4.0 issues

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Shagoneer
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Re: 4.0 issues

Post by Shagoneer »

Someone snatched up the engine I wanted before I could get to it. Now I can't find one of a similar year. I've read some people saying that only a 97-98 donor engine will work, and others say that any 4.0 block will work.

Anyone know which is correct.
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tedlovesjeeps71
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Re: 4.0 issues

Post by tedlovesjeeps71 »

The only difference I know of is in the cylinder head. Around 99-2000, when they switched to the coil rail they added some bungs so it could be mounted.


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Cecil14
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Re: 4.0 issues

Post by Cecil14 »

The blocks changed a bit externally throughout the years, but only really to address NVH issues. They added some ribbing here and there, but nothing that would impact interchangeability. As Ted mentioned, the heads did change; in addition to the coil mounts, the exhaust ports changed several times. There's a list online somewhere detailing the different casting numbers and what changed. I'll see if I can't dig it up.

Edit: both the intake and exhaust ports changed at various times. http://www.enginebuildermag.com/2004/10 ... der-heads/


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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Re: 4.0 issues

Post by Shagoneer »

So I have the choice of a 2000 Cherokee engine, or a 1996 Cherokee engine, which would be better to get from the yard tomorrow.
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tedlovesjeeps71
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Re: 4.0 issues

Post by tedlovesjeeps71 »

96 since the 2000 will probably have the 0331 cylinder head which cracks.


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Re: 4.0 issues

Post by Shagoneer »

Image


Got a good amount done today.
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Re: 4.0 issues

Post by Shagoneer »

Also had a nice little dspo moment

Image


It's not a great picture, but that is a craftsman socket welded into the steering linkage as an extension.
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tedlovesjeeps71
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Re: 4.0 issues

Post by tedlovesjeeps71 »

Shagoneer wrote:Also had a nice little dspo moment

Image


It's not a great picture, but that is a craftsman socket welded into the steering linkage as an extension.
Image


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Re: 4.0 issues

Post by Shagoneer »

Also found out it has a Borla exhaust system. So the DSPO was willing to spend a ton of money on exhaust but wasn't willing to spend money to properly fix a steering linkage.
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Cecil14
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Re: 4.0 issues

Post by Cecil14 »

If you want to keep that exhaust (assuming header), make sure you match the generation of the new motor to the old one. As the heads changed a couple times, there are several different headers and they generally do not interchange.

It definitely sounds like swapping that motor out is the best plan for the moment. That PO clearly had no idea wtf they were doing. It should, however, make a great platform for a stroker build later. :)


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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Shagoneer
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Re: 4.0 issues

Post by Shagoneer »

Yeah, I was planning on keeping the current engine, and replacing all of the gaskets, rings, bearings etc, and doing the 258 crank while I was tearing into it.



On the subject of the 258 crank in the 242. There is a running cj5 with the 258 for a really good price. If I put the 258 crank in my 242, could I then put the 242 crank in the 258 and have the cj5 still run?
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Cecil14
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Re: 4.0 issues

Post by Cecil14 »

Probably? From what I remember, the 4.0L stroke is similar to the 232. You'd need to watch clearances on rods/pistons, but it should be doable. As to whether or not it's worth it...that'd be up to you. I kinda doubt it, though.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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Re: 4.0 issues

Post by Shagoneer »

Well my thought was that the guy is asking 1800 and his CJ5 has a full roll cage compared to my little factory roll bar, and the 258 I can steal the crank from.
So I buy it, cannibalize the parts I want from it, put it back together with the parts I don't want. Then sell it for what I paid.
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Cecil14
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Re: 4.0 issues

Post by Cecil14 »

Honestly you'd probably make out better parting it out, but it's a lot more work.


aa
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tedlovesjeeps71
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Re: 4.0 issues

Post by tedlovesjeeps71 »

Shagoneer wrote:Well my thought was that the guy is asking 1800 and his CJ5 has a full roll cage compared to my little factory roll bar, and the 258 I can steal the crank from.
So I buy it, cannibalize the parts I want from it, put it back together with the parts I don't want. Then sell it for what I paid.
By the time you buy gaskets/seals, replace worn bearings, make both run, etc... You'll have a ridiculous amount of time in each. I can't see how it'd be worth it.


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Re: 4.0 issues

Post by Shagoneer »

So then I may go with that idea of parting out the second one. Or give it to my wife's little brother and make him deal with it.
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tedlovesjeeps71
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Re: 4.0 issues

Post by tedlovesjeeps71 »

Would it not be easier to swap a 4.0 head on a 4.2?


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Cecil14
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Re: 4.0 issues

Post by Cecil14 »

Maybe? You have to make permanent changes to the head to do that. To build the stroker, you have to get into the bottom end, though if you're going to swap heads on an unknown motor, you should really do that anyway.

There are benefits to the stroker other than just the head, namely bringing the 258 up closer to "square."


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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tedlovesjeeps71
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Re: 4.0 issues

Post by tedlovesjeeps71 »

I agree Cecil, just thinking out loud. I don't like saying what "can/can't" be done... I just look at my own thoughts and financial fiascos and weight that against my OCD. I am one of those folks who will always have a buzzing in my ear if I shortcut something, waiting for it to break.
Best case here... Find a 258 crank cheap and build a fresh stroker. Go through it all and make sure all bearings and such are up to standard. Enjoy what ya build.
I don't think I'd be very confident in taking a used 258, breeding it with a haggard 4.0, and hope it all works. But that's just me.


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Cecil14
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Re: 4.0 issues

Post by Cecil14 »

Absolutely agree, that's why I poopoo'd just dropping the 4.0L head on the 258. I'm not a fan of band-aiding things.

Do it once, do it right.

aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank
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