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 ...

"Coil bind" occurs when a spring's coils stack solid at or before full camshaft lift. This develops an infinite load on the valvetrain, causing its weakest link to fail. If you're lucky, the result is ...