An engine that just doesn't perform as it should at high speed on the dyno or racetrack can induce a series of checks that usually first includes measuring the pressure and volume of the fuel being ...

Engine performance is like a complicated formula in which each individual part plays a role in the final answer. Some parts of the formula affect the final outcome more than others. The valvetrain ...

If the LS1/LS2/LS6 engine family has a shortcoming, it has to be the rocker arm mounting, which doesn't allow for adjustment. Non-adjustable rockers have become standard in virtually all late-model ...

GM has filed a patent application a variable displacement valvetrain system with rocker shaft porting and insert sleeves for engine cylinder deactivation. The patent application is tagged with patent ...

The debate over the optimum rocker arm ratio has dragged on since the invention of the pushrod V-8. Even though Chevrolet made the decision easy for us when it engineered the small-block to run around ...

A recently filed patent details a new GM cylinder deactivation system that appears to be heading to the next-gen V8 engines coming in the 2027. This new GM cylinder deactivation system might replace ...

Q I own a '99 Chevy Lumina with a 3.1-liter V6. This weekend I got a flashing check-engine light with a severe misfire. I took the vehicle to a shop, which told me I had two rocker arms blown right ...