A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) scavenging air is cooling the exhaust gases (2) exhaust cycle time is longer

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• In the cylinder head of a two-stroke/cycle diesel engine, valves are used for（）

  A . air intake B . a fuel outlet C . cooling water inlets D . exhausting combustion ga

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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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• What color exhaust will be exhibited when a slow speed two-stroke/cycle main propulsion diesel engine, designed to operate on light and heavy fuel oil, is operated on insufficiently preheated heavy fuel oil?（）

  A . White B . Black C . Blue D . Clear

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• A possible cause for an individual piston to knock when at TDC on a slow-speed, two-stroke/cycle main propulsion diesel engine could be due to （）

  A . early fuel injection B . excessive bearing play within the running gear C . overloading of the cylinder D . all of the above

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• A six-cylinder, two-stroke/cycle diesel engine is fitted with a rotary distributing air starting systemThe speed of the rotating distributor disc is （）

  A . one-half engine speed B . the same as engine speed C . twice engine speed D . four times engine speed

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• The process of scavenging a two-stroke/cycle diesel engine serves to（）

  A . improve fuel flow volume B . cool the exhaust valves C . reduce the intake air charge density D . increase the temperature of exhaust gase

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• A supercharged diesel engine when compared to a similar naturally aspirated diesel engine, will develop an increase in （）

  A . ignition lag B . engine horsepower C . lube oil system pressure D . specific fuel consumptio

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• One of the differences between a two-stroke engine and a four-stroke engine is,（）

  A . a two-stroke engine can’t work without cylinders B . a two-stroke engine can’t work without pistons C . a two-stroke engine can’t work without crankshafts D . a two-stroke engine can’t work without a blower

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• 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（）

  A . has little or no internal friction B . has a lower effective compression ratio C . operates with scavenge air under a positive pressure D . operates without energy absorbing intake and exhaust stroke

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• A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) MEP is lower and the scavenging air is cooling the exhaust gases (2) valve overlap in a four-stroke

  A . (1) only is correct B . (2) only is correct C . both (1) and (2) are correct D . Neither (1) or (2) are correct

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• Exhaust gases are generally removed from the cylinders of a two-stroke/cycle diesel engine by（）

  A . natural aspiration B . masked intake valves C . air cells D . scavenging air

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• Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of （）

  A . less even torque B . higher cylinder head temperatures C . fewer power strokes per revolution D . greater weight/size requirement

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• In a single acting, two-stroke/cycle, diesel generator engine, the power impulse in an individual cylinder occurs （）

  A . once every crankshaft revolution B . once every two crankshaft revolutions C . once every piston stroke D . twice every piston stoke

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• The exhaust gases in a supercharged two-stroke/cycle diesel engine are expelled from the cylinder by （）

  A . pumping action of the piston B . pressure of the fuel charge C . vacuum developed in the manifold D . pressure of the fresh air charge

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• The two strokes of a two-stroke/cycle diesel engine are （）

  A . power and intake B . intake and exhaust C . exhaust and compression D . compression and power

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• If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately（）

  A . the same indicated horsepower as a four-stroke/cycle engine B . twice the indicated horsepower as a four-stroke/cycle engine C . one half indicated horsepower as a four-stroke/cycle engine D . one power stroke for every two crankshaft revolutio

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• Large, two-stroke/cycle, main propulsion, diesel engine cylinders can be successfully pressure charged during normal operation, by using the （）.

  A . exhaust gas temperature system B . exhaust load system C . constant or pulse pressure system D . constant volume system

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• Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because （）

  A、a circulating system; a total loss system B、a total loss system; a circulating system C、an opened system; a closed system D、a closed system; an opened system

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• When inspecting piston rings through the ports of a two-stroke/cycle diesel engine, black areas on the sealing surfaces are the result of （）

  A . insufficient lubrication B . improper piston cooling C . blow-by D . overload operatio

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• A large two-stroke/cycle direct reversing diesel engine is to be reversedPrior to the admission of starting air you must （）

  A . line up the engine fore restarting with light diesel oil B . reposition the fuel injection cam C . change the intake and exhaust valve cam positions D . place the starting cam in the intermediate positio

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• Which of the two events listed occurs simultaneously in a two-stroke/cycle diesel engine?（）

  A . Exhaust and scavenging B . Scavenging and compression C . Ignition and expansion D . Exhaust and compressio

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• In a two-stroke/cycle diesel engine, the exhaust gases are expelled from the cylinder by the（）

  A . exhaust manifold B . valve bridge C . pressure of the fresh air charge D . valve adjusting gear

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• In order to keep excess oil from the intake ports in two-stroke/cycle diesel engines, ________.

  A.wide compression rings are used B.oil rings are located above the piston C.chromium plating is used on all piston rings D.oil rings are located near the bottom of the piston skirt

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