Engine rattle, spun bearing? Now wont start

[Ultramaroon]

Originally Posted by demasrv

Oh my god those alignment pins would've been so useful.

Right?

[Capt Spaulding]

Those pins are genius. And would seem to be dirt simple to make. Big to NHM.

[chipmunk]

OP, have you considered buying a low mileage salvage and do a full engine swap? In my area, it's around $4000. There are plenty of crashed FRs and BRZs out there, just make sure that it's a side impact or rear end. I wouldn't touch frontal collisions.

[dvsd1991]

Got the engine apart today, #2 bearing went out

[FrickingReallySlow]

Originally Posted by dvsd1991

Got the engine apart today, #2 bearing went out

Thanks! 2 and 3 share the same oil passage, any pics you can share with us the rod bearings of 2 and 3? would be interesting to see the amount of wear on 3 even though it hasn't spun.

[dvsd1991]

Originally Posted by FrickingReallySlow

Thanks! 2 and 3 share the same oil passage, any pics you can share with us the rod bearings of 2 and 3? would be interesting to see the amount of wear on 3 even though it hasn't spun.

I will share when I split the case, I haven't gotten that far yet

[dvsd1991]

pictures uploaded of bearings 2 and 3

[FrickingReallySlow]

Originally Posted by dvsd1991

pictures uploaded of bearings 2 and 3

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