There are several broad rules of thumb that provide clues to whether increasing rocker-arm ratio will prove to be a performance boon with a given engine, cylinder head, and camshaft combination.

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 ...

Drag racers have been searching for tricks to gain horsepower since day one, and there are lots of ways to do it without spending a tremendous amount of time or money. One of the biggest downfalls of ...

On our test subject, a 2001 Camaro SS, these upgrades were realized during an engine build that was completed in 2007. At the time, the budget allowed for a set of PRC Stage 2.5 5.3L heads, while a ...