A small gap with big importance in the performance and health of an engine - here's everything you need to know.

For mild street engines, stock valve springs are more than adequate. But if you've screwed in a big bumpstick for strip-banging or banzai runnin', then pay attention. Our plan was simple: Install a ...

Q:I have a 327 in my '31 Ford that features nearly the same cam and components as the one you referenced recently in Pit Stop (Nov. '12). Since a 1.6:1-ratio rocker arm will push the valve a little ...

American publisher Charles Knight was not at all impressed with his new 1901 Knox ‘gasoline runabout’. Like some other cars of the era, its four-stroke engine relied on a single valve to permit both ...