Help With Bearings

[Nesquick]

k so im building my bottom end since i fried 3 pistons

so im doin a rebuild the PROPER way so that nothing will be blowing again anytime soon.

iv already got my pistons picked out (Custom Weisco 9:1 with 20 over)and Eagle Rods (still undecided about which ones)

but im clearly undecided on bearings.....iv heard alot of good things about ACL and Cosworth.....but i have NO IDEA on if i have to get a special order because of my over bore or if the regular sizes would still work.

On a side note, anyone know what would be better for my setup (R33 RB26DET w/ gt40r), the " ACL Race Series Pros" or "ACL Race Series" or "ACL Duraglide" or if any of the cosworth series would fit my needs perfectly.

thanks for the help

[Darius]

I haven't heard anything on Cosworth bearings only because I don't think they had bearings when I was rebuilding. Their head gaskets are great, so I'd assume that their bearings are top notch as well.

I used ACL race bearings for my RB25 since they were readily available. Bearings shouldn't matter if you have a good oiling system. Which reminds me, have you checked the crank snout to verify that it has the long drive on it?

Bearings don't have any relationship to overboring the cylinders, so don't worry about that. You have that covered with the new pistons. What you should do to be "proper" is micrometer the crank journals and the inside diameter of the new rods. Then by simple math, you can figure out what bearing thickness is required to maintain the factory oil film thickness between the crank journal and bearing surface. This will take two separate micrometers (measuring to 0.000 mm) at a total price of about $500. Or you can half-a$$ it and order standard-sized bearings, torque it together with plasti-gauge on the journals and see if the clearance is within spec. Plasti-gauge is $0.15/ft and will probably do the trick. The advantage to using micrometers is that you can tell if any of the journals are tapered front to back or out of round.

Good luck!! Sounds like a mean build

[Bluefire]

I use ACL race bearing all the time and have zero issues with them. And as long as your crank and journals don't have any major bearing wear on them, you should be fine running standard sized bearing.

IMO the bore gauge and micrometer method is only really needed if your looking to build a competition motor where a couple hp actually means something. In reality, plastigauge fine for checking tolerances. Something else in the motor will go before the bearing do...