单项选择题
In a diesel engine, excessive cylinder liner wear will cause （） Ⅰ.increased blow-by Ⅱ.wear between the piston ring and groove
A.Ⅰonly is correct B.Ⅱ only is correct C.both Ⅰ and Ⅱ are correct D.neither Ⅰ or Ⅱ are correct
If the operating element of a thermostatic valve instal...
单项选择题If the operating element of a thermostatic valve installed in a diesel engine cooling system malfunctions, it may result in （）
A.a low level in the engine expansion tank B.excessively high coolant pressure C.improper temperatures D.malfunctioning of the jacket water heater
Why is the ring belt narrower in diameter than the skir...
单项选择题Why is the ring belt narrower in diameter than the skirt of a piston designed for a diesel engine?（）
A.To allow for greater expansion due to higher operating temperature B.To seal the cylinder against leakage of combustion gases C.To provide an additional surface for oil cooling D.To provide an additional strength for the crown and lower structure
The effective pump stroke of an individual port-and-hel...
单项选择题The effective pump stroke of an individual port-and-helix fuel injection pump is determined by the （）
A.fuel delivery pressure B.pump plunger diameter C.plunger control rack position D.total pump stroke
