[Chrisyphus]

Another super thread res, Gasblip, I am just now seeing this response while trying to find a link for another post. To answer your question- yes. I think so, but I have no proof of that beyond the motors we have gotten in the shop over the last year or so since we picked up in the number of S65 orders we've gotten.

Every single motor that has been brought to us, save ONE motor with a torched piston, has had a spun #1 main bearing and oversized rod bearings. The brand does not matter IMO; whichever brand of bearing kit is the most popular is going to be the most prevalent in this sample group, so I will not name names. The fact is that of all the motors we have had in the shop with a spun main bearing, 100% of them have had oversized rod bearings, which all looked brand new despite having 20-40k miles across the board.

Of those cars, 90% have been well-maintained and cared-for street cars. One had 60k miles on the chassis and 20k miles on the rod bearings.

I have done significantly more research since the making of this post, and I am even more confident now in my finding that the issue is not the bearings; it is the lack of oil flow capacity in the OEM oil pump, which is exacerbated by increasing the engine's base oil flow demand by increasing the rod bearing clearances.