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 ...

In this transitional period between the gasoline and electric ages, there's still plenty of room, and plenty of motivation, for last-gasp improvements to the combustion engine – and a Swiss R&D ...

Fittings such as these, for connecting a compressed air line to the spark plug hole for valve support, are available at most auto parts stores. Occasionally it is necessary or desirable to inspect or ...

Performance tricks are usually just sleight-of-hand changes that dolittle to improve performance. After all, if it was that easy, everyonewould be doing it, right? But the simple fact is, valvespring ...