Description
Rocker arms are a crucial part of an engine’s valve train, transferring camshaft motion into the valves. The camshaft lifts a lifter, which moves a pushrod, and then the rocker arm pivots to activate the valve. By adjusting the pivot point of the rocker arm, its ratio changes, affecting how much the valve opens. For instance, a 1.5:1 rocker arm ratio means the valve opens 1.5 times the cam’s lift. Performance builders often use different ratios to enhance engine performance. Rocker arms can be mounted on shafts or studs and are made from materials like stamped steel, cast iron, or lightweight aluminum for high-performance engines. Many feature bearings and roller tips to reduce friction and improve durability at high RPMs. While simple in appearance, rocker arms play a vital role in the proper function of the valve train.