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 ...

If the cylinder heads are on the engine, you will need to add air pressure to the cylinder to hold the valves in place. Our example is the Craftsman 47089 compression test kit using the 14mm long ...

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 ...

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 ...

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 ...

In this installment of Weekly Boiler Tips we cover the safest testing frequencies and what you need to know before pulling that lever. May 21, 2025 Testing a relief valve at the wrong time could ...