单项选择题
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
The upper section of a piston is called the （）A.landB.s...
单项选择题The upper section of a piston is called the （）
A.land B.skirt C.crown D.plate
