Jerry,
Your logic leads to the same concerns that I have. In order to extract maximum potential from the racey S62 engine, you must flog it and run very close to redline and occasionally bump into the limiter.
This engine simply will NOT provide that level of performance over a normal street engine lifecycle which is now approaching 300K mi for most marques. IMO, the bearings are not up to the task at hand.
Your choice is to drive the car like a 540i after 100K mi (limit rev's to 6K) or get this racey motor rebuilt to maintain OEM capability into it's senior years. The cheap man's rebuild (in the case of S62 street car) appears to be...focus $ on weak points, namely, replace the rod bearings.
I will also say this....most cars with big V8's do not have racey 7K+ redline with such aggressive cams and tuning, so they do not see premature wearout or stress issues. Most mfrs put more cushion/buffer in their designs, so normal lifecycle is achieved under hard flogging. My Ford 5L had 300K mi with 40K+ merciless track miles and the motor was solid as a rock. It saw 1k+ RPM OVER redline on a regular basis without protest. It's power peak was 1000 RPM under OEM redline which made shifting optional in many cases. My Vette was on the rev limiter almost every lap and it did not care at all. They run forever in that mode, but that was the 90's. Mfrs are pushing the envelope now and BMW might have gone a little too far with E39, imo. I would not chip my E39 M5. When Z06 Vettes wit h7K RPM limit begin exceeding 100K mi in numbers, they may exhibit the same premature bearing wearout and engine failure issues. I don't know. The GM and Ford V8's that were limited by the factory to under 6700RPM are holding up for full lifecycle.
