Main bearing question
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Teching In
Joined: Apr 2009
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From: Toms River
Main bearing question I'm starting a 383 build on a used block that I acquired. The stoker kit that I bought is new(eagle crank). I was unable to get a proper squish on the plastigage when I went to set the crank. The stock sized main bearings fit the block seemingly fine. I then measured the block main journals at 2.760. So the main journals were apparently line honed prior to me. Do they sell a main bearing for an oversized block journal for a stock size crank journal? Thanks
Last edited by 302; Mar 27, 2016 at 09:02 PM.
How did u measure the main saddles in the block? If u have a bore gage then scrap the plastiguage and use the bore gage to measure the bearing clearance. Only use the plastiguage to double check your bore gage measurements.
If your block was line bored/honed then u can get a set of "X" bearings. They will have an "X" in the part # showing the .001 extra clearance.
Hopefully your block wasn't line bored more than .001 or more than one time.
My .02 is: if you don't have a bore gage you should bring your block to a reputable machine shop to have it checked out. Sounds to me you have some problems going on with the block and stuff. Those measurements need to be right on or u you will have major problems. Good luck.
If your block was line bored/honed then u can get a set of "X" bearings. They will have an "X" in the part # showing the .001 extra clearance.
Hopefully your block wasn't line bored more than .001 or more than one time.
My .02 is: if you don't have a bore gage you should bring your block to a reputable machine shop to have it checked out. Sounds to me you have some problems going on with the block and stuff. Those measurements need to be right on or u you will have major problems. Good luck.
Main bores should be 2.7509"-2.7514", and if it's aluminum block I would recommend staying on the low side of that tolerance. If you used a snap gauge or dial calipers, those aren't really precise enough to tell you the bore is within spec or not. A dial bore gauge really is the better way to measure, and since you're using Plastigauge, I'm assuming you didn't use one.
I agree with jayyk31, you might want to have it checked by a machinist before figuring out how to fix it.
I agree with jayyk31, you might want to have it checked by a machinist before figuring out how to fix it.
