The exhaust valve opens before bottom dead
题型:单项选择题
问题:
The exhaust valve opens before bottom dead center in a four stroke engine to()
Ⅰ.allow for blow down
Ⅱ.Reduce pumping losses
A.Ⅰ only
B.Ⅱ only
C.both Ⅰ and Ⅱ
D.neither Ⅰ nor Ⅱ
The exhaust valve opens before bottom dead center in a four stroke engine to()
Ⅰ.allow for blow down
Ⅱ.Reduce pumping losses
A.Ⅰ only
B.Ⅱ only
C.both Ⅰ and Ⅱ
D.neither Ⅰ nor Ⅱ