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

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 ...

If you are into precision engine building, you've no doubt heard the standard line for establishing the proper pushrod length: With proper pushrod length, the rocker tip should be in the center of the ...

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