OEM Bearing replacement

[Armond30]

I am not sure if anyone else has noticed, but buying OEM main bearings has become almost near impossible. I am still waiting on some bearings that I ordered "just in case" about 2 months ago. I have tried checking clearance on Aftermarket bearings (clevite, ACL) with new oem cranks, and I have come out with massive clearances which wouldn't stand a chance of surviving more than a few minutes. what is everybody else doing to compensate for this parts shortage? Is everyone buying oversized bearings and cutting their cranks to get standard clearance? Is there some source for OEM bearings that still has plenty of supply?

[sublime_whatigo]

It's always been quite the wait to get oem bearings. But I'm more concerned with your "massive" clearances with a new oem crank. Cleavite, King, ACL have always ran looser than stock, what are you clearances?

[Armond30]

the last time I checked brand new crank against fresh block with clevite and ACL bearings, I got (I believe it was) .003 (I as targeting .0010 if I remember correctly). It was enough to see daylight between the bearing and the crank with the girdle torqued fully. stock bearings on the same crank and block yielded the target .0010 or less depending on the color I used. it was a massive difference that wasn't worth potentially 6K of trial and error (new turbine wheels, turbo rebuild service, new rods, new rod bearings, new crank, new rod bolts, head cleaning, oil cooler cleaning, block cleaning, accumulator cleaning, new gaskets, new seals, time, etc. etc. etc). So I am just curious to what everyone else runs into.

[new93TT]

what about the ones thru ninja performance? they have listed on the site oem bearing sets

[sublime_whatigo]

I shoot for .0025, .001 is to tight. .003 is acceptable but I would run thicker oil. Your best bet if you can't get oem in time is to send out your ACL's for a coating, should put you right in the sweet spot.

Edit, oem bearings used to be color coated and came in several sizes. The new oem bearings may not be the best for your crank.

[RealMcCoy]

If you have a new or low mile crank that you know is sized correctly, your best bet is to line hone the block and resize the rods to get the desired clearances with aftermarket bearings. Then it's a very repeatable scenario if you ever need to replace them again.

I've seldom had more than .0025" clearance with ACL, King, and Clevite bearings... The vast majority of the time I see them right around .002"

[Jimvr4]

I got .0017-.0018 with Clevite bearings and a stock crank.

[donniekak]

I'm perfectly happy with .002"-.003" clearance. .001" is to tight. Most of the time kings, or acl's come out right around .002" on a good used crank.

If you want to get a little tighter have the main bores line honed to the tight end of spec. But if you plan on making any kind of power at all don't go tighter than .0018" ish.

Tight clearances and thin oil are for fuel economy. Loose clearances and think oil are for horsepower machines.

[Armond30]

Thanks for the advice guys. I think I see how everyone deals with this issue now.