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 ...

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 ...