Grinding valves would require several more hours. These various times are mentioned because an engine that requires cylinder refinishing is usually in need of a general overhaul and these other services will also be required.

• 磨削气门则需要更多的时间。这里之所以提供几种不同的时间,是因为需要整修气缸的发动机通常必须进行大修,那么这些维修工作也就必不可少。