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 ...

Performance is all about pushing the envelope. As camshafts become more aggressive in the search for more power, these lobes make life increasingly difficult for valvesprings. This may seem like a ...

Does your engine need a valve adjustment? It depends on the age, condition and brand of vehicle you’re driving. Due to the popularization of roller-follower valve train designs that reduce friction ...

Obviously, these valve-control-related issues, associated with insufficient valvespring pressure, are the reason why camshaft manufacturers offer valvespring upgrades. The obvious answer might seem to ...

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 ...

American publisher Charles Knight was not at all impressed with his new 1901 Knox ‘gasoline runabout’. Like some other cars of the era, its four-stroke engine relied on a single valve to permit both ...