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

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 ...

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 next generation of pushrod engines.

The debate over the optimum rocker arm ratio has dragged on since the invention of the pushrod V-8. Even though Chevrolet made the decision easy for us when it engineered the small-block to run around ...

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 ...

Pushrods convert the vertical motion of the lifter from the camshaft lobe into valve movement. A V8 engine takes advantage of that by centrally locating a single camshaft in the middle of the engine ...