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In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?()
A . noise coming from that air starting valve
B . continuous operation of the starting air compressor
C . zero air pressure in the air starting system
D . overheated starting air pipe to the cylinder head
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Which of the following conditions is realized by the turbo-charging of a previously naturally aspirated diesel engine?()
A . Ignition lag increases
B . Lube oil system pressure increases
C . Brake specific fuel consumption increased
D . Mechanical efficiency increaded
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Which of the following statements is correct for the design and installation of diesel engine cooling water systems?()
A . An alarm device with audible and visible signals is required for all cooling water systems
B . Propulsion engines with bores over 200 mm are to be fitted with cooling water jackets
C . Each totally enclosed cooling system shall be provided with a suitable head tank
D . Drain cocks are to be provided at the lowest points of all cylinder water jacket
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Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?()
A . In a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greater
B . Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the ports
C . No gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engine
D . The gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine
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Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?()
A . compression must be low for effective spark ignition
B . compression must be low for required horsepower and torque generation
C . compression must be low to prevent pre-ignition
D . compression must be low to have effective pre-ignitio
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Which lubricating oil additive is used in diesel engines to reduce the tendency for sludge and varnish to form on the engine parts?()
A . Flash point improvers
B . Pour point improvers
C . Inhibitors
D . Foam suppressor
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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 reversing the engine rotation?()
A . Flywheel inertia
B . Admission of starting air
C . The way of the vessel
D . securing of fuel to the cylinder
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On a turbo-charged, medium-speed diesel engine, which of the following problems is an indication of a restricted air intake passage?()
A . Engine is hard to start
B . Engine misses
C . Surges at governed RPM
D . Coolant temperature is too low
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A device which functions to bring a diesel engine to a full stop to protect it from damage is known as a/an ()
A . torque limiter
B . over-speed trip
C . over-speed governor
D . load limit governor
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If a diesel engine runs roughly, which of the systems listed is most likely to be at fault?()
A . Fuel
B . Lubricating
C . Cooling
D . Ignitio
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A diesel engine is supercharged in order to()
A . lower the no-load RPMs
B . provide more air for combine with the fuel
C . increase the no-load RPMs
D . provide more fuel combine with the air
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Which of the following methods is normally used to lubricate bearings in a small high-speed diesel engine?()
A . Splash lubrication
B . Pressure lubrication
C . Sight feed lubricators
D . Mechanical lubricator
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The diesel engine is a type of ().
A、A. turbine engine
B、B. gas turbine
C、C. steam engine
D、D. internal combustion engine
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Which of the combustion parameters listed is used in a diesel engine, but NOT related to the injection system?()
A . Atomization
B . Metering
C . Effective stroke
D . Penetratio
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Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is()
A . a combination of constant volume and constant pressure
B . a combination of constant temperature and constant pressure
C . entirely constant pressure
D . entirely constant volume
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With respect to diesel fuel, the ease with which a cold engine will start is dependent upon the()
A . ignition quality of the fuel
B . high heating value of the fuel
C . amount of carbon residue after combustion
D . internal flow resistance in the injector
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A diesel engine is similar to a gasoline engine except that the former has no ().
A . cross-head
B . cylinder
C . connecting rod
D . spark plug
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In a diesel engine, an integral liner is one in which the cooling water () Ⅰ.flows through the cylinder liner jackets Ⅱ.touches the outer side of the liner
A . Ⅰ only
B . Ⅱ only
C . both Ⅰ and Ⅱ
D . neither Ⅰ and Ⅱ
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The diesel engine is a type of internal combustion engine which ignites the fuel by injecting it into hot, high pressure air in a ().
A . air bottle
B . air compressor
C . crank case
D . combustion chamber
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Which of the following conditions is most likely to occur when unburned fuel contaminates the crankcase of a diesel engine?()
A . Lube oil is diluted and its viscosity is reduced
B . Sulfuric acid is formed
C . Bearings become pitted ad immediately fail
D . Valve stems develop sludge deposit
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Which of the listed diesel engine systems is likely to create the problem of a cylinder regularly misfiring?()
A . Lubrication
B . Cooling
C . Fuel
D . Electric ignitio
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Which of the following statements is correct concerning diesel engine cooling water systems?()
A . Each engine must have its own engine driven cooling water pump capable of providing cooling for all ranges of operation
B . propulsion engines with bores exceeding 200 mm are to be fitted with a means to display the cooling water temperature of each cylinder
C . At least two independent sea suctions are to be provided for supplying water to the engine jackets or to the heat exchangers
D . Suitable strain are to be fitted between the circulating pumps and heat exchangers when sea water is used for direct cooling
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The main operating characteristic of diesel engines which distinguishes them from other internal combustion engines is the ()
A . method of supplying air
B . cooling system
C . method of igniting fuel
D . valve operating mechanism
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With respect to diesel fuel, the ease with which a cold engine will start is dependent upon the__________
A.ignition quality of the fuel
B.high heating value of the fuel
C.amount of carbon residue after combustion
D.internal flow resistance in the injectors