Thanks for all the responses. I guess it's hard to communicate what you hear
sometimes. All I know is that this machine should be quieter than it is. The
sound I'm hearing sounds like a heat shield rattling at certain RPMS. I'm
pretty confident that it is not a timing issue. The rattle commences exactly at
2800 rpms and continues through about 3000 rpms. At 2700 no rattle, a touch of
the gas....rattle! The frequency, volume, intensity is consistant regardless
of stress on the engine ie driving on a flat road, except, I can't duplicate it
sitting still with the hood up! It sure sounds like valve gear to me. I'm not
very confident in my measurement for push rod length. The stock seemed
slightly long, the PI rods (BPNW) seemed way too short. I didn't measure the
difference in length, but it is at least 1/2". I had a mechanic confirm the
geometry was OK. I milled the head for a combustion volume of 43cc. I didn't
measure the depth of the head. If something serious is wrong, I must be lucky,
because I've put about 250 miles on the car since I put the head on. Joe Davis
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