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 ...

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 ...

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 ...