Valve Shim Grinding

[Bruce Murray <bmurray@bbn.com>]

Hi Folks,

All this talk about grinding or otherwise reducing valve shim thickness,
suggests that some caution is needed.

If these shims are case hardened, as I believe they are,then removing their
surface(s) can remove their hardened face(s) and lead to premature wear.
Case hardening depth may be about 0.01 in 

That the shims should be hardened is obvious, otherwise the manufacturer
would not do it!

I would also be concerned about using emery belts etc to thin down shims
since you will almost certainly lose the parallel face and flatness which
can lead to valve train distress.

If it has to be done, use a surface grinder and check the face hardness
before use.

When I bought my e-type Jag I found no valve clearance in a few of the
valves and on investigation the DPO had fitted brass shims!!!!!

Cheerio

Bruce