Rocker arms are reversed engineered and a CAD model of the existing component is produced. The form of the existing component is normally designed for large volume manufacture where price is highly sensitive and can have an enormous influence on design. We take the existing design and improve it. Component mass is reduced, strength is increased and the rocker ratio can be altered. These are all legal modifications that meet FIA appendix K regulations for historic motorsport.
We have CNC machined rockers from billet steel as well as producing investment cast rockers. Examples include:
Le Mans Spitfire billet
Bristol investment cast