: The feedwater flowing through the inside of the tubes is being heated by the jacket water on the outside of the tubes.
Answer B: The heat from the jacket water passing within the tubes is being transferred to the feedwater on the outside of the tubes.
Answer C: The heat of combustion from the engine is being transferred azeotropically, adding latent heat to the entering jacket water.
Answer D: The heat being transferred is subliminal; therefore expansion is taking place within the tubes.
349. (2.3.15.1.5-5) Which of the following statements describes what will occur to the volume of water vapor as it is exposed to the lower temperatures existing in the device labeled "24" shown in the illustration? Illustration MO-0111
Answer A: The volume is increased as condensation occurs at the tube surfaces.
Answer B: The volume will increase if the valve labeled "J" is opened excessively, resulting in an increase of the distiller absolute pressure.
Correct Answer C: The volume is greatly reduced, contributing to condensation within the condenser.
Answer D: The latent heat of condensation is removed causing the volume to increase.
 
350. (2.3.15.1.5-6) Device "27" shown in the illustration is used to. Illustration MO-0111
Answer A: purge the unit of non-condensable gases
Answer B: add de-scaling chemicals as needed
Correct Answer C: regulate maximum vacuum during normal operation
Answer D: relieve excess pressure
351. (2.3.15.1.5-7) Which of the valve arrangements listed would be correct for operating the distillation plant shown in the illustration? Illustration MO-0111
Answer A: Valves "C", "J", "K", "L", "M" open, valves "A", "B", "D", and "H" closed.
Answer B: Valves "D", "H", "J", "K", "L", "M" open, valves "I", "G", "F", and "E" closed.
Answer C: Valves "H", "J", "K", "L", "M" open, valve "D" closed.
Correct Answer D: Valves "J", "K", "L", "M" open, valves "D" and "H" closed.
 
352. (2.3.15.1.5-8) Excess brine accumulated in the distiller, shown in the illustration, is removed during normal operation by. Illustration MO-0111
Answer A: opening the drain valve located to the left of orifice "19"
Answer B: orifice "19" regulating the amount of feedwater entering the distiller, thereby preventing excess brine accumulation
Answer C: the hydrokineter labeled "21"
Correct Answer D: the continuous action of ejector "22"
 
353. (2.3.15.1.5-9) During operation which device listed removes air and non-condensable gases from the unit shown in the illustration? Illustration MO-0111
Correct Answer A: "21"
Answer B: "22"
Answer C: "25"
Answer D: "27"
354. (2.3.15.1.6-1) The graphic dotted line between items "27", "12", "9", and "20", shown in the illustration, is used to indicate the use of. Illustration MO-0111
Correct Answer A: electrical conduits and circuitry
Answer B: thermal venting devices
Answer C: ambient venting devices
Answer D: single wire controls
 
355. (2.3 .15.1.6-2) Excluding line losses, how many distinct pressure drops will occur as sea water flows through all the heat exchangers in the cooling system shown in the illustration? Illustration MO-0111
Answer A: 3
Answer B: 4
Correct Answer C: 5
Answer D: 6
356. (2.3.15.1.6-3) Which device is used to prevent overpressurization of the illustrated distiller? Illustration MO-0111
Answer A: "12"
Answer B: "13"
Answer C: "19"
Correct Answer D: "26"
 
357. (2.3.15.1.6-4) Where is the latent heat obtained to create vapor from the feedwater in the illustrated distiller? Illustration MO-0111
Answer A: During its contact period with heat exchanger "3".
Answer B: Only as it passes through device "20".
Correct Answer C: From having passed through "23".
Answer D: While it is in contact with device "24".
358. (2.3.15.1.6-5) Which of the following statements describes the approximate relation between the feedwater entering the unit shown in the illustration and brine being removed? Illustration MO-0111
Correct Answer A: Seventy-five percent of the feedwater entering the unit is removed as brine.
Answer B: The brine will be removed at a faster rate than feedwater entering to prevent the possibility of flooding.
Answer C: Twenty-five percent of the feedwater entering the device is removed as brine.
Answer D: The amount of feedwater entering the distiller is dependent upon the condition of device "7", while the amount of brine leaving is dependent upon the condition of device "21".
359. (2.3.15.1.6-6) Item "10" shown in the illustration is used to. Illustration MO-0111
Answer A: regulate flow from the drain pump
Answer B: prevent damage to device "9" by reducing turbulence
Correct Answer C: direct the flow from the distillate pump
Answer D: cancel the effects of improper regulation developed by device "11"
 
360. (2.3.15.2-1) Cooling water pumps driven by direct reversing diesel engines are usually
Answer A: curved impeller vane with concentric outlet
Answer B: straight impeller vane with tangential housing
Answer C: curved impeller vane with tangential outlet
Correct Answer D: straight impeller vane with concentric housing
361. (2.3.15.2-2) The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and.
Answer A: provide an air-cushion
Answer B: reduce water turbulence
Correct Answer C: allow for an increase in water volume as the engine warms up
Answer D: reduce water temperature
 
362. (2.3.15.2-3) The temperature at which an adjustable bellows type thermostatic valve operates is determined by.
Answer A: varying air loading pressure to the bellows
Correct Answer B: changing the spring compression opposing the bellows
Answer C: changing the position of the actuating bulb
Answer D: replacing the bellows with a heavier spring
363. (2.3.15.2-4) The thermostatic valve in the illustration is used for controlling the coolant temperature in a main propulsion diesel engine. Which of the following can be used to verify proper valve operation with the valve disassembled? Illustration MO-0079
Answer A: Check spring compression values against data given in manufacturer's handbook.
Answer B: Chemically analyze contents of power pellet.
Answer C: Remove and examine the contents of the power pellet.
Correct Answer D: Place the thermostatic element in a container of water at various operating temperatures and note the movement of the valve stem.
364. (2.3.15.2-5) Diesel engine jacket water is used in the fresh water distillation process as the
Correct Answer A: means of heating the feedwater
Answer B: primary means of producing a vacuum within the distiller
Answer C: coolant for the distillate
Answer D: coolant for the brine cooler
 
365. (2.3.15.2-6) A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water.
Correct Answer A: around the cooler
Answer B: around the engine
Answer C: overboard
Answer D: to the expansion tank
 
366. (2.3.15.2-7) What would be considered a normal temperature increase between the inlet and outlet jacket cooling water of a medium or high-speed diesel engine operating at normal load?
Answer A: 1 to 5F
Answer B: 5 to 10F
Correct Answer C: 10 to 20F
Answer D: 50 to 100F
 
367. (2.3.15.2-8) Which operating parameter may need to be decreased when running a large main propulsion diesel engine at low load conditions?
Correct Answer A: Cooling water flow through aftercoolers
Answer B: Control air supply pressure
Answer C: Lube oil temperature
Answer D: Fuel injection pressure
 
368. (2.3.15.2-9) Using a cooling water temperature of 225F (107.2C), instead of 180F (82.2C) in an auxiliary diesel engine, will.
Answer A: reduce the probability of scale formation in the jacket cooling passages
Answer B: increase fuel consumption per horsepower-hour
Correct Answer C: reduce the opportunity for the formation of sulfuric acid in the cylinder bore exhaust passages
Answer D: allow for smaller water passages within the engine
 
369. (2.3.15.2-10) As a general rule, what would be the recommended operating water jacket outlet temperature range for medium-speed marine diesels setup with closed treated fresh water cooling systems and fitted with vented expansion tanks?
Answer A: 105 to 120F
Answer B: 135 to 150F
Correct Answer C: 165 to 180F
Answer D: 195 to 215F
370. (2.3 .15.2-11) In a diesel engine closed fresh water cooling system, the cooling water pressure drop through the engine is 10 psig, and the pressure drop through the heat exchanger is 4 psig at maximum flow rates. The cooling water pump must produce a discharge head of at least
Answer A: 4 psig
Answer B: 6 psig
Correct Answer C: 15 psig
Answer D: 28.7 psig
371. (2.3.15.2-12) In a diesel engine jacket water cooler, with sea water cooling the fresh water, the
Correct Answer A: jacket water pressure should always be greater than the sea water pressure
Answer B: jacket water pressure must always be less than the sea water pressure
Answer C: jacket water temperature must always be less than 60F
Answer D: sea water temperature must never be warmer than 40F
372. (2.3.15.2-13) In a diesel engine closed fresh water cooling system employing a radiator, proper water temperature can be obtained by.
Answer A: passing cooling water through a space heater
Answer B: passing cooling water through the lube oil cooler
Answer C: piping exhaust gases across the radiator front
Correct Answer D: adjusting the radiator louvers
 
373. (2.3.15.2-14) If the jacket water temperature rises rapidly above normal in a diesel engine, you should FIRST.
Answer A: clean sea water strainer
Correct Answer B: reduce engine load
Answer C: call the chief engineer
Answer D: check thermostatic valve
 
374. (2.3 .16.1-6) When would the available energy of the exhaust gases of a two-stroke cycle diesel engine be insufficient to drive an exhaust gas turbocharger, resulting in the incorrect amount of air for combustion?
Answer A: During acceleration
Answer B: During operation at low load and speed
Answer C: During operation at rated speed, but low power output
Correct Answer D: All of the above
 
375. (2.3.16.1-2) Aftercooling of a turbocharged diesel engine will result in.
Answer A: higher torque but lower brake horsepower
Answer B: lower torque but higher brake horsepower
Correct Answer C: higher torque and higher brake horsepower
Answer D: lower torque and lower brake horsepower
 
376. (2.3.16.1-4) The process of scavenging a two-stroke cycle diesel engine serves to.
Answer A: improve fuel flow volume
Correct Answer B: cool the exhaust valves
Answer C: reduce the intake air charge density
Answer D: increase the temperature of exhaust gases
377. (2.3.16.1-10) Why will a turbocharged diesel engine produce black smoke if excessive additional load is applied too quickly?
Answer A: Exhaust energy would draw excess air.
Correct Answer B: The inertia of the turbocharger rotor causes a time lag which delays the turbocharger speed increase.
Answer C: Exhaust gas pumping losses are increased due to turbine windage.
Answer D: Exhaust gas back pressure falls slightly due to increased nozzle action.
378. (2.3.16.1-8) The average exhaust temperature of a two-stroke cycle diesel engine with a turbine- driven supercharger is lower than a similar four-stroke cycle diesel engine at equal loads because
Answer A: two-stroke cycle diesel engines have a higher M.E.P. than four-stroke cycle diesel engines
Answer B: four-stroke cycle diesel engine exhaust is cooled by scavenging air
Correct Answer C: two-stroke cycle diesel engines have a lower M.E.P. than four-stroke cycle diesel engines
Answer D: the opening of the two-stroke cycle diesel exhaust ports or valves occurs much later than in four-stroke cycle diesel engines
379. (2.3.16.6-1) The diesel engine shown in the illustration, is provided with an auxiliary blower to . Illustration MO-0003
Correct Answer A: provide scavenge air pressure at low load
Answer B: maintain a positive pressure on the crankcase
Answer C: increase scavenge air pressure at full load
Answer D: maintain a vacuum on the crankcase
 
380. (2.3.16.5-4) A loop or cross scavenged engine utilizes the motion of its pistons and a turbocharger to provide scavenging air. Which of the listed mechanical designs prevents the air under the pistons from being pumped back through the scavenge ports during the piston power stroke?
Correct Answer A: Length of the piston skirt
Answer B: Masked intake ports
Answer C: Lower liner seals
Answer D: Positive pressure from the blower
 
381. (2.3.16.5-1) The power consumed during the scavenging process of a diesel engine is known as the.
Answer A: compression loss
Answer B: valve loss
Answer C: back pressure loss
Correct Answer D: pumping loss
 
382. (2.3.16.5-3) During the valve overlap period, the exhaust pressure of a turbocharged, four-stroke cycle diesel engine must be less than the intake manifold pressure to ensure.
Correct Answer A: effective cylinder scavenging and cooling
Answer B: constant pressure from the turbochargers
Answer C: cooler operation of the exhaust system
Answer D: effective constant pressure for turbocharger operation
 
383. (2.3.16.5-2) Air scavenging of the cylinder shown in the illustration begins between figures . Illustration MO-0025
Answer A: 2 and 3
Correct Answer B: 3 and 4
Answer C: 4 and 5
Answer D: 5 and 6
 
384. (2.3.16.3-1) Large, two-stroke cycle, main propulsion, diesel engine cylinders can be successfully pressure charged during normal operation, by using the.
Answer A: exhaust gas temperature system
Answer B: exhaust load system
Correct Answer C: constant or pulse pressure system
Answer D: constant volume system
 
385. (2.3.16.3-3) Which of the turbocharging methods listed directs the exhaust gases to the turbine at fairly uniform velocity and pressure?
Correct Answer A: Constant pressure
Answer B: Pulse pressure
Answer C: Constant velocity
Answer D: Axial flow
 
386. (2.3.16.3-2) Which of the turbocharging systems listed operates with the least average back pressure in the exhaust manifold?
Answer A: Constant volume
Answer B: Constant pressure
Correct Answer C: Pulse pressure
Answer D: Radial flow
 
387. (2.3.16.4-1) In a Roots-type rotary blower, the volume of air delivered is directly proportional to
Correct Answer A: engine speed
Answer B: engine load
Answer C: brake horsepower
Answer D: brake specific fuel consumption
 
388. (2.3.16.4-2) Which of the designs listed will keep the lobes from making contact in a Roots-type blower?
Answer A: Drive chain
Correct Answer B: Blower timing gears
Answer C: Air trapped between blower lobes
Answer D: Oil filter between blower lobes
389. (2.3.16.4-3) In a two-stroke cycle diesel engine, a Roots-type blower is usually.
Correct Answer A: gear driven by the engine
Answer B: driven by an exhaust gas turbine
Answer C: actuated by the intake valves
Answer D: driven by separate motor
 
390. (2.3.16.2-6) Regarding the turbocharger shown in the illustration, the part labeled "B" would be attached to the. Illustration MO-0080
Answer A: nozzle ring
Answer B: silencer outlet
Answer C: exhaust manifold
Correct Answer D: aftercooler inlet
391. (2.3.16.2-2) Clearance volume scavenging in a turbocharged, four-stroke cycle diesel engine is accomplished.
Correct Answer A: during the valve overlap period
Answer B: with only the exhaust valve open
Answer C: at a pressure below atmospheric
Answer D: without cooling the cylinders or pistons
 
392. (2.3.16.2-4) In a turbocharger, inlet air velocity is increased in the.
Answer A: inlet nozzle ring
Answer B: stationary diffuser passages
Answer C: compressor outlet volute
Correct Answer D: rotating impeller vanes
393. (2.3.16.2-8) Which of the following statements is correct regarding a turbocharged four-stroke cycle diesel-generator?
Answer A: At zero load the intake manifold pressure is greater than the exhaust manifold pressure.
Answer B: At full load the intake manifold pressure and exhaust manifold pressure are equal.
Answer C: At full load the intake manifold pressure is less than the exhaust manifold pressure.
Correct Answer D: At full load the intake manifold pressure is greater than the exhaust manifold pressure.
 
394. (2.3.20.5-1) If governor Item No.19 in the illustration were to break on a diesel engine operating under full load, the engine RPM will. Illustration MO-0095
Answer A: increase until the overspeed trip actuated
Answer B: hunt until stabilized by droop rod
Correct Answer C: decrease to a slightly lower value
Answer D: remain the same until manually changed
 
395. (2.3.20.5-2) In the illustrated auxiliary diesel engine governor, decreasing the distance between piece No.6 and piece No.10 will affect the engine by. Illustration MO-0094
Answer A: decreasing the speed
Correct Answer B: increasing the speed
Answer C: increasing the speed droop setting
Answer D: decreasing the overspeed trip setting
 
396. (2.3.20.4-1) Which of the following statements is correct concerning the operating function of the governor shown in the illustration? Illustration MO-0096
Answer A: The dial type adjusting knob (B) is used for setting speed droop and damping out hunting.
Correct Answer B: Excess oil under high-pressure is released from the spring loaded accumulators to the sump.
Answer C: The speed droop lever spring prevents the engine from racing or hunting by arresting the movement of the power piston after a speed change.
Answer D: The compensating mechanism provides positive control to lower engine speed as load is increased.
397. (2.3.20.2-2) The direct acting mechanical governor used with some small diesel engines, controls fuel flow to the engine by.
Answer A: governor flyweight action on a pilot valve which controls fuel injection
Correct Answer B: governor flyweight motion acting on fuel controls through suitable linkage
Answer C: positioning a butterfly valve in the fuel delivery system
Answer D: positioning a servomotor piston attached to the fuel controls
 
398. (2.3.20.2-1) Direct reversible main propulsion diesel engines would normally be fitted with a/an
Answer A: constant speed governor
Correct Answer B: variable speed governor
Answer C: isochronous hunting governor
Answer D: nutating disk governor
 
399. (2.3.20.1-10) Diesel engines driving alternators operating in parallel must maintain a set frequency regardless of load changes. The governor characteristic used to accomplish this is known as.
Answer A: actuation
Answer B: sensitivity
Correct Answer C: compensation
Answer D: promptness
400. (2.3.20.1-4) Sensitivity for a diesel engine governor is described as the.
Answer A: governor's speed droop response to variations in engine load
Answer B: ability to maintain desired engine speed without speed fluctuation
Correct Answer C: percent of speed change necessary for corrective action by the fuel control
Answer D: ability to maintain constant speed regardless of engine load
401. (2.3.20.1-2) The device used to limit engine torque at various engine speeds is called a
Answer A: speed limiting governor
Answer B: variable speed governor
Answer C: constant speed governor
Correct Answer D: load limiting governor
402. (2.3 .20.1-6) The principal characteristic of an isochronous governor is it will.
Answer A: slow the machine down as the load is increased
Answer B: shut down the engine if it overspeeds
Answer C: display excessive speed droop
Correct Answer D: maintain a constant speed with variations of load
403. (2.3.20.1-8) Diesel engine control can be obtained by the bridge.
Answer A: with the approval of the chief engineer only
Correct Answer B: only after the engine room control station is switched to 'bridge control'
Answer C: whenever the secondary station is switched to 'bridge control'
Answer D: at any time
404. (2.3.20.3-6) In a simple hydraulic governor with speed droop, oil under pressure is maintained ready for use in the.
Answer A: power piston
Answer B: governor sump
Correct Answer C: spring-loaded piston accumulator
Answer D: pressure pilot valve assembly
405. (2.3.20.3-4) As the load is being decreased on the engine controlled by the governor shown in the illustration, the. Illustration MO-0092
Correct Answer A: right hand end of the floating lever will move up
Answer B: speeder rod will move down
Answer C: pilot valve plunger will move down
Answer D: oil pressure under the power piston will increase
 
406. (2.3.20.3-10) The function of the synchronizing motor on the generator governor illustrated is to . Illustration MO-0092
Answer A: drive the terminal shaft at a set speed
Answer B: turn the governor drive shaft during start-up
Correct Answer C: provide remote control for speed adjustment
Answer D: power the generator synchronizing lamps
407. (2.3 .20.3-2) The governor, shown in the illustration, will have its preset speed droop altered whenever. Illustration MO-0092
Answer A: the compensating lever fulcrum is changed
Correct Answer B: the speed droop lever fulcrum is changed
Answer C: the speeder spring tension is changed
Answer D: all of the above
 
408. (2.3.23.2-2) What is the best way of stopping an overspeeding diesel engine?
Answer A: Disconnect the battery cables from the starting motor.
Answer B: Drain the hydraulic fluid from the governor sump.
Answer C: Block the flow of cooling air to the radiator.
Correct Answer D: Secure the fuel supply and block the air intake
 
409. (2.3.23.2-1) An auxiliary diesel-generator continues to run after you try to shut down. Your next course of action should be to.
Correct Answer A: block the flow of air supply to the engine
Answer B: engage the jacking gear
Answer C: secure the lube oil pump
Answer D: decrease control air pressure
 
410. (2.3.23.3-1) Which of the listed conditions will result in the failure of an auxiliary diesel engine to shut down?
Answer A: Supplying high temperature inlet air.
Answer B: Maintaining a high exhaust back pressure.
Correct Answer C: Lube oil entering in the air intake manifold.
Answer D: Carbon buildup on the overspeed pawl.
 
411. (2.3.24.5-6) When a piston is removed from a diesel engine for maintenance, the piston should be examined for.
Answer A: cracks and burned spots
Answer B: scoring
Answer C: gummy deposits and sticking rings
Correct Answer D: all of the above
 
412. (2.3.24.5-2) The insertion of shims between the foot of a marine type connecting rod and a bearing box would result in.
Correct Answer A: increased compression ratio
Answer B: decreased compression ratio
Answer C: increased bearing clearance
Answer D: decreased bearing clearance
 
413. (2.3.24.5-8) Excessive side clearance between a piston ring and its groove will cause the ring to
Answer A: expand excessively under operating temperatures
Answer B: scuff the cylinder liner excessively
Answer C: hammer the piston land above the ring
Correct Answer D: hammer the piston land below the ring
 
414. (2.3.24.5-10) If the compression rings on a diesel engine piston become stuck in the ring groove, the cause may be due to.
Answer A: excessive ring action
Correct Answer B: excessive ring temperature
Answer C: improper ring rotation
Answer D: excessive ring face wear
415. (2.3 .24.5-4) After a long period of operation, a wear ridge, caused by piston ring action, will develop near the top of the cylinder liner. This ridge must be removed during maintenance in order to prevent.
Answer A: excessive ring wear during the seating period
Answer B: excessive lubrication of the top ring
Answer C: improper coating of lubrication on the cylinder wall
Correct Answer D: breaking of the rings, ring lands, or both during piston removal
416. (2.3.24.2-1) When installing the bearing cap on the device shown in the illustration, which of the precautions listed must be observed? Illustration MO-0121
Correct Answer A: Once the bearing cap is properly torqued, measure the end gap dimensions to ascertain even tightening of the cap.
Answer B: If the device is covered with abrasive material or contaminates, the unit may be reassembled, provided an abnormal method of reassembly is followed.
Answer C: Prior to installing the cap, position the thrust shoes in their proper locations.
Answer D: After applying anti-seize to the external threads, torque one side at a time to the appropriate values using a quality torque wrench.
417. (2.3 .24.2-2) What is the normal bearing clearance permitted at the horizontal axis of the shaft for the bearing shown in the illustration? Illustration MO-0121
Answer A: The clearance is determined by the thickness of the hydrodynamic wedge formed and is not usually measured while underway.
Answer B: The tolerances established are dependent on machining processes used and will vary amongst manufacturers.
Correct Answer C: The normal play on both sides of the shaft will be one tenth of a millimeter.
Answer D: The clearance on one side of the shaft at the axis will be one twentieth of a millimeter.
 
418. (2.3.24.2-3) After following the prescribed procedures to measure the thrust bearing clearance shown in the illustration, the distance "F" is determined to be 200 mm, and 'f1' is 2.3 mm. Which of the following statements describes the condition indicated by these dimensions? Illustration MO-0121
Answer A: These dimensions indicate the presence of flourishing marks on the thrust shoes; the marks becoming visible as the distance at 'f1' increases.
Correct Answer B: It is possible for the shaft to move axially 2.3 mm during astern operation and relates to an excess movement of 1.3 mm, 0.3 mm beyond the maximum worn play.
Answer C: The loading ratio, or shaft diameter divided by collar surface area is within 2.7:1.
Answer D: The total active thrust area is 202.3 mm, well within the standards set forth by the GSMA (German Society for Machining Accuracy).
 
419. (2.3.24.4-3) The spray holes in diesel engine fuel valves should be cleaned using carbon solvent and.
Answer A: diesel fuel
Correct Answer B: a special cleaning wire
Answer C: a copper wire brush
Answer D: a shaved wooden dowel
 
420. (2.3 .24.4-1) When running a large, dual fuel, main propulsion diesel engine on heavy fuel, which of the following precautions should be observed when switching from heavy fuel oil to diesel oil?
Correct Answer A: The temperature of the fuel from the preheater should be gradually reduced after switching over the three-way valve.
Answer B: The diesel oil must never be allowed to mix with the heavy fuel.
Answer C: The heating steam to the preheater should be increased as soon as the diesel fuel passes through the three-way valve.
Answer D: The heating steam must be secured before the diesel oil passes through the three-way valve.
421. (2.3.24.4-2) Air is normally bled from a diesel engine fuel system by.
Answer A: blowing down the air tanks
Correct Answer B: loosening the compression nuts at the injectors
Answer C: changing fuel filters
Answer D: pumping down the day tanks
422. (2.3.24.3-1) Because of the close tolerances used in diesel engine fuel oil pumps, a worn plunger requires.
Answer A: grinding the spare plunger to the barrel
Correct Answer B: replacing the plunger and the barrel
Answer C: highly polishing both the plunger and barrel
Answer D: replacing plunger only
 
423. (2.3.24.3-2) When a nozzle tester is being used to test a "closed" type fuel injection nozzle, a clogged nozzle orifice will be indicated by a .
Correct Answer A: distorted spray pattern
Answer B: chattering sound when the nozzle closes
Answer C: squealing sound midway in the pump stroke
Answer D: popping sound when the nozzle opens
 
424. (2.3.24.3-3) Which of the fuel nozzles listed requires the LEAST maintenance?
Correct Answer A: Pintle
Answer B: Single hole
Answer C: Multi-hole
Answer D: Open
 
425. (2.3.24.7-2) When tightening the lock ring "G" of the device shown in the illustration, two events are simultaneously accomplished. Which of the following statements represents these events? Illustration MO-0112
Answer A: The lock ring insures proper contact between the bowl top and the sliding bowl bottom, in addition to compressing the disc stack.
Answer B: The lock ring forces the disc stack onto the spindle, providing a positive means of rotation and locating the bowl top to seal the separation chamber.
Correct Answer C: When tightened, the lock ring allows for movement of the sliding piston and positions the sliding piston within the bowl bottom.
Answer D: The lock ring insures proper positioning of the disc stack and maintains a positive contact of the bowl top and bowl bottom.
426. (2.3.24.7-1) After removing the bowl hood of the device shown in the illustration, excessive quantities of sludge are visible. Which of the following statements represents the approach to rectify the situation? Illustration MO-0112
Answer A: Disassemble the entire unit, clean all components, replace all defective discs and use the proper lubricant where required.
Answer B: Steam clean the components in place, check for proper alignment, using the match marks provided, reassemble and restart the unit.
Answer C: Remove only the disc stack, separate all the discs, clean with steel wool and solvent, replace the disc stack ensuring it is located by use of the dowel pin shown.
Correct Answer D: Disassemble the entire unit, clean all components, replace any defective gaskets and use the proper lubricants where required.
427. (2.3.24.10-3) If a hydraulic governor has been refilled with oil, the engine should be operated until it reaches normal temperature, then the air should be purged, and the .
Answer A: rack position should be adjusted
Answer B: compensating needle valve should be opened fully
Correct Answer C: compensating needle valve should be adjusted to stabilize operation
Answer D: speed limiting device should be adjusted
 
428. (2.3.24.10-4) Adjustments to the compensating needle valve in a hydraulic governor should be made with the engine at.
Answer A: maximum power at a normal load
Answer B: maximum power and load under normal conditions
Answer C: half speed and normal temperature
Correct Answer D: normal operating temperature without a load
429. (2.3.24.10-1) A diesel-generator governor is hunting. After changing the oil, the governor is flushed and the compensation needle valve is adjusted, but the hunting persists. You should NOW
Answer A: check air intake manifold pressure
Answer B: calibrate the fuel pump rack settings
Answer C: set the speed droop adjustment to zero
Correct Answer D: carefully check for binding in the governor linkage
 
430. (2.3.24.10-2) The most common contaminate of governor hydraulic fluid is.
Answer A: moisture
Correct Answer B: dirt
Answer C: acid
Answer D: air
 
431. (2.3.24.11-1) When the timing gear backlash for a Roots-type blower has become excessive, the problem is properly repaired by.
Answer A: renewing the drive gear
Answer B: renewing the driven gear
Correct Answer C: renewing both driving and driven gears as a set
Answer D: shimming and pinning the gears with proper backlash
432. (2.3.24.9-2) When inspecting the valve mechanism shown in the illustration, normal maintenance would include. Illustration MO-0074
Answer A: mechanically adjusting the valve at point "D"
Answer B: mechanically adjusting the valve at point "E"
Answer C: changing the tappet clearance as measured between points "A" and "B"
Correct Answer D: measuring the cold valve clearance between components "C" and "D"
 
433. (2.3.24.9-1) Decreasing the exhaust valve clearance of a diesel engine will cause the exhaust valve to open.
Answer A: earlier and have less lift
Correct Answer B: earlier and remain open longer
Answer C: later and have greater lift
Answer D: later and have less duration
434. (2.3.24.9-3) Which of the following statements would apply when checking the valve clearance of the unit shown in the illustration? Illustration MO-0074
Answer A: Tappet clearance is measured between points "A" and "B".
Correct Answer B: Cold valve clearance is measured between components "C" and "D".
Answer C: The valve is mechanically adjusted at point "D".
Answer D: The valve is mechanically adjusted at point "E".
435. (2.3.24.8-3) In an auxiliary diesel engine, one reason for knurling the piston skirt is to
Correct Answer A: improve skirt lubrication
Answer B: allow for heat expansion
Answer C: transmit forces evenly
Answer D: improve the piston seal
 
436. (2.3.24.8-2) The service life of a worn aluminum piston for an auxiliary diesel, for which no spares are readily available, can be extended by.
Answer A: turning down the piston skirt to concentric values
Correct Answer B: knurling the piston skirt surface
Answer C: building up the piston skirt with a liquid epoxy material and then remachining
Answer D: increasing the dimensions of the ring land grooves
 
437. (2.3.24.8-1) Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must.
Answer A: place all control levers in the 'HOLD' position
Answer B: ensure that the hydraulic fluid reservoir is full
Answer C: block all hydraulic hoses using high-pressure covers
Correct Answer D: bleed off all hydraulic pressure from the system
 
438. (2.3.24.1-1) Sacrificial zinc anodes are used on the salt water side of diesel engine heat exchangers to.
Correct Answer A: reduce electrolytic action on heat exchanger metals
Answer B: provide a protective coating on heat exchanger surfaces
Answer C: keep heat transfer surfaces shiny and clean
Answer D: prevent rapid accumulation of marine growth
 
439. (2.3.24.1-4) If the coolant temperature is too low as it passes through internally cooled fuel injectors, the injectors can be damaged by.
Answer A: water condensation in the fuel
Correct Answer B: corrosion of the nozzle tip
Answer C: decrease in fuel oil viscosity
Answer D: inadequate lubrication of the needle valve
 
440. (2.3.24.1-3) Ethylene glycol, when used as a coolant in a closed cooling system for a diesel engine, is more advantageous than untreated raw water because it.
Correct Answer A: has a lower freezing point and higher boiling point
Answer B: provides a constant pH below 7
Answer C: provides better vapor-phase cooling
Answer D: has a higher freezing point and a lower boiling point
 
441. (2.3.25.2-1) Heavy fuel oils generally have an upper average ash content of 0.1% by weight. Which of the following conditions could be expected if the ash content increases above this amount?
Answer A: Glazing of the cylinder liners
Correct Answer B: Increased exhaust valve wear
Answer C: Excessive bearing wear
Answer D: Increased MEP
 
442. (2.3 .25.12-5) High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be caused by.
Correct Answer A: engine overload
Answer B: low combustion temperature
Answer C: plugged fuel nozzle holes
Answer D: excessive compression pressure
 
443. (2.3.25.12-3) A diesel engine may fail to start when being cranked, due to.
Answer A: high cetane number
Correct Answer B: insufficient compression
Answer C: low lube oil viscosity
Answer D: high lube oil pressure
444. (2.3.25.12-1) If an auxiliary diesel engine equipped with an electric starting system cranks very slowly after repeated attempts to start, the cause could be a/an.
Answer A: low lube oil viscosity
Answer B: low compression pressure
Answer C: ring gear with broken teeth
Correct Answer D: overheated motor windings
 
445. (2.3 .25.5-8) Which of the following statements describes what will occur if the annular spaces, indicated by the letter "K" of the device shown in the illustration, became restricted? Illustration MO-0112
Answer A: The bowl will fail to close, but the unit will be capable of shooting while in operation.
Answer B: Operating water will be supplied through port "S".
Answer C: The unit will not start due to pressure/time delay relays.
Correct Answer D: The bowl will fail to close when starting and the unit will not shoot when operating.
446. (2.3.25.5-2) As shown in the illustration, which of the following conditions would be responsible for a "low-pressure in oil outlet" alarm to be indicated? Illustration MO-0127
Correct Answer A: Throughput too low
Answer B: Separating temperature too low
Answer C: Controller setpoint changed
Answer D: Emergency stop button not reset
 
447. (2.3 .25.5-4) While operating the fuel oil centrifuge shown in the illustration, the bowl fails to open for sludge ejection. The probable cause is that. Illustration MO-0012
Answer A: one or more of the sludge ports is partially clogged
Answer B: the operating water pressure is too high
Answer C: the bowl disk set is clogged
Correct Answer D: the seal ring on the operating slide is defective
 
448. (2.3.25.5-6) While operating the fuel oil centrifuge shown in the illustration, the fuel oil is being continuously ejected with the sludge and the seal water. The probable cause is the. Illustration MO-0012
Correct Answer A: gravity disk inside diameter is too large
Answer B: gravity disk inside diameter is too small
Answer C: back pressure is too low
Answer D: incorrect number of disks have been placed in the disk stack
449. (2.3.25.13-2) If a single cylinder relief valve on a main propulsion diesel engine begins to lift, but it is not possible to secure the engine, which of the following actions should be taken?
Answer A: Increase the cooling water flow to the engine.
Correct Answer B: Secure or reduce fuel to that cylinder.
Answer C: Screw down on the pressure adjusting spring to decrease popping pressure.
Answer D: Readjust the injection timing.
 
450. (2.3 .25.13-6) Prior to starting, the purpose of turning over a main propulsion diesel engine with the cylinder test cocks open, is to.
Answer A: test the starting system
Correct Answer B: remove condensation and other liquids from the cylinders
Answer C: check the compression
Answer D: check for proper lube oil pressure
451. (2.3.25.13-7) The thrust bearing shown in the illustration has over eight years of ahead running time. Measurements show "i1" is 4 mm and "i2" is 1 mm. Which of the following conditions is indicated and what steps should be taken, if any? Illustration MO-0121
Correct Answer A: No appreciable wear has occurred, and the proper maintenance procedures should continue to be followed.
Answer B: A wear rate of 1.6 mm per year occurred. Although not excessive, this condition may require more frequent monitoring.
Answer C: The stops in which the thrust bearing block rides are worn, and it is necessary to return these to their original specifications.
Answer D: A wear rate of 1.6 mm per year is excessive and requires immediate assistance from the manufacturers field support.
452. (2.3.25.13-4) Crank web deflection readings will give a positive indication of.
Correct Answer A: worn main bearing journals
Answer B: crank pin misalignment
Answer C: slack thrust bearings
Answer D: bearing shells shim dimensions
453. (2.3.25.4-4) When a fuel injection nozzle overheats, which of the problems listed can be expected?
Correct Answer A: The fuel metering will vary.
Answer B: The fuel will explode.
Answer C: The cylinder head will crack.
Answer D: The engine will stop.
 
454. (2.3 .25.4-12) In the common rail system, excessive pressure in the header may be caused by
Correct Answer A: improper adjustment of the bypass valve
Answer B: a dribble in the fuel injection nozzle
Answer C: insufficient leakoff through injection nozzle packing
Answer D: a malfunctioning injection nozzle
455. (2.3.25.4-14) Surface irregularities, such as erosion and pitting on injection pump plungers, will
Answer A: increase ignition delay
Correct Answer B: affect fuel oil metering
Answer C: affect engine performance at low-speed only
Answer D: disappear due to fuel oil abrasion
456. (2.3 .25.4-8) High cylinder firing pressure, accompanied by low exhaust temperature, can result from.
Answer A: improper fuel rack positioning
Answer B: lengthy exhaust valve duration
Answer C: extended operation at light load
Correct Answer D: excessively early injection timing
 
457. (2.3 .25.17-1) A diesel engine operates erratically, overspeeds, and fails to restart when cranked at normal speed. Which of the following problems is the most likely cause for the engine failing to restart?
Answer A: Improper governor operation due to excess oil pressure
Answer B: Damage to the governor due to excessive speed
Correct Answer C: Failure to reset the overspeed trip
Answer D: Failure to reposition the fuel rack
458. (2.3.25.17-2) A propulsion engine, using the speed control circuit shown in the illustration, fails to function at speeds lower than the low end of the critical speed range. Which of the following statements describes what should be done to correct this malfunction? Illustration MO-0114
Correct Answer A: Device 17A needs to be replaced, repaired, or reset to the setpoint coinciding with the RPM value for the low end of the critical speed range.
Answer B: The critical speed range will be varied as the setpoints of 17A or 17B are reset, therefore, another segment of the speed control circuit must be repaired.
Answer C: To increase the critical speed range of the engine, reduce the setpoint of 17A and 17B respectively, to 0.80 bar and 1.0 bar.
Answer D: Both 17A and 17B need to be reset to decrease the critical speed range, although this procedure will increase the operating range of the engine.
 
459. (2.3 .25.15-3) What would be the first indication that a tube leak has occurred in area '23'? Illustration MO-0111
Correct Answer A: The level in area '1' would decrease.
Answer B: The level in area '1' would increase.
Answer C: The level in area '3' would decrease.
Answer D: The level in area '3' would increase.
460. (2.3.25.15-1) If the wearing rings of device '7' shown in the illustration become worn, how will the evaporation rate in '23' be affected? Illustration MO-0111
Correct Answer A: The rate of evaporation will decrease.
Answer B: The rate of evaporation is dependent on the level of vacuum maintained within the unit, and not the flow of water to the unit.
Answer C: Device '7' does not use wearing rings, as these are normally positive displacement pumps.
Answer D: The rate of evaporation will not be affected as the standby pump; labeled '8' will be used instead.
 
461. (2.3.25.15-4) Which of the conditions listed would indicate a large condenser tube leak within the distiller shown in the illustration? Illustration MO-0111
Correct Answer A: The activation of the salinity monitoring equipment's annunciator circuit.
Answer B: A decrease in the level of the main engine expansion tank as indicated by a low level alarm.
Answer C: An increase in distiller output resulting from the combination of jacket water and the distillate produced.
Answer D: A slow continuous rise in the lube oil cooler outlet temperature indicated at device "4".
462. (2.3.25.15-2) If valve "D" is opened during the normal operation of the distiller shown in the illustration, which of the events listed will occur? Illustration MO-0111
Answer A: The jacket water cooler will be overloaded, eventually causing a critical engine alarm.
Answer B: The amount of vapor formed in the evaporator will increase.
Answer C: The output of pump "7" will increase with a corresponding increase in pressure.
Correct Answer D: The amount of vapor being formed in the evaporator will decrease.
463. (2.3.25.9-5) A diesel engine may be hard to start if the.
Correct Answer A: air intake is restricted
Answer B: engine is cranked too fast
Answer C: vibration dampener is faulty
Answer D: exhaust back pressure is low
464. (2.3.25.9-3) Clogged or partially obstructed exhaust ports on a diesel engine can cause
Answer A: overspeeding of the engine
Answer B: failure of the engine to shut down
Answer C: no effect of engine performance
Correct Answer D: high exhaust temperatures
465. (2.3.25.9-1) A four-stroke cycle main propulsion diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperature. The reason for the failure could be
Answer A: glazed liners or pistons
Answer B: high lube oil pressure
Answer C: excessive compression ratio
Correct Answer D: excessive air leakage by rings and valves
 
466. (2.3.25.10-10) A diesel engine cylinder head can crack as a result of
Answer A: a leaking oil control ring
Answer B: heat transfer from exhaust valves
Answer C: overheated intake valves
Correct Answer D: restricted cooling passages
 
467. (2.3 .25.10-2) Combustion gas venting through the expansion tank can be caused by a
Answer A: leaking oil cooler
Correct Answer B: cracked cylinder head
Answer C: worn piston ring
Answer D: leaking exhaust valve
468. (2.3.25.10-14) Antifreeze solutions containing ethylene glycol should not be mixed with corrosion protection oils, as the resultant mixture.
Answer A: is dangerously flammable
Answer B: has a higher chloride content
Correct Answer C: may cause frothing
Answer D: promotes scale buildup
 
469. (2.3.25.10-6) Some diesel engines are fitted with a thermometer in the cooling water outlet from each cylinder. If the cooling water temperature from all cylinders begins to rise above normal, you should suspect.
Answer A: insufficient fuel delivery to all cylinders
Answer B: increased blow-by in all cylinders
Answer C: incomplete combustion in all cylinders
Correct Answer D: overloading in all cylinders
470. (2.3 .25.8-2) What could cause the bypass valve in a full-flow lubrication system to open?
Correct Answer A: Clogged filter element
Answer B: Bypass valve setting is too high
Answer C: Check valve stuck open
Answer D: Fuel dilution of the lubricant
471. (2.3 .25.8-6) Which of the following effects will excessively cold lube oil have on the operation of a diesel engine?
Correct Answer A: The engine will crank slowly and may fail to start.
Answer B: The engine will overspeed when started.
Answer C: The fuel oil supply will become diluted resulting in rough running.
Answer D: The cooling system will overheat causing the engine to stall.
472. (2.3.25.8-4) Lube oil in the fresh water cooling system of a diesel engine may result from a
Answer A: camshaft seizure
Answer B: lube oil pump failure
Correct Answer C: lube oil cooler failure
Answer D: lube oil sump overflow
 
473. (2.3.25.6-2) On a diesel engine with direct-cylinder admission air starting, a leaking air starting valve would be indicated by.
Correct Answer A: an overheated starting air supply pipe
Answer B: excessive smoke from the engine exhaust
Answer C: carbon deposit on the exhaust valves
Answer D: early fuel ignition
 
474. (2.3 .25.6-1) For a diesel engine, approximately how long can an electric starter motor be operated continuously before damage may begin to occur due to overheating?
Correct Answer A: Not more than 30 seconds
Answer B: Not more than 60 seconds
Answer C: Not more than 90 seconds
Answer D: Overheating the motor cannot occur.
475. (2.3.25.6-4) When starting air is admitted, a diesel engine turns over very slowly without firing. The cause may be.
Answer A: an obstruction in an engine cylinder
Answer B: water accumulation in some engine cylinders
Correct Answer C: low starting air pressure
Answer D: low scavenge air pressure
476. (2.3 .25.6-3) Which of the following conditions is most likely to occur if the electric starter motor pinion gear fails to disengage from the flywheel of a diesel engine after the engine has started?
Answer A: Engine will stop
Correct Answer B: Starting motor will dangerously overspeed
Answer C: Flywheel will be damaged
Answer D: Combustion gases will enter the air starting system
 
477. (2.3 .25.18-2) The power output of a turbocharged diesel engine will drop if the cooling water flow through the aftercooler is interrupted because the.
Answer A: turbocharger stalls
Answer B: exhaust pressure increases
Correct Answer C: air charge density decreases
Answer D: scavenge effect increases
 
478. (2.3 .25.18-4) Corrosion and grooving on the blading of an exhaust driven turbocharger is caused by certain components of residual fuel oils. These components are vanadium, sodium, and
Answer A: copper
Answer B: carbon
Answer C: hydrogen
Correct Answer D: sulfur
 
479. (2.3.25.18-6) Excessive mechanical and pulsating vibrations developed in a main propulsion diesel engine may be more likely to cause damage to an attached .
Answer A: scavenged air pump because it is designed for steady state operation rather than pulsating gas load
Answer B: reciprocating scavenge pump because of its direct linkage to the crankshaft
Answer C: centrifugal cooling water pump because of the close tolerances required between the impeller rim and the volute
Correct Answer D: gas driven turbocharger because it has a wide speed range, high operating temperatures and close tolerances.
480. (2.3.25.16-4) If the speeder spring of a main propulsion diesel engine governor breaks while operating at full load, the engine RPM will.
Answer A: increase until the overspeed trip is actuated
Answer B: hunt until stabilized by the droop rod
Correct Answer C: decrease to a slightly lower value
Answer D: remain the same until manually changed
 
481. (2.3.25.16-3) The hunting of a diesel engine may be caused by.
Answer A: excessive speed droop
Answer B: insufficient speed droop
Answer C: excessive sensitivity
Correct Answer D: low governor power
 
482. (2.3.25.16-1) If the operating speed of a diesel engine increases without an apparent change in the engine control settings, you may suspect a.
Answer A: clogged intake air intercooler
Answer B: control air leak
Answer C: leaking air starting valve
Correct Answer D: malfunctioning governor
483. (2.3.25.16-2) Governor hunting is caused by.
Answer A: governor under-control
Answer B: excessive speed droop
Answer C: insufficient speed droop
Correct Answer D: governor over-control
 
484. (2.3.25.14-2) Excessive vibration from an auxiliary boiler could be caused by.
Answer A: loose hold-down bolts
Answer B: insufficient air to the burner
Answer C: combustion pulses
Correct Answer D: all of the above
485. (2.3.25.14-6) Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?
Answer A: Increased suction head pressure
Answer B: Decreased feedwater temperature
Answer C: Pump recirculating line being open too much
Correct Answer D: Excessive feedwater temperature
 
486. (2.3.25.1-2) If sludge accumulates on the underside of a diesel engine piston, it will
Answer A: cause blow-by
Answer B: chemically attack the piston skirt
Answer C: form an emulsion of lube oil and water
Correct Answer D: raise the piston temperature
 
487. (2.3.25.1-6) Before being shut down, a diesel engine should idle a few minutes in order to
Answer A: prevent governor surging at shutdown
Answer B: make sure the fuel nozzles are flushed clean
Answer C: prevent pressure buildup in the fuel lines
Correct Answer D: prevent damage from localized overheating
488. (2.3.25.1-11) The diesel engine shown in the illustration can be fitted with a pyrometer at each exhaust elbow. If one of the cylinder pyrometers is reading significantly higher than the others, which of the following should be your FIRST action? Illustration MO-0005
Correct Answer A: Check the pump rack setting.
Answer B: Examine the water outlet header for evidence of blockage.
Answer C: Replace the fuel injector nozzle.
Answer D: Examine the exhaust valves for evidence of burning.
 
489. (2.3.25.1-4) The instrument shown in the illustration would be used on a diesel engine to . Illustration MO-0031
Correct Answer A: measure cylinder compression or firing pressures
Answer B: balance exhaust gas temperature readings
Answer C: measure exhaust gas pressure
Answer D: measure concentration of chromate in jacket water
 
490. (2.3.25.1-15) White smoke issuing from the exhaust of an auxiliary diesel engine could mean
Answer A: the engine is overloaded
Correct Answer B: the engine is cold
Answer C: there is too much lube oil in the cylinders
Answer D: the turbocharger is fouled
491. (2.3.25.1-7) If the relief valve on a diesel engine cylinder lifts, the cause could be due to
Correct Answer A: liquid in the cylinder
Answer B: low compression in the cylinder
Answer C: high exhaust temperature
Answer D: poor fuel penetration
 
492. (2.3 .25.11-1) Oil accumulating in the exhaust piping or manifold of a diesel engine can be caused by.
Answer A: collapsed hydraulic valve lifters
Correct Answer B: worn valve guides
Answer C: excessive crankcase vacuum
Answer D: excessive lube oil pressure
493. (2.3.25.11-3) If there is a 'clicking' sound in the valve compartment of a diesel engine, the cause may be.
Correct Answer A: excessive valve lash
Answer B: a worn wrist pin
Answer C: worn connecting rod bearings
Answer D: all of the above
 
494. (2.3.25.11-5) Excessive wear at part No.11, shown in the illustration would result in Illustration MO-0027
Answer A: improper timing
Correct Answer B: increased oil consumption
Answer C: lost compression
Answer D: low oil pressure
 
495. (2.3.25.7-3) The gear drive, shown in the illustration, can have the backlash determined best by using a. Illustration MO-0091
Answer A: lead wire
Correct Answer B: feeler gauge
Answer C: lash indicator
Answer D: red dye indicator
 
496. (2.3.25.7-1) When an additional load is applied to a diesel engine which is using an inadequately inflated air bladder clutch unit, you can expect.
Answer A: pneumatic seizure
Correct Answer B: overheating because of slipping shoes
Answer C: chipped reduction gear teeth
Answer D: excessive wear on the thrust bearings
497. (2.3.25.7-2) Misalignment of the drive shaft and propeller shaft flanges can be detected by using a dial indicator or.
Answer A: inside micrometer
Correct Answer B: feeler gage
Answer C: adjustable trammel
Answer D: sighting device
 
498. (2.3.25.3-3) One cause of diesel engine fuel ignition delay is.
Answer A: mechanical flexibility in the pump mechanism
Answer B: low fuel booster pump pressure
Answer C: high fuel rack setting
Correct Answer D: ignition quality of the fuel oil
 
499. (2.3.25.3-1) When running a large, dual fuel, main propulsion diesel engine on heavy fuel, which of the following precautions should be observed when switching from heavy fuel oil to diesel oil?
Answer A: The diesel oil must never be allowed to mix with the heavy fuel.
Correct Answer B: The temperature of the fuel from the preheater should be gradually reduced after switching over the three-way valve.
Answer C: The heating steam to the preheater should be increased as soon as the diesel fuel passes through the three-way valve.
Answer D: The heating steam must be secured before the diesel oil passes through the three-way valve.
 
500. (2.3.25.3-2) When restarting a heavy fuel diesel engine that has been stopped for some time, the engineer should.
Answer A: increase the starting air pressure
Answer B: use a higher than normal cranking speed
Answer C: increase the fuel injection pressure
Correct Answer D: use a fuel having a lower ignition temperature
501. (2.3 .26.1-2) Before any work is to be carried out on a burner in an automatically fired auxiliary boiler, you should always.
Answer A: block all control system relays closed
Answer B: allow the boiler to cool completely
Correct Answer C: close all manually operated fuel valves
Answer D: lock all safety interlock switches closed
 
502. (2.3.26.6-1) Which of the following precautions should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger?
Answer A: Reduce engine speed to idle before removing the filter.
Answer B: Soak the dirty filter in kerosene only.
Answer C: Blow out the air inlet with compressed air.
Correct Answer D: With the engine stopped, cover the air inlet after removing the filter.
503. (2.3 .26.5-2) The principal hazard to personnel when using a diesel engine fuel nozzle tester is
Answer A: electrical shock
Answer B: toxic fumes
Answer C: explosion
Correct Answer D: blood poisoning
 
504. (2.3.26.5-3) An immediate repair is required if a leak occurs in the high-pressure fuel piping between the injection pump and fuel nozzle because of the.
Answer A: high cost of fuel
Correct Answer B: serious fire hazard
Answer C: pollution hazard
Answer D: poor combustion which will occur in that cylinder
 
505. (2.3.26.5-1) When a nozzle tester is used to check the spray pattern of a diesel fuel injection nozzle, which of the following statements is true?
Answer A: The valve should normally begin to open at 1/2 the popping pressure
Answer B: The needle valve spring should always be removed first before testing
Answer C: The needle valve should remain open after the nozzle pops open
Correct Answer D: A serious hazard of blood poisoning exists if the fuel spray penetrates the skin of the operator
 
506. (2.3 .26.4-1) When cleaning a duplex strainer, it is important for.
Correct Answer A: the pressure to be bled prior to opening the compartment cover
Answer B: the lube oil to be allowed to cool before removing the basket
Answer C: the cleaning fluid viscosity to be more viscous than the lube oil
Answer D: a new cover gasket to be installed when reassembling the unit
 
507. (2.3 .26.2-1) The starter control valve in the hydraulic system shown in the illustration is malfunctioning. Before removing the valve, you must first. Illustration MO-0049
Answer A: drain the reservoir
Answer B: remove all plugs from the system
Correct Answer C: bleed off all accumulator pressure in "E"
Answer D: ensure that the accumulator piston is in the charged position
508. (2.3.26.2-2) Which of the listed items should be secured before performing any maintenance on a solenoid operated air start valve?
Correct Answer A: Electric power and starting air
Answer B: Lube oil standby pump and control air
Answer C: Hydraulic switch and engage jacking gear
Answer D: Motor drain and pneumatic control system power
509. (2.3 .26.3-1) If a diesel engine has been stopped because of piston seizure due to severe overheating, the crankcase.
Correct Answer A: inspection covers should not be opened until the engine has cooled
Answer B: ventilation system should be continued in operation for one hour for cooling
Answer C: scavenge pump should be immediately secured to prevent loss of lube oil
Answer D: explosion covers should be opened slightly to provide extra ventilation
 
1. (3.4.1.2.2-2) During main engine performance testing it is noticed that the firing pressure of one cylinder is higher than the average, but cylinder compression pressure is normal. Which of the following would most likely be the cause?
Correct Answer A: Early fuel injection
Answer B: Worn piston rings
Answer C: High engine load
Answer D: Late fuel injection
2. (3.4.1.2.2-3) During main engine performance testing it is noticed that one cylinder has firing and compression pressures lower than average. Which of the following would most likely be the cause?
Answer A: Early fuel injection
Answer B: Low engine load
Correct Answer C: Worn piston rings
Answer D: Late fuel injection
 
3. (3.4.1.1.2-15) The lower water seal on a diesel engine wet cylinder liner must allow for liner axial movement. This seal is most commonly a.
Answer A: flexible metallic seal ring
Correct Answer B: neoprene O-ring
Answer C: precision ground flange joint
Answer D: soft copper gasket
4. (3.4.1.1.2-2) Which construction detail is apparent in the connecting rod and piston assembly shown in the illustration? Illustration MO-0011
Correct Answer A: The piston is designed with a heat dam.
Answer B: It is a fork assembly.
Answer C: The piston is water cooled.
Answer D: The wrist pin is free floating.
 
5. (3.4.1.1.2-14) Why are some diesel engine cylinder liners plated on the wearing surface with porous chromium?
Answer A: The chromium will not wear out the piston rings.
Answer B: The chromium strengthens the liners in the way of the scavenging air ports.
Answer C: Chromium eliminates the need for oil scraper rings.
Correct Answer D: Pores in the plating aid in maintaining the lube oil film.
6. (3.4.1.1.2-13) The diesel engine shown in the illustration utilizes the type of cylinder construction identified as. Illustration MO-0007
Answer A: a dry liner
Correct Answer B: a wet liner
Answer C: integral with a removable sleeve
Answer D: integral with a non-removable sleeve
 
7. (3.4.1.1.2-4) Which of the following statements is correct concerning the connecting rod and piston assembly shown in the illustration? Illustration MO-0011
Answer A: The piston is free to rotate on the carrier thrust washer.
Answer B: The piston pin is bolted to the connecting rod.
Answer C: The piston has a heat dam.
Correct Answer D: All of the above.
8. (3.4.1.1.2-6) Piston cooling fins are located.
Answer A: on top of the piston crown
Correct Answer B: underneath the piston crown
Answer C: at the base of the piston skirt
Answer D: inside the cylinder liner cooling water jacket
 
9. (3.4.1.3.3-1) Which of the conditions listed could cause the cylinder relief valves on a large, low- speed, propulsion diesel engine to lift?
Answer A: Plugged injector nozzles
Correct Answer B: Excessive fuel injection
Answer C: Incorrect crankshaft clearances
Answer D: Very late injection timing
 
10. (3.4.1.3.3-7) Which of the following procedures should be carried out to permit the continued operation of a crosshead engine with a leaky aftercooler?
Answer A: Bypass the aftercooler to operate at sea speed.
Answer B: Switch to diesel fuel and run at reduced speed.
Answer C: Nothing needs to be done due to the low heating value of heavy fuel.
Correct Answer D: Blank off the cooling water lines and run at reduced speed.
11. (3.4.1.3.3-6) A main propulsion diesel engine crankshaft bearing lacking sufficient 'crush', will
Correct Answer A: tend to rotate with the journal
Answer B: pound under load
Answer C: have a thicker layer of babbitt
Answer D: be lubricated more easily than with sufficient crush
 
12. (3.4.1.3.3-2) The ring lands on a large, low-speed, main propulsion diesel engine piston may crack due to.
Answer A: high main lubricating oil system temperature
Correct Answer B: insufficient ring groove clearance
Answer C: insufficient cylinder liner wear
Answer D: contaminated lubricating oil
13. (3.4.1.3.3-5) One method of determining crankshaft misalignment is by.
Answer A: laying a straight edge across the crank webs at the crankpin and measuring the distance to the crankpin in two places
Correct Answer B: taking micrometer readings between the crank cheeks opposite the crankpin every 90 of crank angle rotation
Answer C: measuring the crank drop on either side of each crank throw while the crankshaft is slowly rotated through one revolution
Answer D: rotating the crankshaft through one revolution, pausing each 90 of rotation to measure bearing clearances, top and bottom
 
14. (3.4.1.3.3-3) When inspecting pistons, liners, and rings of a large two-stroke cycle diesel engine through the cylinder ports, a wet piston crown would indicate a.
Answer A: faulty oil ring
Correct Answer B: leaky fuel injector
Answer C: faulty piston lubricator
Answer D: broken compression ring
15. (3.4.1.3.3-4) The most practical way of detecting an overload in one cylinder of an operating large, low-speed, main propulsion diesel engine is to.
Answer A: listen for combustion knock in that cylinder
Answer B: isolate each cylinder and inspect the injector
Answer C: check the cylinder exhausts for black smoke
Correct Answer D: check the cylinder exhaust temperature frequently
 
16. (3.4.1.3.1-11) When one cylinder has a lower compression pressure and higher exhaust gas temperature than any of the other engine cylinders, which of the conditions listed will be indicated?
Answer A: Advanced ignition
Answer B: Clogged air intake
Correct Answer C: Leaky exhaust valve
Answer D: High exhaust pressure
17. (3.4.1.3.1-3) If a valve seat insert, similar to that shown in the illustration is cracked, this may be indicated by. Illustration MO-0043
Correct Answer A: white vapor in the exhaust gas
Answer B: high exhaust pyrometer readings on that particular cylinder
Answer C: continuous spring surge
Answer D: a jammed indicator cock
 
18. (3.4.1.3.1-6) Bouncing of the valve gear in a diesel engine can be caused by.
Answer A: prolonged high-speed operation
Correct Answer B: spring surge
Answer C: worn valve seats
Answer D: excessively tightened spring retainers
19. (3.4.1.3.1-2) Excessive wear at part #11, as shown in the illustration, would result in. Illustration MO-0027
Answer A: improper timing
Correct Answer B: increased oil consumption
Answer C: lost compression
Answer D: low oil pressure
 
20. (3.4.1.3.1-9) Worn diesel engine intake valve guides can result in.
Answer A: increased engine breathing efficiency
Answer B: excessive valve lash
Correct Answer C: excessive lube oil consumption
Answer D: lower than normal fuel consumption
21. (3.4.1.3.1-1) Low compression pressure in a diesel engine can be caused by.
Correct Answer A: improperly seating intake valves
Answer B: leaking cylinder liner seal rings
Answer C: late fuel injection timing
Answer D: carbon deposits on the piston
22. (3.4.1.3.1-10) Oil accumulating in the exhaust piping or manifold of a diesel engine can be caused by.
Answer A: collapsed hydraulic valve lifters
Correct Answer B: worn valve guides
Answer C: excessive crankcase vacuum
Answer D: excessive lube oil pressure
 
23. (3.4.1.1.1-9) Telescopic pipes which are attached to water cooled pistons of large, slow-speed, main propulsion diesel engines are designed to.
Answer A: overcome excessive crankcase pressure
Answer B: prevent excessive lube oil temperature
Correct Answer C: allow piston cooling water to efficiently enter the piston despite its reciprocating piston motion without contaminating the engine lube oil
Answer D: prevent contamination of the cylinder cooling water with engine lube oil
24. (3.4.1.1.1-3) In the illustrated engine, the main camshaft controls the timing of which of the following components? Illustration MO-0003
Answer A: exhaust valves
Correct Answer B: fuel pumps
Answer C: Intake valves
Answer D: all of the above
 
25. (3.4.1.1.1 -1) Which of the listed design features is most common with a two-stroke cycle, low-speed main propulsion diesel engine?
Correct Answer A: Piston rod and crosshead construction
Answer B: 90 degree 'V' configuration
Answer C: Double acting trunk type pistons
Answer D: Single reduction gearing
26. (3.4.1.1.1-6) The piston rod scraper box incorporated in a two-stroke cycle, crosshead diesel engine serves to.
Answer A: eliminate the necessity for an oil scraper ring
Answer B: prevent side thrust and cylinder scoring
Correct Answer C: prevent sludge and dirty oil from entering the crankcase
Answer D: scrape oil and carbon deposits off the cylinder walls
 
27. (3.4.1.1.1-8) In what figure of the illustration does the crosshead experience the greatest side thrust? Illustration MO-0025
Answer A: Figure 1
Correct Answer B: Figure 2
Answer C: Figure 5
Answer D: Figure 6
 
28. (3.4.1.1.1-5) There are two glands provided where the piston rod exits the cylinder shown in the illustration. The purpose of the top gland is to. Illustration MO-0083
Answer A: prevent crankcase oil leaking out
Correct Answer B: seal against scavenge air leakage
Answer C: maintain crankcase vacuum
Answer D: maintain crankcase pressure
29. (3.4.1.1.1-4) The lower end of the piston rod, shown in the illustration, is fitted into the. Illustration MO-0003
Answer A: crankpin
Correct Answer B: crosshead
Answer C: piston pin
Answer D: crosshead guide
 
30. (3.4.1.1.1-10) If the speed of the propeller is 135 RPM, the speed of the engine camshaft shown in the illustration will be. Illustration MO-0003
Correct Answer A: 135 RPM
Answer B: 270 RPM
Answer C: variable depending on the camshaft gear train gear ratios
Answer D: variable depending on the ratio between engine rpm and propeller shaft rpm
31. (3.4.1.2.1-2) Which of the following statements would apply when checking the valve clearance of the unit shown in the illustration? Illustration MO-0074
Answer A: The valve is mechanically adjusted at point "D".
Answer B: The valve is mechanically adjusted at point "E".
Answer C: Tappet clearance is measured between points "A" and "B".
Correct Answer D: Cold valve clearance is measured between components "C" and "D".
 
32. (3.4.1.2.1-4) When inspecting the valve mechanism shown in the illustration, normal maintenance would include. Illustration MO-0074
Answer A: mechanically adjusting the valve at point "D"
Answer B: mechanically adjusting the valve at point "E"
Answer C: changing the tappet clearance as measured between points "A" and "B"
Correct Answer D: measuring the cold valve clearance between components "C" and "D"
33. (3.4.1.2.1-6) After testing your medium-speed engine's exhaust valve springs you find one with a spring constant that is lower than specified by design and a length that is reduced in length from that specified by design. What is the recommended course of action?
Answer A: Anneal spring to restore the spring constant to the original value.
Answer B: Restore the spring to its original length by stretching.
Answer C: Remove shims to restore spring to its original length.
Correct Answer D: Replace spring and check the valves cam and follower for marring caused by bounce.
 
34. (3.4.1.2.1-5) When a naturally aspirated four-stroke cycle diesel engine is converted for supercharging, which of the following changes must be made to the valve timing?
Correct Answer A: The intake valve opening is advanced and the exhaust valve closing is retarded.
Answer B: The intake valve opening is unchanged and the exhaust valve closing is advanced.
Answer C: The intake valve opening is retarded and the exhaust valve closing is advanced.
Answer D: The intake valve closing is retarded and the exhaust valve closing is advanced.
35. (3.4.1.3.5-3) While inspecting diesel engine combustion space components, which components would you consider for particular scrutiny for evidences of high temperature corrosion?
Answer A: Exhaust valves and seats, upper circumference of cylinder liner.
Correct Answer B: Exhaust valves, exhaust valve seats, piston crowns, cylinder heads and upper circumference of cylinder liners.
Answer C: High temperature corrosion does not effect these components.
Answer D: Undersides of cylinder heads, piston crown and exhaust valve.
 
36. (3.4.2.3-1) If an auxiliary diesel engine equipped with an electric starting system cranks very slowly after repeated attempts to start, the cause could be a/an.
Correct Answer A: overheated motor windings
Answer B: ring gear with broken teeth
Answer C: low lube oil viscosity
Answer D: low compression pressure
 
37. (3.4.2.3-8) High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be caused by.
Answer A: plugged fuel nozzle holes
Answer B: excessive compression pressure
Correct Answer C: engine overload
Answer D: low combustion temperature
38. (3.4.2.3-11) In a four-stroke cycle diesel engine, badly worn intake valve guides can cause excessive.
Answer A: cooling water temperatures
Correct Answer B: lube oil consumption
Answer C: exhaust pressure
Answer D: exhaust temperatures
 
39. (3.4.2.3-3) On small diesel engines, a noticeable decrease in the time interval between the replacement of the lube filter cartridge indicates.
Answer A: excessive oil temperature
Answer B: excessive oil pressure
Answer C: dirty air filter
Correct Answer D: piston ring blow-by
 
40. (3.4.2.1-6) In diesel engines, hydraulic valve lifters are used to.
Answer A: obtain greater valve lift
Answer B: create longer valve duration
Correct Answer C: reduce valve gear pounding
Answer D: increase valve operating lash
41. (3.4.2.1-7) The intake and exhaust valves used in a diesel engine are returned to their seats by
Answer A: combustion pressure
Answer B: push rod pressure
Answer C: exhaust pressure
Correct Answer D: spring force
 
42. (3.4.2.1-5) The part labeled "G", as shown in the illustration, is a. Illustration MO-0040
Answer A: connecting rod cap
Answer B: bearing shell
Correct Answer C: connecting rod bushing
Answer D: piston bushing
43. (3.4.2.1-4) When two cams of the same diameter, one with tangential flanks and the other with convex flanks are compared, the cam with tangential flanks will cause.
Answer A: less valve seat wear
Answer B: greater valve lift
Answer C: more abrupt valve action
Correct Answer D: less valve gear wear
 
44. (3.4.2.1-3) The valve cam slope angle determines the.
Answer A: engine fuel efficiency
Correct Answer B: acceleration rate of valve opening and closing
Answer C: diameter of intake and exhaust valves
Answer D: engine torque characteristics
 
45. (3.4.2.1-2) In the auxiliary diesel engine, shown in the illustration, the. Illustration MO-0006
Correct Answer A: governor is linked to the fuel injection pump by vertical linkage
Answer B: explosion relief doors are clearly visible on both sides of the crankcase
Answer C: camshaft rotates at the same speed as the crankshaft
Answer D: engine oil filter is outboard of the electric starter
46. (3.4.2.2-1) Before any auxiliary diesel engine hydraulic starting system is opened for servicing or repair, you must.
Correct Answer A: bleed off all hydraulic pressure from the system
Answer B: place all control levers in the 'HOLD' position
Answer C: block all hydraulic hoses using high-pressure covers
Answer D: ensure that the hydraulic fluid reservoir is full
 
47. (3.4.2.2 -3) In an auxiliary diesel engine, one reason for knurling the piston skirt is to.
Correct Answer A: improve skirt lubrication
Answer B: transmit forces evenly
Answer C: allow for heat expansion
Answer D: improve the piston seal
48. (3.4.2.2-2) The service life of a worn aluminum piston for an auxiliary diesel, for which no spares are readily available, can be extended by.
Correct Answer A: knurling the piston skirt surface
Answer B: increasing the dimensions of the ring land grooves
Answer C: building up the piston skirt with a liquid epoxy material and then remachining
Answer D: turning down the piston skirt to concentric values
 
49. (3.4.2.2-4) A four-stroke cycle auxiliary diesel engine fuel cam has shifted from its original position during maintenance. To ensure correct timing of the fuel pump, the intake and exhaust valves should be in what position when approaching top dead center for injection?
Correct Answer A: Intake and exhaust valves closed
Answer B: Exhaust valve open, intake valve closed
Answer C: Intake and exhaust valves open
Answer D: Intake valve open, exhaust closed
50. (3.4.3.1.4-2) The cylinders labeled "B" and "C" in the illustration are used to. Illustration MO-0125
Answer A: supply a specific volume of oil to the engine governor
Answer B: provide oil to lubricate component "F"
Answer C: provide the required quantity of grease at specified maintenance intervals
Correct Answer D: supply the force required to shift the engine camshafts axially to reverse engine rotation
 
51. (3.4.3.1.4-1) The component labeled "A" on the engine reversing device shown in the illustration, performs its function by transmitting. Illustration MO-0125
Answer A: a hydraulic pressure which shifts an alternate set of camshaft followers to ride on the engine camshaft
Answer B: an electric voltage which energizes solenoids to de-clutch the engine
Answer C: a fuel oil pressure signal which reverses the engine governor control cylinder
Correct Answer D: a pneumatic signal which activates a hydraulic control cylinder allowing the camshaft to shift axially
52. (3.4.3.1.3 -2) In order to reverse the rotation of a two-stroke cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the .
Answer A: piston cooling pumps
Correct Answer B: starting air and fuel pumps
Answer C: exhaust valves
Answer D: all of the above
 
53. (3.4.3.1.2-1) Which internal combustion engine starting system uses a vane type fluid motor?
Answer A: Jet flow
Answer B: Centrifugal
Answer C: Electric
Correct Answer D: Compressed air
54. (3.4.3.1.2 -5) Which of the following operating characteristics of the Bendix drive friction clutch is associated with a Bendix drive starter?
Answer A: Engages the pinion with the air start distributor.
Correct Answer B: Helps absorb the shock when the pinion engages the flywheel ring gear.
Answer C: Disengages the pinion from the flywheel ring gear.
Answer D: Prevents the pinion starter from overrunning on the starter shaft.
 
55. (3.4.3.1.2-6) The pinion of an auxiliary diesel-electric starting motor normally engages the flywheel ring gear by means of a/an.
Answer A: magnetic type coupling
Answer B: automatic follow-up
Answer C: muff coupling and release
Correct Answer D: Bendix drive or similar mechanism
56. (3.4.3.1.2-4) In a Bendix starter drive, the pinion engagement with the flywheel ring gear is initiated by.
Answer A: Bendix spring pressure
Correct Answer B: starter drive shaft rotation
Answer C: a differential spring
Answer D: solenoid throw out action
 
57. (3.4.3.1.2-2) Hydraulic starters are installed on many lifeboat diesel engines instead of comparable air start systems, because.
Correct Answer A: the system can be manually recharged
Answer B: the system does not require high-pressure piping
Answer C: hydraulic systems turn diesel engines at higher rates of speed than air starters
Answer D: hydraulic starters are the least expensive of all starting systems
58. (3.4.3.1.5-1) Intercoolers installed on starting air compressors, reduce the possibility of
Answer A: interstage vapor lock
Answer B: discharge pulsations
Answer C: dust entering the first stage
Correct Answer D: lube oil carbonization
 
59. (3.4.3.3.1-2) A pre-arrival test is being performed with the engine on bridge control. The vessel has a slow speed engine with mechanical starting air system (not electronic). After a stop order, the engine fails to restart in the next ahead direction order. What would be your immediate actions to restart the engine, if the order was still ahead?
Answer A: Inform the bridge that all are working on the problem and they may have to consider anchoring until the problem is resolved.
Answer B: Call the bridge and inform them of the problem. Ascertain that the main starting valve is open and functioning properly and start trouble shooting.
Correct Answer C: Inform the bridge. Take engine room control of the engine, change the engine's direction to astern position and try to restart in that position. When the engine tries to restart, switch back to ahead and restart.
Answer D: Call the bridge and inform them of the problem. Ascertain that starting air tanks are up to pressure and are lined up and start trouble shooting.
60. (3.4.3.3.1-3) During maneuvering on a slow speed diesel engine vessel, a low starting air system pressure alarm is activated. Local starting air receivers' pressure gauges indicate proper pressures, and compressors are running and are 'loaded' up. What could cause the alarm?
Answer A: Malfunctioning starting air cylinder distributor valves.
Answer B: A stuck open air starting valve on one of the engine cylinders.
Answer C: Malfunctioning, stuck open, main engine air starting valve.
Correct Answer D: Faulty system alarm pressure switch and/or a fault in the alarm circuit.
 
61. (3.4.3.1.1-2) During the starting of a diesel engine, compression gases are prevented from backing into the air starting system, shown in the illustration, by the. Illustration MO-0046
Correct Answer A: cylinder air starting check valves
Answer B: air starting control valve
Answer C: individual distribution valves
Answer D: high-pressure in the starting air manifold
62. (3.4.3.1.1-4) In a medium-speed marine propulsion engine equipped with direct admission air starting valves, the cylinders without air starting valves fire first because the.
Answer A: fuel is admitted only to these cylinders during cranking
Answer B: operation is under higher compression
Correct Answer C: cylinders are not chilled by the expansion of the starting air
Answer D: compression is released during starting by opening the exhaust valve
 
63. (3.4.3.1.1-1) Which of the following statements is true concerning the air starting valve, labeled ''IN'', as shown in the illustration? Illustration MO-0046
Answer A: When starting, the air starting valve is held open by air pressure.
Answer B: When starting air is secured, the air starting valve is closed.
Answer C: During normal engine running, the air starting valve opens and closes constantly due to cam action.
Correct Answer D: The air starting valve is opened by cam action.
64. (3.4.4.1.1-1) What type of engine lubrication oil filter system sends filtered oil directly to the high- pressure supply gallery?
Correct Answer A: shunt system
Answer B: batch system
Answer C: centrifugal purifier system
Answer D: bypass system
 
65. (3.4.4.1.2-2) The device shown in the illustration is a. Illustration MO-0008
Answer A: level type explosimeter, for small medium-speed, trunk type piston engines
Answer B: rotary type mist detector, designed for use in four-stroke, high-speed diesel engines
Correct Answer C: comparator type mist detector for large low-speed, crosshead type engines
Answer D: photoelectric, explosive gas indicator, for use in high-speed, two-stroke, trunk type piston engines
66. (3.4.4.1.2-3) The purpose of an oil mist detector in a main propulsion diesel engine is to warn of
Correct Answer A: a possible overheated bearing
Answer B: low cylinder oil pressure
Answer C: excessively high crankcase vacuum
Answer D: excessive carbon buildup in the lube oil
 
67. (3.4.4.1.2-1) The device shown in the illustration is classified as a/an. Illustration MO-0008
Correct Answer A: comparator type mist detector
Answer B: Ringelmann exhaust gas analyzer
Answer C: reflective type explosion meter
Answer D: exhaust gas vapor condenser
68. (3.4.4.1.3-4) The device shown in figure "A" of the illustration is used to. Illustration MO-0042
Answer A: admit starting air to the cylinder
Correct Answer B: provide lubrication to the cylinder
Answer C: inject fuel into the cylinder
Answer D: provide an adapter to obtain combustion pressure readings
 
69. (3.4.4.1.3-5) The illustrated device is used to. Illustration MO-0050
Correct Answer A: supply cylinder lubricating oil to the engine
Answer B: actuate exhaust valves in the correct sequence
Answer C: meter fuel oil to the injectors
Answer D: admit the correct amount of starting air to the cylinders in proper order
70. (3.4.4.1.3-3) The rate of cylinder lubricating oil metered to each cylinder of a large, low-speed, main propulsion diesel engine is.
Answer A: adjusted during each hour of operation while at constant RPM
Answer B: lower at sea than while maneuvering
Answer C: the same, whether at sea, or during maneuvering
Correct Answer D: reduced during periods of low load operation
 
71. (3.4.4.1.3 -1) One advantage of a vacuum feed sight glass indicator used on cylinder lubricators over the discharge side liquid filled type sight glass is .
Answer A: a lower grade of cylinder oil may be used
Answer B: adjustments are not required
Correct Answer C: better visual metering adjustment
Answer D: there are fewer moving parts
72. (3.4.4.1.3-2) Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are.
Answer A: operated manually once each hour
Correct Answer B: adjustable to meet lubrication requirements
Answer C: placed into operation only at maximum load
Answer D: operated until the engine has started
 
73. (3.4.4.2.1-1) A 'Blotter test' is a test performed on the lube oil of a diesel engine which can determine.
Answer A: the flash point of the oil
Answer B: the specific gravity of the oil
Answer C: the TBN number of the oil
Correct Answer D: a change in the oils viscosity
74. (3.4.4.2.1-3) If the analysis of used lube oil indicates a high content of iron particles, this could indicate.
Correct Answer A: excessive ring and liner wear
Answer B: inadequate air filtration
Answer C: excessive cooling of lubricating oil
Answer D: corrosive deterioration of a bearing
 
75. (3.4.4.2.1-4) A decrease in the flash point of diesel engine lube oil indicates the lube oil has become
Correct Answer A: diluted with fuel oil
Answer B: contaminated with sludge
Answer C: diluted with water
Answer D: contaminated with carbon
 
76. (3.4.4.2.1-2) Which of the following test indicators should be considered the most significant factor in determining as to whether or not a diesel generator's lube oil should be drained and renewed?
Answer A: The oil appears black in color.
Correct Answer B: An extremely high neutralization number.
Answer C: An extremely low precipitation number.
Answer D: An increase in flash point.
 
77. (3.4.4.3-9) Crankcase explosions in propulsion diesel engines result from.
Correct Answer A: the ignition of unburned fuel and air in the crankcase
Answer B: the dilution of crankcase oil with particles of combustion
Answer C: the splashing of lubrication oil by the crankshaft
Answer D: broken fuel lines spraying oil on the crankcase
78. (3.4.4.3-6) Which of the following effects will excessively cold lube oil have on the operation of a diesel engine?
Correct Answer A: The engine will crank slowly and may fail to start.
Answer B: The cooling system will overheat causing the engine to stall.
Answer C: The engine will overspeed when started.
Answer D: The fuel oil supply will become diluted resulting in rough running.
79. (3.3.4.3-7) Oil analysis for a crosshead type diesel engine indicates the TBN of the crankcase lubricating oil is increasing. This is most likely associated with which of the following?
Answer A: Excessive purification temperatures
Answer B: Increase in the water content of the crankcase lubricating oil
Correct Answer C: Leaking stuffing boxes introducing cylinder lubricating oil into the crankcase
Answer D: Bearing wear
 
80. (3.4.4.3-3) A dirty lube oil strainer can result in.
Answer A: excessive oil consumption
Answer B: low lube oil temperature
Answer C: crankcase dilution
Correct Answer D: low bearing oil pressure
81. (3.4.4.3-4) Lube oil in the fresh water cooling system of a diesel engine may result from a
Answer A: lube oil sump overflow
Answer B: camshaft seizure
Correct Answer C: lube oil cooler failure
Answer D: lube oil pump failure
 
82. (3.4.4.3-2) What could cause the bypass valve in a full-flow lubrication system to open?
Answer A: Bypass valve setting is too high
Answer B: Fuel dilution of the lubricant
Answer C: Check valve stuck open
Correct Answer D: Clogged filter element
 
83. (3.4.4.3-5) Oil oxidation, as a result of excessively high lube oil temperature, is harmful to a diesel engine because.
Answer A: lube oil viscosity is always decreased
Answer B: oil foaming will occur
Correct Answer C: corrosive by-products are usually formed
Answer D: large quantities of oil are consumed
 
84. (3.4.4.3-1) A bronze bearing liner with a lead-tin flashing has a milky-white color over most of its surface and some areas of exposed bronze. The white coloring indicates.
Correct Answer A: water contamination of the lube oil system
Answer B: proper break-in wear
Answer C: improper break-in wear
Answer D: relocation of the overlay flashing
 
85. (3.4.4.3-11) While underway, a slow-speed diesel engine lube oil sump level slowly begins to decrease. Which of the following should be checked?
Correct Answer A: The lubricating oil cooler for leakage into the cooling system.
Answer B: The standby lube oil pump to ensure it is not operating.
Answer C: The tank heating coils to ensure they are secured.
Answer D: The piston oil scraper rings for excessive wear.
 
86. (3.4.5.3-3) Heavy fuel oils generally have an upper average ash content of 0.1% by weight. Which of the following conditions could be expected if the ash content increases above this amount?
Correct Answer A: Increased exhaust valve wear
Answer B: Increased MEP
Answer C: Excessive bearing wear
Answer D: Glazing of the cylinder liners
87. (3.4.5.3-1) On a slow-speed, diesel-propelled vessel operating with constant slip, what is the effect on fuel consumption with an increase in shaft RPM?
Answer A: fuel consumption varies as the square of the shaft RPM
Answer B: fuel consumption varies directly proportional to the shaft RPM
Correct Answer C: fuel consumption varies as the cube of the shaft RPM
Answer D: fuel consumption varies inversely with the shaft RPM
 
88. (3.4.5.3-6) While bunkering heavy fuel, what quick/easy test can one perform onboard to determine the compatibility of 'old' with 'new' fuel?
Answer A: Take equal samples of both fuels, elevate their temperature, mix them vigorously. If no frothing occurs, they are compatible.
Correct Answer B: Use blotter paper with a single concentric drop of 'old' and 'new' fuel, if they do not form separate circles, the fuels may be deemed compatible.
Answer C: Mix two equal samples of the two fuels at elevated temperatures and determine if they become a homogeneous mixture.
Answer D: Perform a running viscosity test of both fuels, at the same temperature, if the viscosities are equal, they should be compatible.
89. (3.4.5.3-2) You are onboard a vessel with a slow-speed crosshead type engine. The fuel just received has a significantly lower sulfur content than the previous bunkers. Which of the following would be a concern due to the reduced sulfur content?
Answer A: Fuel injection temperature
Correct Answer B: Base number of the cylinder oil
Answer C: Fuel supply system pressure
Answer D: Purifier gravity disk size
 
90. (3.4.5.2-3) Does sulfur content of heavy fuel oil effect the fuel rate of a diesel engine and why or why not?
Answer A: No, it only effects possible acid corrosion of engine components.
Answer B: Yes, it may increase wear of engine components and thus piston ring blow-by.
Correct Answer C: Yes, high sulfur content decreases calorific value of fuel.
Answer D: No, it does not effect efficiency of combustion.
91. (3.4.5.2-2) Catalytic fines comprised of aluminum oxide and/or silicon dioxide are a common contaminant of residual fuels. Which diesel engine components would be most effected by catalytic fines in fuel?
Answer A: High pressure fuel pumps and cylinder liners.
Answer B: Fuel injectors and piston rings.
Correct Answer C: High pressure fuel pumps and fuel injectors.
Answer D: Fuel injectors and turbocharger blading.
 
92. (3.4.5.1-1) When is fuel injected into a cylinder of diesel engines?
Answer A: After combustion gases in the cylinder have expanded.
Answer B: As air is taken into the cylinder.
Correct Answer C: After air in the cylinder is compressed.
Answer D: Before air in the cylinder is compressed.
 
93. (3.4.5.1-8) Fuel combustion in a diesel engine cylinder should begin just before the piston reaches top dead center and should.
Answer A: end when fuel injection has been completed
Answer B: be completed exactly at top dead center
Answer C: end at bottom dead center
Correct Answer D: continue through the afterburning period
94. (3.4.5.1-5) The pressure in an operating diesel engine cylinder continues to rise for a short period after the piston passes top dead center as a result of the.
Answer A: fuel injection occurring at that point and combustion begins
Answer B: exhaust and intake valves just closing
Answer C: maximum compression pressure is just being attained
Correct Answer D: expansion during the combustion process
 
95. (3.4.5.1-4) The rate of pressure rise during the period following fuel ignition in a diesel engine is influenced by the length of the ignition delay period and the.
Answer A: volumetric efficiency
Correct Answer B: turbulence of the air charge
Answer C: fuel efficiency
Answer D: valve overlap
96. (3.4.6.1.3-2) The purpose of the interlocked three-way valve shown in the illustration is to . Illustration MO-0058
Answer A: control the rate of fuel oil flow to the engines
Correct Answer B: change fuel from heavy to light oil or vice-versa while insuring that oil is returned to the proper day tank
Answer C: act as an emergency fuel shut off, regardless of the fuel being used
Answer D: recirculate fuel through the heater during warm-up
 
97. (3.4.6.1.3-1) Heavy fuel oil used in the system shown in the illustration, will have the lowest viscosity . Illustration MO-0058
Answer A: at the transfer pump discharge
Answer B: in the settling tank
Answer C: in the three-way valve
Correct Answer D: at the main engine fuel oil header
98. (3.4.6.1.1-2) The greatest difference between the centrifuge bowl shown in the illustration and that of a tubular bowl, with straight, vertical, interior surfaces, is that the illustrated unit. Illustration MO-0012
Answer A: does not require a discharge ring when operated as a separator
Answer B: rotates at 1000 rpm slower than the old tubular bowl type
Answer C: rotates at 1000 rpm higher than the old tubular bowl type
Correct Answer D: is self desludging
99. (3.4.6.1.1-1) The temperature of the contaminated fuel oil fed to the centrifuge shown in the illustration should be. Illustration MO-0012
Answer A: 160F to 180F
Correct Answer B: 203F to less than 212F
Answer C: greater than 212F
Answer D: selected according to the oil's viscosity index
100. (3.4.6.1.1-6) What terminates the sludge discharge cycle of the device shown in the illustration? Illustration MO-0112
Answer A: The solenoid valve opens, directs high-pressure fluid into the closing chamber, and results in an upward movement of the sliding piston.
Answer B: The solenoid valve closes, reduces the water pressure to the paring chamber, and allows the spring force to move the sliding piston upward.
Answer C: The solenoid valve closes, allows the weight of the sliding piston to oppose the low water pressure, and moves it along the axis of the spindle.
Correct Answer D: The solenoid valve closes, allows the water in the opening chamber to bleed off through "S", and the sliding piston moves upward due to the force developed in area "J".
 
101. (3.4.6.1.1-5) The area indicated by the letter "W", shown in the illustration is correctly termed the . Illustration MO-0112
Answer A: upper sliding piston chamber
Answer B: closing chamber
Correct Answer C: opening chamber
Answer D: parting chamber
102. (3.4.6.1.1-4) The device labeled "D", as shown in the illustration, is the bowl. Illustration MO-0112
Correct Answer A: top
Answer B: hood
Answer C: hub
Answer D: cover
103. (3.4.6.3.2-1) During the change over period from residual to distillate fuel the final fuel filters clog at a decreasing time interval. What is the most likely cause?
Answer A: Gasification of the fuel in the fuel heater.
Answer B: Carbonization of the cylinder oil.
Answer C: Stratification of the fuel in the mixing tank.
Correct Answer D: Incompatibility of the fuels resulting in asphaltenes of the residual fuel precipitating out.
104. (3.4.6.3.2-2) What operational difficulties are associated with fuel incompatibility?
Answer A: Reduced rack settings.
Correct Answer B: Frequent clogging of final fuel filters and sticking/scuffing of fuel pump plungers and nozzles.
Answer C: Carbonization of the cylinder oil.
Answer D: Gasification of the fuel in the fuel heater.
105. (3.4.1.2 -5) A motor vessel has three centrifuges to pre-treat the fuel which can be configured to operate in series, parallel, and series-parallel. A large quantity of water is determined to be present in the fuel. How would you configure the centrifuges to deal with this problem?
Answer A: Run all three centrifuges as purifiers and decrease throughput.
Correct Answer B: Run two centrifuges in parallel as purifiers discharging to the third one in series as a clarifier.
Answer C: Increase 'shoot' cycles and run two centrifuges in series as purifiers.
Answer D: Drain settling and service tanks more often and run two centrifuges in series, purifier and clarifier.
 
106. (3.4.1.2-6) A motor vessel has two centrifuges to pre-treat fuel to the engine(s) which may be configured to operate in series or parallel. A large quantity of water has been determined to be present in the fuel. What actions would you take to minimize the effect of water prior to fuel injection?
Answer A: Run both centrifuges in series as purifiers and increase 'shoot' cycles.
Answer B: Maintain normal fuel oil throughput through both centrifuges functioning as clarifiers and increase the 'shoot' cycle of the two clarifiers.
Answer C: Drain settling tank(s) and service tank more often only, and monitor reduction in water content.
Correct Answer D: Run first centrifuge as a purifier in series with second as clarifier and reduce throughput and increase 'shoot' cycles'.
 
107. (3.4.6.1.2-1) Which of the following precautions should be taken prior to starting the separator shown in the illustration? Illustration MO-0127
Answer A: Check for the correct oil level in the gear housing.
Answer B: Make sure the separator is properly assembled.
Answer C: Release the bowl brake and confirm proper valve line up.
Correct Answer D: All of the above are correct.
 
108. (3.4.6.1.2-4) In pre-treating fuel oil on a motor vessel, what would you consider the most important factor to prevent high temperature corrosion on an engine's combustion components?
Answer A: Recycle the fuel between the settling tank(s) and service tank via centrifuges more than once.
Answer B: Monitor engine(s) exhaust temperatures more closely.
Correct Answer C: Run one centrifuge as a purifier at a reduced rate to minimize water, especially salt water, in the fuel.
Answer D: Drain settling tank(s) and service tank more often only.
 
109. (3.4.6.1.4-1) When changing over from residual to distillate fuel on a slow-speed diesel main engine, what is a good guideline to follow regarding the change over?
Answer A: Change over time should not be less than six hours.
Correct Answer B: Rate of temperature change of fuel to the engine should not exceed 2 degrees C per minute.
Answer C: Change over should be accomplished as quickly as possible as dictated by engine load.
Answer D: Change over time should not exceed two hours.
110. (3.4.6.1.4-2) When changing over from residual to distillate fuel on a slow-speed diesel propelled vessel, you should limit the rate of temperature change of the fuel in order to prevent what operational difficulty?
Correct Answer A: Seizing and scuffing of fuel pump plungers and injector needle valves due to thermal effects on close clearance components.
Answer B: Dezincafication of the fuel in the mixing tank.
Answer C: Surging/hunting of the governor due to rack sticking.
Answer D: Carbonization in the fuel heater.
 
111. (3.4.6.2.1-5) After removing the bowl hood of the device shown in the illustration, excessive quantities of sludge are visible. Which of the following statements represents the approach to rectify the situation? Illustration MO-0112
Answer A: Remove only the disc stack, separate all the discs, clean with steel wool and solvent, replace the disc stack ensuring it is located by use of the dowel pin shown.
Answer B: Disassemble the entire unit, clean all components, replace all defective discs and use the proper lubricant where required.
Answer C: Steam clean the components in place, check for proper alignment, using the match marks provided, reassemble and restart the unit.
Correct Answer D: Disassemble the entire unit, clean all components, replace any defective gaskets and use the proper lubricants where required.
112. (3.4.6.2.1 -3) Using the graph shown in the illustration, the oil being separated has a specific gravity of 0.87 kg/dm3 at 72.5C. What will be the specific gravity if the temperature is lowered to 40C? Illustration MO-0113
Answer A: 0.872 kg/dm3
Answer B: 0.882 kg/dm3
Correct Answer C: 0.892 kg/dm3
Answer D: 0.902 kg/dm3
 
113. (3.4.6.3.1-9) As Chief Engineer of a slow-speed diesel engine vessel equipped with an ALCAP fuel oil purification system. You note a definite increase in the rate at which the purifier sludge tank is rising. One of the first items to check on your system would be which of the following?
Correct Answer A: The opening water solenoid for leak through.
Answer B: The water transducer located in the dirty oil supply line.
Answer C: The RPM of the bowl.
Answer D: The voltage to the EPC control cabinet.
 
114. (3.4.6.3.1-14) Your ship is equipped with ALCAP heavy fuel oil purifiers. The watchstander reports excessive water drained from the fuel oil service tank. Which component should he check?
Answer A: The water transducer located in the dirty oil supply line.
Answer B: The bowl RPM.
Correct Answer C: The water transducer located in the clean oil discharge line.
Answer D: The closing water solenoid valve in the fresh water line.
115. (3.4.6.3.1 -8) Which of the following statements describes what will occur if the annular spaces, indicated by the letter "K" of the device shown in the illustration, became restricted? Illustration MO-0112
Correct Answer A: The bowl will fail to close when starting and the unit will not shoot when operating.
Answer B: The unit will not start due to pressure/time delay relays.
Answer C: The bowl will fail to close, but the unit will be capable of shooting while in operation.
Answer D: Operating water will be supplied through port "S".
 
116. (3.4.6.3.1-3) If item "F" begins leaking during operation, which of the following operating conditions will NOT occur? Illustration MO-0112
Answer A: The unit will not properly operate and should automatically shut down.
Correct Answer B: The oil/water interface will remain in the same neutral position.
Answer C: The oil/water interface will move outward from the vertical axis of the machine.
Answer D: The water seal will be lost.
 
117. (3.4.6.3.1-6) While operating the fuel oil centrifuge shown in the illustration, the fuel oil is being continuously ejected with the sludge and the seal water. The probable cause is the . Illustration MO-0012
Answer A: gravity disk inside diameter is too small
Correct Answer B: gravity disk inside diameter is too large
Answer C: back pressure is too low
Answer D: incorrect number of disks have been placed in the disk stack
 
118. (3.4.6.3.1-2) As shown in the illustration, which of the following conditions would be responsible for a "low-pressure in oil outlet" alarm to be indicated? Illustration MO-0127
Answer A: Controller setpoint changed
Correct Answer B: Throughput too low
Answer C: Emergency stop button not reset
Answer D: Separating temperature too low
 
119. (3.4.6.3.1-4) While operating the fuel oil centrifuge shown in the illustration, the bowl fails to open for sludge ejection. The probable cause is that. Illustration MO-0012
Correct Answer A: the seal ring on the operating slide is defective
Answer B: the operating water pressure is too high
Answer C: the bowl disk set is clogged
Answer D: one or more of the sludge ports is partially clogged
 
120. (3.4.6.3.1-5) When reassembling the bowl of the centrifuge, shown in the illustration, the alignment mark on the locking ring passes the bowl cover mark in excess of the manufacturer's specifications. This is due to. Illustration MO-0012
Answer A: the paring devices have been reinstalled in the wrong order
Answer B: too many disks being left out of the bowl during reassembly
Correct Answer C: excessive wear of the locking ring and/or bowl threads
Answer D: the disks have not been placed back in the bowl in numerical sequence
 
121. (3.4.6.3.1-12) On a slow-speed diesel engine vessel equipped with an ALCAP fuel oil purification system, what would be a symptom of an opening solenoid valve leaking by?
Answer A: An increase in RPM.
Correct Answer B: An increase in the rate at which the purifier sludge tank is rising.
Answer C: An increased in the voltage at the EPC control cabinet.
Answer D: An increased amperage draw.
 
122. (3.4.7.1.4-1) The component shown in the illustration would be identified as a. Illustration MO-0097
Answer A: slow speed engine cylinder liner lubricator
Answer B: centrifugal flyweight governor
Correct Answer C: slow speed engine fuel pump
Answer D: injector cooling system pump
123. (3.4.7.1.4-2) The component identified as item #15 is used to. Illustration MO-0016
Answer A: test injector popping pressure
Answer B: advance fuel pump timing
Correct Answer C: stop fuel delivery to the injector
Answer D: increase the fuel pump delivery pressure
 
124. (3.4.7.1.4 -4) According to the illustration, initial timing of fuel injection into the cylinder is controlled with the component that is identified as the letter. Illustration MO-0097
Correct Answer A: C
Answer B: H
Answer C: I
Answer D: K
125. (3.4.7.1.4-5) According to the illustration, fuel cutoff timing in the cylinder is controlled with the component that is identified as the letter. Illustration MO-0097
Answer A: C
Answer B: H
Correct Answer C: I
Answer D: K
126. (3.4.7.1.2-4) As shown in the illustration of the fuel injection pump, the component labeled "N" would be identified as the . Illustration MO-0061
Correct Answer A: Barrel
Answer B: Sleeve
Answer C: Control Rack
Answer D: Plunger
 
127. (3.4.7.1.2-5) As shown in the illustration of the fuel injection pump, the function of the area designated as "L" is to . Illustration MO-0061
Answer A: relieve excessive injector discharge pressure
Answer B: control the fuel injection rate
Correct Answer C: allow excess fuel oil to return to the fuel oil system
Answer D: provide for plunger lubrication
128. (3.4.7.1.2-6) In the illustration shown, moving the component labeled "E", further to the left, will result in. Illustration MO-0061
Correct Answer A: a shorter fuel injection cycle
Answer B: a greater quantity of fuel injected
Answer C: an increase in the cylinder mean effective pressure
Answer D: an increase in fuel pump delivery pressure
129. (3.4.7.1.2-2) Which of the following statements represents the function of the plunger flange labeled "A" shown in the illustration? Illustration MO-0061
Answer A: It prevents the plunger from rotating in the barrel.
Answer B: It limits the actual stroke of the plunger.
Answer C: It takes the plunger off stroke when injection is completed.
Correct Answer D: It transmits the control rack setting to the plunger.
130. (3.4.7.1.2-7) What is the purpose of the "window" installed in the housing of an individual jerk pump?
Answer A: To set up the fuel rack calibration in cubic millimeters.
Answer B: To check that fuel oil return passages are clear.
Answer C: To check for sludge on the pump barrel.
Correct Answer D: To allow the pump to be timed to the engine.
 
131. (3.4.7.1.1-2) Carbon deposit build up on the injection nozzle orifice is least likely to occur when using which type of fuel injector nozzle?
Answer A: Hole
Correct Answer B: Pintle
Answer C: Multi-pintle
Answer D: Multi-hole
132. (3.4.7.1.1-5) Which type of diesel engine fuel nozzle is shown in the illustration? Illustration MO-0059
Answer A: Open
Answer B: Pintle
Answer C: Self-cleaning
Correct Answer D: Multi-hole
 
133. (3.4.7.1.1-4) Regarding the fuel injector shown in the illustration, the purpose of piece #38 is to . Illustration MO-0059
Correct Answer A: filter the fuel
Answer B: adjust the fuel rack spring tension
Answer C: maintain fuel pressure at a preset level
Answer D: relieve excess fuel pressure to the suction side of the pump
 
134. (3.4.7.1.1-1) Differential needle valves used in fuel injectors are directly closed by.
Correct Answer A: spring force
Answer B: firing pressure
Answer C: cam action
Answer D: fuel oil pressure
135. (3.4.7.1.1-6) The amount of fuel delivered by a unit injector is controlled by the.
Answer A: engine speed
Answer B: main spring
Answer C: camshaft
Correct Answer D: rack position
136. (3.4.7.1.1-3) The item labeled #16 in the illustration is a stack of spring washers. Their function is to. Illustration MO-0062
Answer A: permit accurate stretch gauge measurement of bolt elongation during installation
Correct Answer B: maintain the same hold-down force on the injector regardless of varying engine operating temperatures
Answer C: prevent bolt failure by allowing limited movement of the injector when excessively high cylinder pressures are developed
Answer D: absorb the high-pressure pulses developed during the fuel injection process
 
137. (3.4.7.2-5) Which of the fuel nozzles listed requires the LEAST maintenance?
Answer A: Open
Answer B: Single hole
Correct Answer C: Pintle
Answer D: Multi-hole
138. (3.4.7.2-2) You are testing a closed fuel injection nozzle using a nozzle tester. A pressure slightly less than design valve opening pressure is applied. If no fuel appears at the spray tip, the
Correct Answer A: needle valve is operating properly
Answer B: nozzle orifices are too small
Answer C: needle valve spring is defective
Answer D: nozzle orifices are eroded
 
139. (3.4.7.2-4) Uneven bolt tightening during the installation of a fuel injection pump can result in
Answer A: high torsional shock to fuel lines
Answer B: ignition delay
Correct Answer C: binding of pump moving parts
Answer D: improper pump-to-engine timing
 
140. (3.4.7.2-3) Because of the close tolerances used in diesel engine fuel oil pumps, a worn plunger requires.
Correct Answer A: replacing the plunger and the barrel
Answer B: highly polishing both the plunger and barrel
Answer C: grinding the spare plunger to the barrel
Answer D: replacing plunger only
 
141. (3.4.7.3-1) Which of the following statements concerning the factors affecting ignition delay is correct?
Correct Answer A: An increase in coolant temperature will decrease ignition delay.
Answer B: An increase in intake air temperature will increase ignition delay.
Answer C: An increase in compression ratio will increase ignition delay.
Answer D: An increase in combustion chamber turbulence will increase ignition delay.
 
142. (3.4.7.3-8) High cylinder firing pressure, accompanied by low exhaust temperature, can result from.
Answer A: improper fuel rack positioning
Answer B: lengthy exhaust valve duration
Answer C: extended operation at light load
Correct Answer D: excessively early injection timing
143. (3.4.7.3-10) Heat damage to fuel injection nozzles can be prevented by avoiding_
Correct Answer A: long periods of engine overload
Answer B: metallic contact between nozzles and cylinder heads
Answer C: hard carbon deposit and varnish on the nozzles
Answer D: excessive fuel oil temperature
 
144. (3.4.7.3-6) Faulty operation of diesel engine fuel injection nozzles can be a direct cause of
Answer A: excessive fuel nozzle holder cooling
Correct Answer B: sediment in the fuel supply
Answer C: improper atomization of the fuel
Answer D: distortion of the fuel spray pattern
 
145. (3.4.7.3 -7) Which of the following problems is the main source of fuel pump and injection system malfunctions?
Answer A: Coated fuel lines
Answer B: Improper lubrication
Correct Answer C: Air in the fuel system
Answer D: Excessive vibration
 
146. (3.4.7.3-14) Surface irregularities, such as erosion and pitting on injection pump plungers, will
Correct Answer A: affect fuel oil metering
Answer B: affect engine performance at low-speed only
Answer C: disappear due to fuel oil abrasion
Answer D: increase ignition delay
 
147. (3.4.7.3-1 1) One cause of diesel engine surging can be a result of
Answer A: low compression
Correct Answer B: injection pump fuel rack binding or sticking
Answer C: solenoid stuck open
Answer D: fuel booster pump pressure too high
 
148. (3.4.7.3-15) While examining a used fuel injection nozzle(s), one finds worn and enlarged orifices. What does this indicate about that cylinder's performance prior to nozzle replacement(s)?
Answer A: Volume of atomization is increased, penetration is reduced, vaporization is increased, efficiency is not effected.
Answer B: Volume of fuel injected is increased, reduced injection pressure, decreased ignition delay.
Correct Answer C: Reduced combustion efficiency, increased ignition delay, reduced atomization, prolonged penetration.
Answer D: Penetration is increased, air/fuel mixture is increased, cylinder efficiency is not substantially effected.
 
149. (3.4.7.3-2) Injection lag in a diesel engine may be caused by.
Correct Answer A: the flexibility of high-pressure fuel lines
Answer B: a decrease in the air temperature
Answer C: a decrease in compression pressure
Answer D: a change in the cetane number of the fuel
 
150. (3.4.7.3-9) Problems with the diesel engine fuel injection pump are usually caused by
Answer A: kinked fuel lines
Answer B: excessive engine vibration
Answer C: improper adjustment
Correct Answer D: contaminated fuel
151. (3.4.7.3-12) In the common rail system, excessive pressure in the header may be caused by
Answer A: a malfunctioning injection nozzle
Answer B: insufficient leakoff through injection nozzle packing
Correct Answer C: improper adjustment of the bypass valve
Answer D: a dribble in the fuel injection nozzle
152. (3.4.7.3-3) Poor combustion in a diesel engine can be caused by
Answer A: high scavenge air pressure
Answer B: low exhaust pressure
Correct Answer C: low compression temperature
Answer D: high compression pressure
 
153. (3.4.8.1-9) The diesel engine shown in the illustration, is provided with an auxiliary blower to . Illustration MO-0003
Answer A: maintain a positive pressure on the crankcase
Answer B: increase scavenge air pressure at full load
Answer C: maintain a vacuum on the crankcase
Correct Answer D: provide scavenge air pressure at low load
154. (3.4.8.1 -8) In a two cycle diesel engine, a Roots-type blower is usually .
Correct Answer A: gear driven by the engine
Answer B: driven by separate motor
Answer C: actuated by the intake valves
Answer D: driven by an exhaust gas turbine
 
155. (3.4.8.1-1) Which of the following devices will increase the power output of a diesel engine without increasing its frictional load?
Answer A: Gear-driven centrifugal blower
Correct Answer B: Turbine-driven centrifugal blower
Answer C: Roots-type rotary blower
Answer D: Positive displacement blower
 
156. (3.4.8.1 -2) Clearance volume scavenging in a turbocharged, four-stroke cycle diesel engine is accomplished.
Answer A: with only the exhaust valve open
Answer B: without cooling the cylinders or pistons
Answer C: at a pressure below atmospheric
Correct Answer D: during the valve overlap period
 
157. (3.4.8.1-12) A loop or cross scavenged engine utilizes the motion of its pistons and a turbocharger to provide scavenging air. Which of the listed mechanical designs prevents the air under the pistons from being pumped back through the scavenge ports during the piston power stroke?
Answer A: Positive pressure from the blower
Answer B: Masked intake ports
Correct Answer C: Length of the piston skirt
Answer D: Lower liner seals
 
158. (3.4.8.3-1) Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the.
Answer A: compression pressure being greatly reduced
Answer B: air charge density becoming too high
Correct Answer C: formation of excessive quantities of condensate
Answer D: piston crown surfaces becoming too cold
159. (3.4.10.2-1) Which of the couplings listed is normally not repairable, and is usually replaced if completely damaged?
Answer A: Flexible disk-ring coupling
Correct Answer B: Gear-type coupling
Answer C: Block and jaw coupling
Answer D: Grid spring coupling
160. (3.4.10.2-2) When installing the bearing cap on the device shown in the illustration, which of the precautions listed must be observed? Illustration MO-0121
Answer A: Prior to installing the cap, position the thrust shoes in their proper locations.
Answer B: If the device is covered with abrasive material or contaminates, the unit may be reassembled, provided an abnormal method of reassembly is followed.
Answer C: After applying anti-seize to the external threads, torque one side at a time to the appropriate values using a quality torque wrench.
Correct Answer D: Once the bearing cap is properly torqued, measure the end gap dimensions to ascertain even tightening of the cap.
 
161. (3.4.10.2-3) What is the maximum allowable clearance permitted between the bearing, shown in the illustration and the shaft along its vertical axis? Illustration MO-0121
Answer A: 0.30 mm
Answer B: 0.46 mm
Correct Answer C: 0.80 mm
Answer D: 1.00 mm
162. (3.4.10.2-4) What is the normal bearing clearance permitted at the horizontal axis of the shaft for the bearing shown in the illustration? Illustration MO-0121
Answer A: The tolerances established are dependent on machining processes used and will vary amongst manufacturers.
Correct Answer B: The normal play on both sides of the shaft will be one tenth of a millimeter.
Answer C: The clearance on one side of the shaft at the axis will be one twentieth of a millimeter.
Answer D: The clearance is determined by the thickness of the hydrodynamic wedge formed and is not usually measured while underway.
 
163. (3.4.10.2-5) After following the prescribed procedures to measure the thrust bearing clearance shown in the illustration, the distance "F" is determined to be 200 mm, and 'f1' is 2.3 mm. Which of the following statements describes the condition indicated by these dimensions? Illustration MO-0121
Answer A: The loading ratio, or shaft diameter divided by collar surface area is within 2.7:1.
Answer B: These dimensions indicate the presence of flourishing marks on the thrust shoes; the marks becoming visible as the distance at 'f1' increases.
Correct Answer C: It is possible for the shaft to move axially 2.3 mm during astern operation and relates to an excess movement of 1.3 mm, 0.3 mm beyond the maximum worn play.
Answer D: The total active thrust area is 202.3 mm, well within the standards set forth by the GSMA (German Society for Machining Accuracy).
 
164. (3.4.10.3-1) When an additional load is applied to a diesel engine which is using an inadequately inflated air bladder clutch unit, you can expect.
Answer A: excessive wear on the thrust bearings
Answer B: pneumatic seizure
Answer C: chipped reduction gear teeth
Correct Answer D: overheating because of slipping shoes
 
165. (3.4.10.3-2) Misalignment of the drive shaft and propeller shaft flanges can be detected by using a dial indicator or.
Answer A: inside micrometer
Answer B: sighting device
Correct Answer C: feeler gage
Answer D: adjustable trammel
 
166. (3.4.10.3-3) The gear drive, shown in the illustration, can have the backlash determined best by using a. Illustration MO-0091
Answer A: lead wire
Answer B: red dye indicator
Correct Answer C: feeler gauge
Answer D: lash indicator
 
167. (3.4.10.3-4) The thrust bearing shown in the illustration has over eight years of ahead running time. Measurements show "i1" is 4 mm and "i2" is 1mm. Which of the following conditions is indicated and what steps should be taken, if any? Illustration MO-0121
Answer A: The stops in which the thrust bearing block rides are worn, and it is necessary to return these to their original specifications.
Correct Answer B: No appreciable wear has occurred, and the proper maintenance procedures should continue to be followed.
Answer C: A wear rate of 1.6 mm per year is excessive and requires immediate assistance from the manufacturer's field support.