Valve lift and lateral forces on the valve guides

[Don Malling <dmallin@attglobal.net>]

List,

I understand that one of the advantages of roller rockers is that they
reduce or eliminate lateral forces on the valve guides at higher valve
lifts.

At what valve lift does this become important? For example, if I have a
cam with .425 valve lift using stock 1.45:1 rockers, do I have a
problem? How much valve lift can I have before I start needing roller
rockers. I understand this is not a binary thing -- If I have a little
too much lift I will have a little too much wear. Lots of lift, means
lots of wear. I have no feel for the range -- little problem to big
problem.

Thanks,

Don Malling