question about main bearings

im building an ej257 and was wondering whats the pros and cons on the position of the thrust bearing weather it be at #3 or #5?

i have a set of bearings and supposedly the thrust is suppose to fit #3 but it doesnt, its a bit too small and im wondering why because i ordered the standard size. ill have to call them up tomorrow and figure that out. they are ACL race bearings by the way.

how much better are the OE bearings compared to the ACLs?

one last question that is kind of off subject but are the sti block and legacy gt block identical?

thanks in advanced

 

The EJ257(STi) and EJ255(06+WRX,LGT,FXT,OBXT,BajaTurbo...) are very similar, but are not identical in every way. Some parts in the catalog list differently, hence they are not the same. I don't know the exact parts difference, but they are not totally the same.

 

what are the differences? do you know? i do know that in the parts list, there are part numbers that are different but you get the same part.

 

bump anyone?

 

Only Phase 1 motors (pre-1999) have the thrust bearing in the #3 position.


Next time I need bearings, I'm calling Calico. They supply Cobb among others. OEM bearing are an insane amount of money for what they are. My Clevites looked just fine after 20k.


Where did you get the bearings and what motor(s) did they say they were for?

 

i picked up acl rod and main bearings.

the block im building is the ej257

 

^ I got that part.


What I'm asking is what motor the seller said it was for. It could be a misprint on thrust position. Have you tried it at 5?

The biggest thing with getting into replacing bearings is making absolutely sure that your block and crank's oil passageway's are clear of any debris. Use several cans of carb cleaner and air to spray everything out, making sure there is nothing left in there. I've seen bearings chewed up from from metal bits that didn't get out from the hot tank.



Have you heard of plastigauge? You may want to check your oil clearances.

 

As far as I know, the only differences between the ej257 and ej255 are external; turbo, intercooler, and exhaust manifolds, and the intake manifold, but the difference there is it's not red like on the sti, otherwise it is the exact same piece just not painted. Everything internal like bearings/rods/pistons/cams/heads/etc are all identical between the two.

-Steve

 

i tried it at 5 also and it was also too small.

i have plastigauged what ive done so far.

 

What do you mean by too small? As in it doesn't slide onto the block? Or you don't have enough oil clearance?

 

it doesnt even slide onto the block.

 

You may have the wrong stuff then.