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

For racers, the most pressing questions we ponder late at night aren't about the meaning of life, the true meaning of beauty, or other such silliness. Yes, those things have their place, but we all ...

An engine that just doesn't perform as it should at high speed on the dyno or racetrack can induce a series of checks that usually first includes measuring the pressure and volume of the fuel being ...

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 ...

Auto magazines are full of 1,000-horsepower LS engine stories teeming with superchargers, turbochargers, intercoolers, massive loads of nitrous, race gas, and all sorts of glamorous equipment. While ...

The rocker arm is possibly the third most abused part in your engine. The connecting rods take the cake for the most abuse, followed closely by the piston assembly, but we like to think the rocker ...