RHS head valve train geometry issue

Rat Patrol said
As you can see from the 2nd pic...shimming the pedestals will push the rocker tip further off the valve - so shims may only be a 'fix' for Hughes rockers.

Rat, I'm glad you are giving this serious thought. In your pics, the roller is pretty close to centered when the valve is on the seat, but rolls way over to the exhaust side during the lift cycle. Anyone can see that is no good. Shimming up the stands will move it further to the exhaust side, but up is the right direction. The Trig angle between the valve stem and the rocker stand requires that the shaft be offset when it is raised. Add in the fact that almost every rocker available is way too long, and it compounds the problem, requiring even more offset.

By the way, shims aren't a fix for anything. Usually, over time, the stands will crack from forcing a flat piece of metal between the shaft and the stand. Also no good. A spacer that raises AND offsets the shaft is a viable way to correct the problem, or have the stands milled off and new ones made. A word of caution though. The person milling off the stands and making new ones had better know what he is doing, or it will still have terrible geometry, whether the roller is centered or not.

Here are a couple pics to show what it should look like on the seat and at full lift. The total sweep across the valve tip was less than .030".