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Does anyone have or know the dimensions of a XJ/MJ engine bay, considering a powertrain swap and looking to see what i can stuff in there. my jeep is sitting in the woods back at home so i can't measure it until the weekend, any help would be appreciated 

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Nothing set for a powerplant yet, thats why I'm trying to find the dimensions. The idea right now is a fuel injected obd2 Chrysler engine preferably a v8. i know that a 318/360 will fit but if possible i want to go a little newer for more efficiency

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i know that the early model 4.7ls were garbage because ive had to fix my share of them, but i think that the late model ones 09 and newer were supposed to be significantly better with an added 60ish hp. As far as availability around me there are about as many hemis and 4.7ls as there are LSx engines even more so with the magnum engines,  so thats not a problem. I'm not knocking the LS or vortec engines, but I'm a mopar fan and would much rather have a mopar powerplant than a chevy in my jeep.

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Beyond the more awesome Viper source, Dodge and Ford both used V10's in the '90' and 2000's in heavier-duty trucks. The Ford one is based on the mod V8 so has overhead cams and might be a tight fit width wise, (anyone know of a mod V8 swapped XJ?) but the Dodge one is based off the 360 and OHV so shouldn't be an issue. As far as length goes, the 4.0 is pretty long so I don't think that'll be an issue.

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The 2000s dodge v10 would probably fit, it's not much bigger than a 360 (there's a block at school I can measure) but not so much a practical engine in a daily, in my opinion at least. Yeah I'm pretty well set on a newer engine just for efficiency, I'm set on at least obd2 at the very least for engine management. I like the info that obd2 provides and the option to tune the system. And how difficult would it be to cool the engine with a 180 or 160 t-stat hood vents and electric fans? The hemi is something like 3 or 4 inches shorter than the 4.0l, which gives a good chunk of space for radiator and fans

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The thermostat only controls engine operating temperature when the cooling system has not reached saturation.  The frontal area of a XJ/MJ chassis is minimal, to say the least, which is where the problem really lies.  Short of really hacking things up you won't actually get a much bigger radiator in, as if you move it back and make it taller it has to become narrower to fit between the frame rails.  I'm not saying it's impossible, or it won't work, but I am saying it is an issue with many swaps.

 

 

I honestly have zero use for any Dodge/Chrysler engine or management system, so I am biased, and I am saying that despite owning multiple Dodge/Jeep/Chrysler products.  I would hands down go GM.  Something aluminum ideally; there's a somewhat rare 5.3L used in Trailblazers? that is all aluminum.  Or the more powerful LS1/6/2/3/4/7/9/LSA/L76/92 options. Being all aluminum is helpful in the weight department, and more importantly in the thermal management department.  Plus the GM EFI can actually be made to run standalone for very little money and with minimal effort or compromises; that is simply not the case with the majority of the Dodge/Chrysler/Fiat junk.

 

Hell, I'd swap that silly I5 out of the Canyon/Colorado in.

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Thanks for the input about the cooling, that is something that I am worried about with any v8 swap, but the hemi is somewhat shorter than the 4.0l which gives me some room to play around with the radiator without having to hack to much apart. Plus removing the mechanical fan and replacing with 2 or 3 electric fans solves some of the cooling issues. An aluminum block would be nice just for the weight reduction alone but as I said before I have no interest in running a vortec or LS engine with this jeep, I would much rather have a chrysler engine in it because of personal preference. As far as the EFI goes trimming a harness and sending a PCM out to be reflashed isn't more than $4-500 and some time

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Two obstacles, yes, but the ridiculousness is what makes it all work ;). But it can't honestly be any more work than dropping a 4.0 into a Niva. Which is what I'll be doing eventually I hope. I mean, the thing will practically be midengined to fit a straight-six in there, but I imagine it would be easier with an MJ, with so much more wheelbase to work with.

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There is an old Dodge R/T running around San Diego with a Viper V10 in it.  The engine is very tight, even in a space made for a 440 V8.  Lots of work to make it fight properly.  Looks GREAT. 

 

Seem to recall there is a shop in the Pacific North West that does MB diesel conversions on the XJ/MJ. Normally they use the 5 cylinder 3.0 MB 617(?) engine.  But their web site had a picture of one conversion they did with the longer 6 cylinder MB Diesel.  Think they added some space at the front of the engine compartment for the engine length.  Think they quote $10K for the complete conversion, including a rebuilt 5 cylinder MB Diesel.  But the MB diesel should run for 500-600K miles easily.

 

As for the Chevy I5 "Atlas" engine family:  Peter with the Worlds Fastest Comanche was an advocate of that engine in the Comanche.  Only issue was that the Atlas Family of engines is a couple of inches taller than the 4.0

 

If you want the OBD II engine management features in your MJ, why not just use a 96 OBD II engine wiring harness and the correct ECM from a Cherokee?  That will give you all the tuning options you want of the OBD II system and still have the original MoPar engine.  Know this has been done by more than a couple of XJ owners.  Should be a low bucks solution also.

 

Right now, I am paying for a VW TDI engine conversion for the 86 Diesel MJ I purchased in June of this year.  Will not be cheap, but will be dead reliable and can match the torque of a 4.7 stroker with out too much trouble.   For example, my 96 Passat TDI puts out 313 lb/ft and 173 hp with just a turbocharger upgrade and a fresh chip tune. One fellow I know has modified his TDI engine and turbo up to 380 lb/ft and 228 hp.  The car still drives fine on the street (driven to Las Vegas with him) and actually watch the dyno tuning of the engine when it was tuned to that power level.

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