I need an opinion from those experienced in valve shim replacement: I have an "89 740 GL, B230 engine. I found a few clearances measured at 0.457mm and 0.483mm with 170,000 miles on the engine (3 of the eight are OK at around 0.406mm). I will be pulling the cam next week to replace hushers, distributor seals, etc. and wonder if you think its justified to "re-shim". My only concern is burning valves. Are these numbers close enough?

Also if you think it's justified what would you take it down to with a spec of 0.3 to 0.4. One shim step seems to be 0.05mm.

Thanks in advance.

Assuming cold engine it is out of spec but not enough to cause a problem, maybe just a bit more clickity lick but certainly not burned valves. If you are going to all the work of removing the head just to replace the cushers why not make the valves all within spec. It is so easy to do.

BTW no need to remove cam or even the head to install seals. Curious why the hed is coming off.
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David Hunter

Not removing the head, just the cam for the valve absorbers. Thanks for the advice.