Originally Posted by powertrip
Originally Posted by Brad_Haak
Tech info from Manton Pushrods, FWIW


Appreciate you furthering the discussion. It looks like with the shoe rocker they are trying to minimize "scrub", while with the roller rocker they want to minimize "sweep", both of which I agree with.

Where I differ with some is that you should measure from the center of the roller wheel, why?? All that tells you is the size of the roller wheel, which has no effect on geometry.

The tip of the valve stem is the point of contact, THAT is what matters.


The center of the roller is the reference point for the center of the arc that the wheel travels through. If you would plot pivot points for mid lift on paper, you would see visually that to achieve true mid lift geometry, the shaft centerline needs to be at a right angle to the roller centerline.


"use it 'till it breaks, replace as needed"