MADE in many different shapes and sizes, rocker arms transfer upward movement from the pushrods into downward action at the valves, and then return to their original position. Simple.
But things get a bit more complicated than that, since rocker arms come in different leverage ratios, from the VW Beetle’s 1:1 (where half an inch lift from the pushrod is matched by that same amount of downward movement at the valve), to many other engines that use
