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 ...

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 ...