Quote:
Originally Posted by Partee Racing LLC
.....
--Peter
PS: I should note that the No. 1 main bearing problem does seem to be relatively widespread. There are lots of theories, and I have mine, but there is really only one solution: more clearance on the No. 1 main bearing than the others. Most other BMW engines, such as the S62, show between .0005" and .001" additional clearance on the first main bearing not because of the chain, but because of the expansion of the crankshaft caused by the torquing of the harmonic balancer bolts. BMW specs maximum clearance of .002". On main number 1, I have gone as high as .003" and used .0025" on the remainder.
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Hmm, I guess this is a description issue (as I assume you know your stuff
), but I don't understand what you mean by "caused by the torquing of the harmonic balancer bolts", and I'm talking as a (UK) mechanic of many years.
By harmonic balancer do you actually mean the vibration damper as seen
here?
By torquing, that normally means the force required to tighten a bolt etc to the correct force (at least in the UK). Presumably it's not that because either they'd work lose (they don't as far as I've heard), or nothing would happen to the bolts, for if their was a tightening force applied to them by changes in engine speed, it wouldn't be enough to keep tightening the bolts.
So by torquing, do you mean twisting them along their length? (although again, I can't see how. Surely that could only happen if their was insufficient clamping force? In which case, surely they'd work lose?).
Anyway, I'm puzzled
, I look forwards to your explanation
.