Roller Rockers on Stocker Engine ?

[Bill Edgeworth]

Originally Posted by randy wilson

pushrod length does not change valve lift or duration. only cam profile, rocker ratio, and valve lash can do that.

Randy,
You are incorrect. It especially affects punched steel (non roller tip) rockers. When you use a long pushrod it brings the short side of the fulcrum closer to center effectively increasing rocker ratio. It affects roller tip rockers less because the tip radius is much smaller compared to the pad on a punched steel rocker.

[Alan Roehrich]

Originally Posted by randy wilson

pushrod length does not change valve lift or duration. only cam profile, rocker ratio, and valve lash can do that.

Pushrod length directly effects valvetrain geometry, thereby directly effecting rocker ratio, and from there it effects lift, and duration.