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 ...

Any gearhead worth his or her salt knows that whether it's a SOHC, DOHC, or OHV engine, the camshaft is considered the brain of a four-cycle internal combustion power plant. The camshaft's profile ...

The typical four-stroke engine is made up of hundreds of parts. These parts are all designed and engineered to work together to make a prescribed amount of power, torque, engine longevity, and other ...

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

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 ...

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 secret that adding duration and valve lift helps make power. But besides changing camshafts, there is another way to modify valve events-change the rocker-arm ratio. Ford V-8 rocker ratios-at ...

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 ...