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post #1 of (permalink) Old 06-18-2003, 08:58 PM
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4.2 rebuild

I'm getting ready to start the rebuild of my 258. Block nearly stripped to go to the machine shop.Any suggestions for Jeep engine [img]images/graemlins/givemebeer.gif[/img] [img]images/graemlins/givemebeer.gif[/img]parts suppliers w/ good quality and good prices.I'll also be doing the 4.0 head conversion at the same time. Are there any cam upgrades that I should consider.I'll be running the Motocraft carb until I can afford FI.This is a daily driver w/ occasional beach use (can't give up surf fishing). Of course I could forgo the rebuild if someone out there has a rebuilt 4.2 avail in the vicinity.
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post #2 of (permalink) Old 06-18-2003, 10:15 PM
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Re: 4.2 rebuild

PAW for the parts, if you don't mind waiting a coupld of months i'll have a nice 258 out of my 78 with under 70k that runs like a champ, but you're probably better going with the rebuild [img]images/graemlins/grin.gif[/img]

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post #3 of (permalink) Old 06-18-2003, 10:59 PM
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Re: 4.2 rebuild

1. Ray, welcome to the forum.
2. Thanks for filling out your user profile.
3. Read the New Posters Message at the top of the forum.
4. Participate more often!
5. Two brains are always better'n one!
6. Check out the 1997 Issue's of JP Magazine [*] Feb - March [*] April - May[*] June - July[*] August - Sept
6. There's a Four part series on re-building a 4.2L engine,
7. It is a very good series on what needs to be done.
8. I have it scanned, but it's 12 megs of data...
9. If you need it Emailed... we can work something out,
10. PM me or send me an Email.
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post #4 of (permalink) Old 06-19-2003, 10:50 AM
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Re: 4.2 rebuild

I might be interested in the used engine. What can you tell me about it.
Actually the block that I'm working on was purchased used and was supposed to have beed rebuilt with less than 20k mi. When I pulled the pan to inspect bearings prior to install they were found to be shot. Having seen that I'm now thinking about a total rebuild.
What about the cam......out there. Should I upgrade and with what? I anticipate replacing cam and cam bearings anyway.
post #5 of (permalink) Old 06-19-2003, 10:58 AM
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Re: 4.2 rebuild

1. Remember one thing...
2. There's usually a limit of two rebuilds to a block,
3. It's limited by the amount of Cylinder boring.
4. The block's at .030" over now,
5. .060" is the max.
6. Anyone sleeve cylinders to get a little more out of it?
7. As for the cam, keep it to OEM specs...
8. It's almost a perfect cam unless you do some wild engine re-engineering.
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post #6 of (permalink) Old 06-19-2003, 01:47 PM
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Re: 4.2 rebuild

if you get it bored, have them plain the deck too in order to try to keep the compression up. i didn't do that with mine and now the compression is only at 130#

just my .02


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post #7 of (permalink) Old 06-19-2003, 02:11 PM
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Re: 4.2 rebuild

The engine is the original 258 in my 78, the manifolds have been replaced with those from an 83 for some reason that i could not even try to guess at. it has the pos carter on it that i have rebuilt. the engine starts right away and runs like a champ. it had 63k on it when i bought it and by the time (hopefully within the next two months) i get my 360 done and ready to go in it will probably have under 70k. the engine is pretty much bone stock, except it has the ford cap/rotor and is hooked up to an msd (which stays with the jeep for the 360). if you are still looking when i get ready to pull it i will let you know. everything comes with the engine except the alternator and the msd box (engine, head, manifolds, carb, smog pump, distributor, flywheel)

as far as your engine goes if the bearings are bad you may want to tear it down and see what else needs to be done. if the cylinders still look ok then you shouldn't have to bore it which will save you a bit of $$. PAW has kits for the 258 that include everything (all gaskets/seals, rings, bearings, timing chain, oil pump) for under $200 i believe.

good luck

-web
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post #8 of (permalink) Old 06-20-2003, 07:05 AM
 
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Re: 4.2 rebuild

I double that thought about the cam. I got a mild cam in mine during rebuild and it has caused me nothing but headaches. It simply makes it more difficult to get it tuned in properly and running smooth and for no good reason. Also it costs more and often requires head work. The stock cam is just right for the 4.2. I wish I could go back and change my mind.

Oh well.
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