Quote:
Originally Posted by dvsd1991
pictures uploaded of bearings 2 and 3
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Very different wear rates between these two. Assuming there's no plugging up of the hole passage for #2 it could also be too tight of bearing clearance on #2 or wrong bearing set chosen. The wear pattern on #3 looks exactly like E90 BWM bearing failures which was caused by wrong tolerances. But who knows if oil starvation bear failure ever looks different from low clearance failures....
The big ends passages are cross drilled so you can look down them to see if they have blockage and that the diagonal drill was capped properly or force some water into your oil galleries to see if equal amounts comes out of 2 and 3.
Looking at the 2022 BRZ FA24 parts, #2 and #3 still share the same center main bearing oil passage so if they didn't "fix" this, I would trust Subaru in that sharing an oil passage from the center main bearing may not actually be an issue.
The more I think about this the more it seems like a statistical tolerance stack issue across manufacturing. The bearing sets on FA20 are used for forester,brz,wrx,legacy,outback,xtrek basically across the entire product line and it goes from STD, 0.03,0.05 and then big jump to 0.25.
All 4 are shared parts. Now if we look at 2022 BRZ there are now
5 bearings sets, 1 size is shared across all the FA24s and the remaining 4 sets are 2022 BRZ specific and not shared. This could be real reason FA24D will be more reliable + the fatter straighter rods