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View Full Version : Rod and Main Bearings - Possible OEM at .010?


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happyhoppy
04-09-2008, 06:39 PM
Getting into my 2nd AMC 401 engine and everything looks great - bore standard with .002 at the worst but as I read the original AMC numbers on the rod and main bearings it turns out they are .010.

I know some engines are bored over at the factory but did the crankshafts ever leave the factory at .010?

Reason I ask is because the guy I purchased the Wagoneer from purchased it brand new and claimed it had never had any major work done - 54000 miles.

jeepsr4ever
04-09-2008, 07:16 PM
That is possible. AMC did have engine codes for oversize parts.

happyhoppy
04-09-2008, 08:21 PM
Thanks - it makes sense.
Thirty five years ago every crankshaft probaly didn't come out of the chute perfect.

tufcj
04-10-2008, 07:13 AM
Still have the original valve cover tag? There would be an additional letter at the end to indicate non-standard crank or cam bearings.

Bob
tufcj

happyhoppy
04-13-2008, 07:00 AM
Thanks for the replies - I'm slowly getting to the bottom os this.
The rod bearings:

AM
3193362
.010 US
Clevite 77
I took the crankshaft to the machine shop and everything measures better than standard +/-.0005 - no doubt whatsover it is standard. Can anybody tell me what the .010 would be?

My only guess in my limited knowledge would be that the actual rod and cap are larger ??? Valve cover tag is missing as it had Edelborock covers.

Shop did mention the rear main was slightly less with .0008 under but they said this was a good thing as it should have a little more clearance. Is this true with AMC motors - they can't ever remember doing an AMC 401. Not going to be a high rev engine.

fifesjeep
04-13-2008, 09:08 AM
Thirty five years ago every crankshaft probaly didn't come out of the chute perfect.
Hmmm, probably a lot closer than what most companies do now... lol

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