View Full Version : 401 rebuild
bignblue
08-17-2000, 08:30 PM
You may have seen my post about blowby in my '78 401. I called Summit Racing today about a rebuild kit, and while they stock rings they claim to not stock the camshaft and crank bearings. They have them for a '74 401, but not for the '78. My question is: is there any difference? Can I go with the '74 bearings without any problems? Instead of just re-ringing the motor I want to rebuild it completely, possibly with a roller cam, etc.
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'78 Chero WT
401/4bbl/TH400/QT
44s F&R
"Jeep: the toughest 4-letter word on wheels"
Drew M
08-18-2000, 12:45 AM
<BLOCKQUOTE>quote:</font><HR>Originally posted by bignblue:
You may have seen my post about blowby in my '78 401. I called Summit Racing today about a rebuild kit, and while they stock rings they claim to not stock the camshaft and crank bearings. They have them for a '74 401, but not for the '78. My question is: is there any difference? Can I go with the '74 bearings without any problems? Instead of just re-ringing the motor I want to rebuild it completely, possibly with a roller cam, etc.
<HR></BLOCKQUOTE>
The 1974 and 1978 cam bearings should be the same. I have new 1978 401 cam bearings for
$ 10.00. If interested, email me at: Maloneyam@hotmail.com
-Drew M.
BIGUGLY
08-20-2000, 12:58 PM
Good luck. Call Mose Davis at Odenville machine shop. Don't know the number call info. He can order your parts and do your machine work and probaly cost less. Contact me off list I can give more details. He is good with AMC's.
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79 Cherokee
BIGUGLY
360 Stroker/TH400/QT/44's
edelbrock performer pac
3"lift 33x12.5
bignblue
08-30-2000, 05:31 AM
Well, I THINK this is good news: I changed out the PCV valve (old one was installed by Stupid-Lube and I'm pretty sure they didn't use the correct part), cleaned out the air cleaner, yanked the filter from the oil filler cap and hit the road. Since then, I've had no oil in the air cleaner as far as I've been able to tell. Does this mean that I don't need to re-ring after all? I hadn't noticed any black or blue smoke from the tailpipe, and my oil level stays pretty constant, so what was up with that? Thanks all for the suggestions...btw, BigUgly--where in the h*ll is Odenville? How do I get there from Montgomery? Assuming of course that one day I'll need Mose's services. Thanks again!
P.S.--coolest thing in the world happened yesterday. I was leaving class to go to work, and noticed that some kind soul had stacked three Jeep hub covers ( the tall skinny kind that only cover the hubs) next to my driver's door. A little offering from the Jeep elves, perhaps? It's good to know that there's some good people out there. Plus, I now have a spare if anybody needs one.
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'78 Chero WT
401/4bbl/TH400/BWQT
44s F&R
"Jeep: the toughest 4-letter word on wheels"
Drew M
08-31-2000, 12:36 AM
[QUOTE]Originally posted by bignblue:
[B]Well, I THINK this is good news: I changed out the PCV valve (old one was installed by Stupid-Lube and I'm pretty sure they didn't use the correct part), cleaned out the air cleaner, yanked the filter from the oil filler cap and hit the road. Since then, I've had no oil in the air cleaner as far as I've been able to tell. Does this mean that I don't need to re-ring after all?
To test for bad rings you will need a compression tester. Test the compression in each cylinder and record it for future reference. Make sure the cylinder's pressure is w/in specs and not varying too much between cylinders or identical between two adjacent cylinders (possible blown head gasket between them). Next, squirt some oil in each cylinder and recheck the compression - the increased pressure reflects the ring wear as the oil makes up for the worn rings sealing ability.
From what you described, sounds like the rings are ok. Oil went into the air cleaner b/c the pcv was wrong and pressurized the engine causing oil to to go into the breather tube. The blue exhaust was the oil being burned w/ the gas/air mixture.
BTW: If you need rings in the future for a 1978 401, the TRW/Sealed Power part number is E302-[std,030]. I just got a moly set from PAW for under $70 for my 1978 401.
-Drew M.
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