[Enrique]

I had a Porsche mechanic listen to the car and he said the valves did not sound loud considering how wide I had the clearences set. He became interested in the mystery and through a shoestring trail of evidence, he managed to have a phone conversation with the man who ground my cam in 1981! (turns out this guy had reground quite a few 911 camshafts for this mechanic in the more than 10 years ago)

The mechanic also mentioned that valve clearences are there to counteract wear to the valve seats (mostly the exhaust). I had previously heard that valve clearence was there because valves expand as they heat up. Now if they expanded .005", how could they still move back and forth in the valve guides? What am I missing here?

Question: has anyone else checked their valve clearences HOT just to see how much they really expand? As I wrote before, I did it twice, and both times found less than .001" difference between hot and cold readings.

BTW, I do have new valve adjust screws in there. (from Pelican!)

Thanks all.