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 ...

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 ...

Those wound-up pieces of high-tensile steel under your rocker arms work so hard closing your valves over millions of cycles that they could probably use a replacement right about now. We're talking ...

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 ...

A STUDY of the influence of vibration on valve-springs reveals two possible ways in which a valve-spring can vibrate: First, when the frequency of the forced vibration is low, the force tending to ...

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 ...