Many diesel engine exhaust valves are being constructed with hollow stems filled with sodium in order to ()
单选题
2022-05-23 06:35
A、provide added wear protection against today’s corrosive quality of fuel
B、increase overall valve strength due to the high gas pressures
C、assist in dissipating heat due to the extreme operating temperatures
D、reduce the overall weight of the valve thus helping eliminate valve spring surge and hammering