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STOCK
29-11-2006, 08:20 PM
Hello to the engine builders out there!

Im about to start my main conrod bearing slection for my turbo B18C2 motor and am not sure what clearance to select. I have a honda workshop manual which suggests a clearance range of 0.0013"- 0.0020". I was planning on selecting bearings for the largest clearance as i dont want issues with not enough oil coating the bearings under high load high rpm operation. Is there any negatives to this selection?
ProECU
29-11-2006, 10:41 PM
yes... spun bearings.
Muzz
29-11-2006, 11:08 PM
yes... spun bearings.

maby u could recomend what clearances he should be looking for, be a little more helpful:thumbsup: .
Slow96GSR
30-11-2006, 08:49 AM
Those specs are what I use in all my cars. .0020" won't cause a spun bearing, just let a little more oil through. I would get one .0015"ish. Then you have to select the manufacture, ACL is what we use then get them from Calico Coatings. The FULL bearing kit is $200USD for the mains, rods, and thrust. Well worth it for a race motor.
ProECU
30-11-2006, 09:50 AM
it's good practice to shoot for the larger clearances in the middle of the crank, and the tighter ones on the outer ends.

I was messing around with the spun bearing comment, but there is an element of truth to it. More oil on the contact surface is what causes spun bearings.
spardikis
10-12-2006, 01:08 PM
slow gsr - how can you order a bearing kit when you need to test and find the right clearances in the specific bearing? Ive just never really figured this one out.
What comes in the bearing kit? or do you somehow use a micrometer and order the specific bearings to suit in the kit? or does it come with a selection of bearings you test with plastiguage strips until you have the desired bearing selection to suit clearances.

if you could make this a bit clearer for me id apreciate it.
Slow96GSR
10-12-2006, 06:09 PM
It's easy... mic the bearing surfaces on the crank, rods, and mains. You already know stock specs, it's in the manuals. Once you know the sizes you call in the order. You'll need to make sure to tell them if the crank is a stock/smaller diameter, and by how much, and if the mains/rods are a stock/bigger diameter and by how much. Not too many rotating assembly kits make the crank bigger and the rods smaller than stock, nothing would fit! Get the numbers and I'll call in for part numbers. The kits aren't actually put together until you order it.