'Fast Road' specification to allow the engine to rev to 7.000 rmp and 0.415” to 0.440” cam lift. Supplied in sets of 12 inner and 12 outer springs
Manufactured from superquality silicone wire, their resistance against fading and breaking is extremely high. They can be fitted directly to the head with no fear of spring crush and enable the use of higher lift cams. Recommendable for fast road and race engines. Must be fitted when using competition valves.