更多"For an ordinary four-stroke engine "的相关试题:
[单项选择]In an engine with air inlet valve and exhaust valve on its cylinder heads the fresh air will enter into the cylinder （） and the gases exhaust （）, there being an adequate overlap between the inlet opening and the exhaust closing.
A. downwards；upwards
B. upwards；downwards
C. downwards；downwards
D. upwards；upwards
[单项选择]Worn diesel engine intake valve guides can result in （）
A. increased engine breathing efficiency
B. excessive valve lash
C. excessive lube oil consumption
D. lower than normal fuel consumption
[单项选择]Diesel engine valve springs function to （）
A. hold the valves open
B. keep the valves off their seats until the exhaust stroke is completed
C. close the valves
D. open inlet valves when the air injection cycle begins
[单项选择]The diesel engine valve subjected to most severe conditions of service is the （）.
A. cylinder exhaust valve
B. air starting valve
C. air inlet valve
D. cylinder relief valve
[单项选择]Diesel engine air start valve timing is controlled by（）
A. engine operating speed
B. an air manifold
C. a hydraulic distributor
D. individual cams and valve gear
[单项选择]In an ordinary diesel engine the fuel injection begins （）
A. after TDC
B. before TDC
C. after BDC
D. before BDC
[单项选择]For an ordinary four-stroke engine the exhaust valves open （）.
A. after TDC
B. before TDC
C. after BDC
D. before BDC
[单项选择]In an ordinary four-stroke engine the exhaust valves open （）
A. after TDC
B. before TDC
C. after BDC
D. before BDC
[单项选择]For an ordinary four-stroke diesel engine the exhaust valves close （）.
A. after TDC
B. before TDC
C. after BDC
D. before BDC
[单项选择]Exhaust valve openings in a diesel engine cylinder head are made as large as practical to （）
A. increase back pressure during the exhaust process
B. facilitate periodic replacement of the valves
C. reduce the pumping loss associated with scavenging
D. reduce tension on valve springs
[单项选择]Excessive valve lash in an auxiliary diesel engine will cause the valves to open（）
A. later and close sooner
B. sooner and close later
C. sooner and close sooner
D. later and close later
[单项选择]For an ordinary modem marine four-stroke engine the inlet valves close （）.
A. after TDC
B. before TDC
C. after BDC
D. before BDC
[单项选择]If the relief valve on a diesel engine cylinder lifts, the cause could be due to （）
A. liquid in the cylinder
B. low compression in the cylinder
C. high exhaust temperature
D. poor fuel penetration
[单项选择]If the valve tappets in a diesel engine are set at greater clearances than those specified by the engine manufacturer, those valves will （）
A. open late and close early
B. open late and close late
C. fail to open when the engine is cold
D. fail to open at normal operating temperature
[单项选择]Increasing the valve clearance between a valve stem and rocker arm, will result in the valve （）
A. closing later
B. opening sooner
C. staying open for a shorter period of time
D. staying open for a longer period of time
[单项选择]The needle valve in a fuel valve will （） when the fuel pressure action on the needle valve tapered face exerts a force lower than that of the spring compression.
A. be jammed
B. be opened
C. be seated
D. be broken
[单项选择]The temperature difference between the inlet and outlet temperature of the lube oil cooler in the lubricating system for the diesel engine is generally between （）.
A. 8-10℃
B. 10-12℃
C. 10-15℃
D. 10-20℃
[单项选择]Pressurized air enters the cylinder via the inlet ports and pushes the remaining exhaust gas from the cylinder in a process known as “（）”.
A. charging
B. super charging
C. scavenging
D. exhausting
[单项选择]An increased differential between the inlet and outlet of a strainer usually indicates the strainer is （）
A. holed
B. fouled
C. clean
D. dry
