The space above the piston is now sealed due to the inlet valve closing and the exhaust valve having already closed.

由于进气门关闭、排气门也已关闭，现在活塞上部的空间被密封了。

youdao

But like the inlet valve, the exhaust valve needs time to reach the full-open position, it also needs time to reach the full-closed position.

但是像进气门一样，排气门需要时间到达充分打开和关闭的位置。

youdao

But like the inlet valve, the exhaust valve needs time to reach the full-open position, it also needs time to reach the full-closed position.

但是像进气门一样，排气门需要时间到达充分打开和关闭的位置。

youdao