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5.2L Magnum XJ engine swap

Bloose

NAXJA Member
NAXJA Member
Location
WI
Hello everyone,

The 4.0L in my '98 appears to have seen better days. The other day while I was on the freeway the drive on the oil pump broke and I lost oil pressure. I was pissed so I drove the POS to the off ramp and to the nearest gas station. When I finally shut it down it was making quite a bit of noise. At this point it's time to consider which motor is going to replace the original.

My main question is, has anyone either done or considered doing a 5.2L (318 Magnum) swap into the Cherokee. It seems like such a natural fit as they came in the Grands. Putting a Chryco motor in my Jeep would really help out in the emissions department as I still need to do that here in WI. They no longer do tail pipe testing and only plug into the OBD2 port. So running a Chryco computer from some '98 would keep me from having to jump through hoops. Also, keeping the 241OR t-case that I paid a kings ransom for is high on my list and running a Jeep trans would make keeping it a reality.

Is a 5.2L swap as attractive as it appears to me? I really don't want to get into a discussion about the $$ to HP reward of such a swap because increasing the HP of any V8 is a much simpler proposition than on any I6. V8's from any of the big 3 enjoy immense aftermarket support where the 4.0L enjoys some but not to the extent of the V8's and not at the low prices. I'm more concerned about if there is a real reason no one does these swaps, i.e. the motors won't fit, the trans is too big, or some other situation I'm not seeing.

If I could do any swap I wanted I'd run a 5.0L Ford V8 in there. They are small, light, and nearly as cheap to build as a SBC. The make tremendous power for their physical size and are extremely reliable. Not to mention that I have several 5.0L's laying around, one of which is freshly rebuilt. I also have a good AOD I could use. The AOD is nice because it has O.D. yet doesn't require a computer. The problem is, no one make an adapter to mate a Jeep T-case to the AOD. Also, emissions would be a problem as it is not a Chryco product. The FI I have for the 5.0L is from a '90 further complicating the emissions situation.

I know lots of guys have done the LS swaps but I'm not too interested in that because of the price of admission. If I had or could get a complete LS for cheap I'd consider it but there are far more costs involved with the LS swaps.

My last resort would be a Golen 4.6L stroker. I'd like to go to a V8 if possible so I'd like to steer clear of the stroker but it would be the simplest option.

Thanks for any input,
B-loose
 
Interesting proposal - based on what I'm finding, the 318 Magnum (5.2) has a 23-spline output. This should allow you to retain the 241OR provided it bolts up to the Magnum's transmission.

http://www.backwoodsoffroad.com/cgi-bin/imcart/read.cgi?article_id=2&sub=2

That article details the process for the TJ but should give you an idea of what to expect in terms of parts and labor.

Now, the brunt of your question (will it even fit in the engine bay?) I cannot answer, but would be interested to learn as well.
 
Interesting proposal - based on what I'm finding, the 318 Magnum (5.2) has a 23-spline output. This should allow you to retain the 241OR provided it bolts up to the Magnum's transmission.

http://www.backwoodsoffroad.com/cgi-bin/imcart/read.cgi?article_id=2&sub=2

That article details the process for the TJ but should give you an idea of what to expect in terms of parts and labor.

Now, the brunt of your question (will it even fit in the engine bay?) I cannot answer, but would be interested to learn as well.



Thanks for the link! It looks as though the swap is just about what I was thinking it would be. The XJ's engine bay is tighter than the TJ's but V8's fit into the XJ pretty well and the 318 shouldn't be dimentionally different than most others.

B
 
the 5.0 is a way better option over the 318 imho.. not a big fan of the 5.2

I'd prefer the 5.0L myself. I'm very familiar with them and I feel pound for pound and inch for inch a SBF cannot be beat. But all of the hurdles involved makes it a project that would be better suited to a longer term. If there were a way to bolt my 241OR to an AOD I'd find some way around the emission issue. Like running a '98 ZJ computer to run the 5.0? Or register it in a county that doesn't require emissions. As it stands though the 5.0L doesn't seem like the best way to go.

B
 
I don't know yet about the physical dimensions as it goes into an XJ, but I do know about swapping the Magnums into Wranglers. I have a 5.9 in my TJ, a buddy has a 5.2 in his TJ, and I'm helping another friend install a 5.2 into his YJ. But I do plan on swapping a 5.2 into my wife's XJ sometime.

The great thing about the Magnum swap is that is meshes so well with the Jeep electronics. The PCM mounts in the same place as the XJ, the Dodge PCM will run all of the gauges, and the Grand Cherokee auto trans shifter mounts right to the XJ shifter.

One thing you need to make sure of, is that you need to make sure you use a 98+ Dodge PCM. The 96 and 97 does not have the same BUS as your 98, and none of the gauges will work.

And on my TJ, and a ZJ V8 fan fit the 4.0 shroud with a modified TJ radiator (outlets are switched), I used mounts from AA.

I used a Stak D300 Replace-A-Case to get the smallest t-case and longest driveshaft I could.
 
XJ

to the OP why not do a 360, extrenally same as a 5.2 but with lots mo power

Bob has enough problems breaking chit with a 4.0l, not sure why he needs a V8! :D
 
Do some searching for articles written back in the mid 1990's in 4-Wheel Drive and Sport Utility Magazine. They built an XJ and swapped in a Chrysler V8, either a 360 or 318 (I can't remember).

It was a pretty tight fit and required a new radiator and motor mounts. They used the V8 and matching transmission from a similar year Dodge pickup and used the t-case from the XJ. They didn't talk much about the electronics.
 
NOT in a Jeep, it's not.

Really? Not that I've driven / seen a Magnum engine in a Jeep but the power figures don't look like anything special. More than that, the light research I've done doesn't show squat for power adders without camming it or going back to a stone-age carbeurator.
 
No modern US V8 is lameass, sorry I just don't agree. As for the 5.0L specifically making a drivable 300HP from one is a breeze. And for that it's about 60lbs less than the 4.0L and physically smaller than any modern V8. An all aluminum LS may be somewhat lighter but for an Iron block and heads their hard to beat.

The 318 is a fine motor too though. Up until the Magnum the 318 was the "low line" engine and therefore mostly ran 2V carbs. It has as much potential as any other V8 out there. With the Magnums the motors were much upgraded and even though there is plenty more potential they are good motors out of the box.

For my needs as stated in an earlier post I break plenty of stuff with the 6, so why do I want a V8? The fact is that even a 4 cyl has enough power off road. With a 4:1 low range and 4.88 gears you don't need tons of HP or torque to get a Jeep moving off road. My Jeep, like me, has put on weight over the years though. I scaled it a few months ago and it came in at 4930 lbs with no spare tire and essentially unloaded. Throw 3 more people in there and enough gear for camping for a week and your looking at just south of 3 tons! I've always felt the 4.0L was too weak for the XJ if you tow much of anything or load it up with a lot of weight, so a V8 is just what it needs IMHO.

B
 
XJ

to the OP why not do a 360, extrenally same as a 5.2 but with lots mo power
exactly what I am looking at right now.

OP, aiming for MT or AT? I wouldn't put a Chryco AT in anything. Dodge Dakotas and Rams come with 5.2s and 5.9s and various aisin and NVG 5-speeds though. My ideal swap donor (which I am shopping for, not doing the swap for a while but keeping my eye out for cheap donors) is a 94-02 Dodge Ram 2500/3500, preferably 3500. I found one for 1500 bucks with a plow and dump bed but it sold before I could get the cash together for it. If I'd picked it up, I would have a 5.9, NV3500, and NP231DHD (iirc) to swap, and a pair of 60s plus a plow and dump bed to sell to partially cover the costs.
 
Fair enough :laugh3: For some reason I thought it was a 3500. Got confused with the 5600 that I seem to recall only being available on diesel models.
 
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