Billet cams and lifter supply

[Stan Weiss]

Originally Posted by Rory McNeil

Totally different situation. The OHC engines with buckets have no rocker arms, lifters or pushrods, so the valve springs are generally much less tension, since the weight of the valve train is so much lighter. Even more so with a 4 valve head, since the valves are considerably smaller, as are the spring diameters and retainers. Also, the buckets do not need to rotate like a flat tappet cam, and the cam lobes are not ground on a taper, to promote rotation.

Let leave 4v DOHC out of this and just look at 2v Single OHC. While there is no rocker arm or pushrod the bucket replaces the lifter and is traveling at valve velocity / acceleration while the lifter would be traveling slower.


Stan