Brian Douglas wrote: > I'm doing a top averhaul on my Revmastr 2100. I ordered new head and > pistons etc... My question, when I took the thing apart there were > shims under the rockers. What is the proper way to shim the rockers? > Are they there just so you can get the proper valve adjustment screw > engagement? or should I just put it togeather and see how the valves > adjust, then shim if I have a problem?
The shims are there to get the valve train geometry right. The "right" way to do it is to make custom pushrods the right length, but shims under the rocker stands will work within limits. The fact that they are there at all is a sign that somebody knew at least something about it when they assembled the engine. Although the Corvair is somewhat different, the principle is the same, and shown in excruciating detail on my Corvair valve train geometry page at http://home.hiwaay.net/~langford/corvair/valve_geometry.html . Proper valve train geometry is vital to long valve guide life. Improper geometry is responsible for a lot of (most) valve guide wear problems. The bottom line is that you want to shim the stand out so that the rocker tip is in the middle of its sweep across the end of the stem at half lift. So check it at full and no lift and the tip should be equidistant from the center of the stem (vertically). Mark Langford, Huntsville, AL N56ML at hiwaay.net see KR2S project N56ML at http://home.hiwaay.net/~langford
