Thread: ACL vs OEM Nissan bearings

So what's the deal? For OEM Nissan bearings you need to combine the numbers on the block and the crank, but the ACLs come in 1 size?

Also, are they really that much better than OEM Nissan bearings?

The ACL's are based on the middle grade of the bearing so your clearances come out right in the middle of things as far as oil clearances go. And yes they are a better bearing than oem. If you havent looked through the fsm the difference in bearing size between grade on the oem bearings is only like .00015-.0003. Nissans just did everything so exact its not even funny and thats why the motors last soo long.

ACL bearings are a harder bearing and meant for high hp or performance use. They can take a beating vs the stock bearings which are softer and tend to spin if there is any dry spot in the oil lubrication vs the ACL which isnt likely to spin unless there is a complete starvation at some point.

Been using ACL's for years and years and never had any issues. Oil clearances on the rods ususally comes out between .0015 and .002 every time.

Okay, then I'll see if I can find a set shortly

So, apparently, the bearings come in std, .025, .25 and 0.5. What should I do? Should I check what sizes I need (from the numbers on the block/crank) and take the set that's closest to the average size?

Or should I just take the standard set?

If you didn't have to cut the crank and just had it polished you will most likely be all set with a standard set for both.

If the crank hasnt been cut at all and is in good condition the Standard size bearings are the ones you need. Done deal.

I ran std for the rods and mains. My crank was stock but had been micro polished.

STD