[regular guy]

Originally Posted by bigjae1976

Is the expectation for the engine to last 200k miles?

IMO, technology from 30 years ago: no; technology from today: yes. I think 200k miles on today's technology with an engine that is properly clearanced and properly maintained is what one should expect.

Originally Posted by Top_Gear

(3) Last year when the car came out of warranty I started making plans to add a little more power to the motor. Two options: the 4.6L stroker or one of the better centrifugal SC kits.

I'm not telling anybody to go out and rebuild their motor. But if you are rebuilding, then you definitely want to have it sized correctly at that time. And while rebuilding, if you're thinking of doing a stroker, then that's a great time to do it. I think the stroker would run about $7500 more than the cost of a straight rebuild. I would also agree with Kawasaki and BMRLVR and run thinner oil, and I would do it whether I was in or out of warranty.

As for getting together, I certainly appreciate the offer if you happen to be in the SF valley and we can setup a meeting but I am not sure we can't figure this out via PM. I have already seen the high resolution rod bearing pics posted by EAS and some of the others on this forum but I am not sure how this helps me with my long term plans for this car.

I'll probably be going through the Valley back from OC Friday evening around dinner time. PM if interested.

Originally Posted by Yellow Snow

But in reality are there any real risks in running with original bearings and clearances? I change oil every year at 5k miles, so it's pretty clean.

Yes I believe there is such risk. We've seen many sets of damaged bearings from people who drive just like yourself and change oil every 5k miles.

The BMW M engineers know how to build engines and something like getting the clearances wrong is remote after the S54 problems.

It's not uncommon to have two sets of staff work on alternating generations of HW designs. HW design fixes often times skip a generation because the HW design for the next generation is already set in stone when the discovery is already found. I don't think it's too far fetched to rewind the clock and see how the S65 was already designed and being tested when the S54 issue was finally acknowledged. I'm not saying this is what happened because I don't really know; but I am saying I could understand if this was the case because I see this same thing in my own industry.

If by chance it should happen and a bearing spins with damage to the journal. The crank can then be ground for the thicker, -.25mm bearings. Why pay now when you can pay later? (if it happens)

I don't think it's safe to assume all spun bearings will be fixed by a regrind crank and oversized bearings. Here's a photo of a S65 connecting rod on bone stock car. It's my understanding the driver changed his oil often. Then one day he went around a turn at Laguna Seca, spun out and stalled the car. When he restarted the car, it went into limp mode. They towed it straight to the dealer, and this is what they found.

Notice the blue color on the big end of the connecting rod. Blue == excessive heat == lack of lubrication. No reground crank for this motor, it was a total loss.