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4.0 Rebuild kits? Which is best?

S

Stroketech

NAXJA Forum User
Location
Mankato MN
Hi everyone, i'm going to rebuild a 4.0 to put in my '00 Cherokee. I've rebuilt several small block Chevy's but i've never done a Jeep motor. What do you guys reccomend for rebuild kits. I've heard some guys talk about coated pistons to help cut down on piston slap? Any ideas on that? Any info would be great!


Jon
 
I found that unless my rebuild required zero machine work.. I could buy a reman cheaper. I know this place isn't local to you but it can give you an idea of what they can be had for.
Short block= $400
Short block assembly (short block but has oil pump etc) = $540
Long block = $770

http://www.blainesmotorsupply.com/prices.htm

About the coated pistons, the skirts might not wear as fast so the engine might go more miles before having piston slap, but the key to having little or no piston slap is close tolerances, which comes down to how closely the bore is matched to the pistons.
 
Thanks, I might get ahold of them. Thats crazy cheap from what i've seen. However I dont see the jeep motors on the price list unless i'm just blind. Thanks for posting the prices and the link.
 
Being in MN.. I'm not sure how you can use them.. by the time you shipped your "core" there.. or paid the "core" charge.. and had them ship you a engine.. wouldn't be quite as cheap..
If your not able to find prices this good near you.. maybe you need to look for a j-yard engine with good compression and oil pressure..
I did a "poor boy" rebuild on my motor. I took it apart and replaced only what showed excessive wear. Which was the crank, rod bearings, crank bearings, oil pump, lifters, timing set, and head. It only burns about 1/2 qt between oil changes, even at 270k miles, so I left the pistons and rings alone.. the cam showed normal wear..
I "rebuilt" it for probably about $400. My biggest cost were the reman crank and the head. I took a gamble on the cam bearings.. but my oil pressure is excellent so they must be fine.
 
If your block doesn't require boring..and you could get away with only having to pay to have your cam bearings installed, you could do the rebuild yourself for pretty cheap. Just check your deck and head for warpage... get a valve job.. I bought a reman head for $190 which was cheaper than I could have fixed my head for..
 
Thats why I planned rebuilding this myself. I've rebuilt many engines just never a Jeep 4.0. Thats why I was inquiring on what brands seemed to work best with the 4.0. Some brands work good together. I was planning on getting a reinforced cyl head for it. I'm going to send the block out with whatever pistons I have to get them matched so I can cut down on the chance of piston slap.
 
I have personally never rebuilt an engine or even pulled one out. My XJ is a 1999 4.0 and has been sitting for over 2 years. The engine originally overheated and I could not get out of traffic to pull over in time and it really overheated and had time to mess things up. How bad, I have no idea.



When it did start, it would run for a short amount of times then it sounded like small metal balls hitting the hood (best description I have) .



Anyway, I want to do it myself. There are way too many resources out there to look at. I trust this forum as the group is knowledgeable. Any places I can look for pulling the engine and rebuilding it that are good instructions and video for a first timer? My other option is a guy that will pull the engine and rebuild it for 3K. The link to his biz and info is here, he seems ok but it is a high price to pay and then something else could go wrong since it has been sitting. I love the jeep. If I can find the audio / video of the noise it was making will post. Anyway, can't wait to hear back from you guys.



https://www.google.com/search?clien...ilders+6815+W.+Belmont+Ave+Glendale,+AZ+85303
 
OP, your profile says east coast so I'm curious why you pick a rebuilder in Phoenix?
 
JeepLovinMonkey said:
I have personally never rebuilt an engine or even pulled one out. My XJ is a 1999 4.0 and has been sitting for over 2 years. The engine originally overheated and I could not get out of traffic to pull over in time and it really overheated and had time to mess things up. How bad, I have no idea.



When it did start, it would run for a short amount of times then it sounded like small metal balls hitting the hood (best description I have) .



Anyway, I want to do it myself. There are way too many resources out there to look at. I trust this forum as the group is knowledgeable. Any places I can look for pulling the engine and rebuilding it that are good instructions and video for a first timer? My other option is a guy that will pull the engine and rebuild it for 3K. The link to his biz and info is here, he seems ok but it is a high price to pay and then something else could go wrong since it has been sitting. I love the jeep. If I can find the audio / video of the noise it was making will post. Anyway, can't wait to hear back from you guys.



https://www.google.com/search?clien...ilders+6815+W.+Belmont+Ave+Glendale,+AZ+85303
Click to expand...

You can buy a reman for less than $3k so I'd personally go that route instead of having that local rebuild. Unless you don't feel comfortable swapping in the reman yourself, of course.

I've rebuilt 2 4.0s this year (88 & 00) and they were about $800 each. If you need to buy tools then it'll be a bit more. This also doesn't include anything outside of the motor that you'll say "well if I'm doing this then I might as well do that"... like lines, hoses, exhaust header, and the big one... Labor.

While I've thoroughly enjoyed learning the ins-and-outs of these motors, I will gladly pay for a reman next time. The additional cost is well worth having my nights & weekends back.
 
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