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 ...

A recently filed patent details a new GM cylinder deactivation system that appears to be heading to the next-gen V8 engines ...

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 ...

One of the most common valvetrain upgrades for pushrod-style engines is roller rocker arms, which are often said to increase horsepower through reducing friction. But is it true? You’ll find out on ...