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Unread 03-29-2010, 06:26 AM   #1
Oily
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Parts Interchange Between 4.0 And 4.2 ???

I can get a running 4.0 for free. It is out of an 86 Cherokee and has some type of fuel injection. I don't think it is the High Output 4.0 though.
I just want to use the engine for a short while during the rebuild of my 4.2. Basically just use the block/head assembly. Just wondering if my stock intake and exhaust manifolds will bolt up. Also my power steering and alternator.
I will have to pull it from the Cherokee in less than ideal circumstances and don't want to mess with it unless I can use it.
Thanks in advance, .

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Unread 03-29-2010, 06:37 AM   #2
Mike Romain
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Yes it should work. You need to use the 4.0 exhaust manifold though and can trim the 258 intake to fit. I am currently swapping a 93 over as well these folks are doing one too.

http://www.jeepforum.com/forum/f8/he...ad-cj-1000370/

http://www.jeepforum.com/forum/f8/4-...nifold-997989/
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Unread 03-29-2010, 06:41 AM   #3
gmakra
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Oily the intake will work with a bit of work, you will need to center you intake over the 4.0 intake ports since they are larger. The exhaust manifold probably will not work a least I have never heard of one working. So you will probably need to get a 4.0 header You will need to use large washers to make up the distance between the two manifolds when you bolt them on.

Your accessories will bolt on though you may have to make something work on the power steering pump. The two things that will give you grief are the top aluminum bracket that is secured by a head bolt and the bolt that goes through the power steering bracket into the intake manifold it probably wont line up.

Use your old flywheel and starter on the 4.0.

Keep the harmonic balancer from the 4.0.

And you will need an electric fuel pump.
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Unread 03-29-2010, 06:47 AM   #4
Mike Romain
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Quote:
Originally Posted by gmakra View Post

Keep the harmonic balancer from the 4.0.
I just knew this was going to be too damn easy....

OK, I cannot use the 4.0 harmonic balancer because it has a serpentine pulley on it and I need a V belt pulley balancer. My 258 balancer appears to have the pulley as part of it though I haven't pulled it off yet.

Is that going to be an issue?

here are some good photos of the intake and exhaust job: 4.0 head swap - Vincent - Picasa Web Albums
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86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
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Unread 03-29-2010, 11:09 AM   #5
1986cj
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How does the 4.0 run? I would swap the whole thing in if it runs good. It is not a HO (91-95 OBD1) it will be a renix fuel inj system (87-90) but will have more power that your 258. The renix system is not bad just not that easy to get parts for. I have a great article of a swap of one into a 86 CJ7 if you are interested and want to read it, let me know and I will send you the link.
You got me thinking I am not sure but you may have to use the 258 distributor too. The 4.0 distributor will have the cam sensor in the dist and not real sure if it will work right without the ecm. The 258 one will fit right in the 4.0 but you may want to research if the 4.0 one will work with out the ecm.

Last edited by 1986cj; 03-29-2010 at 11:29 AM..
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Unread 03-29-2010, 07:15 PM   #6
gmakra
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It shouldnt be but the 4.2 crank is slightly longer so you balancer may pull up a little to much on the crank. But give it a try it should work.
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Unread 03-29-2010, 07:46 PM   #7
gojeepin
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You probably won't be able to use your CJ intake manifold with this head.

The RENIX intake ports are larger than the CJ intake manifold can cover/seal. They are larger than the 4.0L HO head because the RENIX fuel injector was mounted at the mating surface between the manifold and head, unlike the HO head.
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Unread 03-29-2010, 10:20 PM   #8
Oily
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Gosh. Thanks guys.
I was hoping I could just bust a few knuckles. Should have known better than to ask. Now I have to think.

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