In a four stroke engine, which process lasts the longest period?（）

A、exhaust and suction process

B、suction and compression process

C、combustion and exhaust process

D、working and exhaust process

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更多“In a four stroke engine, which process lasts the longest period?（）”相关的问题

第1题

[单选题] The size of the exhaust valve opening is （）

A、most critical in a four-stroke cycle diesel engine B、most critical in a two-stroke/cycle diesel engine C、most critical in a four-stroke/cycle diesel engine if it is turbocharged D、of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine

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第2题

[单选题] Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because（）.

A、The direction of pressure on the journal in four-stroke engine is continuously B、positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine C、four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines D、Low-stroke engines usually consume less lube oil than four-stroke engines

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第3题

[单选题] In diesel engines, the four basic events (intake, compression, power and exhaust) are performed once in （）.

A、two crankshaft revolutions in a two-stroke/cycle engine B、two power strokes in a two-stroke/cycle engine C、one power stroke in a two-stroke/cycle engine D、two piston strokes in a two-stroke/cycle engine

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第4题

[单选题] In four strokes engine, the cycle of events is completed in four strokes of （）.

A、the cylinder B、the crankshaft C、the piston D、the cross-head

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第5题

[单选题] 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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第6题

[单选题] The four-stroke cycle is so called because it takes （） to complete the processes needed to convert the energy in the fuel into work.

A、two strokes of the piston B、four strokes of the piston C、one revolution of the crankshaft D、four revolutions of the crankshaft

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第7题

[单选题] 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、bearing pressure in a four-stroke\cycle acting single diesel engine is continually reversed B、bearing pressure in a two-stroke\cycle single acting diesel engine is continually reversed C、the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine D、two-stoke/cycle diesel engines require more complicated lubrication piping