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

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

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

In the valvetrain of your typical pushrod engine, the rocker arm is a critical component that also is an excellent tuning device. To properly tune with rocker arms, though, you need to understand how ...

The rocker arm employs the use of a fulcrum or pivot to increase the cam lift by a given ratio. That increase in lift is the result of moving the pushrod pivot point closer to the fulcrum. That ...