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.

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 ...

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 ...

An engine's power production is directly proportional to its air-processing capacity. Internal-combustion engines consume both fuel and air, but the air is far more difficult to ingest than the fuel.

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.