Engine Rebuild Part 2 - Valve Train KB

I am just going to list the most critical links that should be read in order of importance.

1. Raby's Ultimate Valve Train Geometry Article

2. 911 adjuster mod into 1.7 rockers

3. More on 911 Adjuster mod - grinding the rocker

4. Forums containing problems you may run into

http://forums.aircooledtechnology.com/showthread.php?5521-Valve-train-geometry-911-adjuster-clearance-needed

http://forums.aircooledtechnology.com/showthread.php?1448-Rocker-geometry-w-lousy-pics

http://forums.aircooledtechnology.com/showthread.php?2089-trimming-911-swivels


Summary:

The main concern is maintaining the correct geometry of the rocker assembly. To maintain the correct geometry, with custom valve train, the push rod must be adjusted and shims possibly added to the rocker mounting. Also the 1.7 style rockers must be shaved on the face (side opposite the lock nut) to provide clearance for the 911 style adjusters.

From my research so far the following is a good starting point.

1. Shave .06 thousands off the face of rocker. Use the techniques in 2. and 3. above as guides.
2. Use 1.  above as a guide to adjust the rocker assembly and push rods to give the correct valve train geometry

Note: there is a possibility that you will need to add shims, and shave more off the rockers and to cut the rods. It is not a exact process since every engine is different.