GM has filed a patent application a variable displacement valvetrain system with rocker shaft porting and insert sleeves for ...

General Motors has filed a new patent that offers a look at how the company may be rethinking cylinder deactivation for its ...

It's no big revelation that high-lift rocker arms (those with a greater multiplication ratio than stock rocker arms) generally increase the performance of an engine without necessitating a camshaft ...

Over the past couple of racing seasons, the camshaft specialty companies have created dozens of new profile designs, many of which are over the .800-inch-lift mark. Along with camshaft and cylinder ...