As engine rpm increases，there is less time for each step of the four-stroke cycle.
As engine rpm increases，there is less time for each step of the four-stroke cycle.
当引擎转速增加，四冲程循环每一步的时间变得越短。
As engine rpm increases，there is less time for each step of the four-stroke cycle.
当引擎转速增加，四冲程循环每一步的时间变得越短。