In this installment of Greg’s great exposition of high-performance rocker arms, we’ll be looking at the science and geometry involved, which you really must understand before you start building an engine.

A pushrod selection consideration is the tuning effect of size, length, and stiffness of the components in the valve train. Any part has a natural resonant frequency at which it will vibrate and a point at which a small periodic input or disturbance coincides with the resonant frequency will cause the vibration to increase with each excitation input.

Friction is reduced using the roller lifters. Where the flat lifter is velocity-limited, the roller lifter is acceleration-limited.