Hey guys, well CJ fever has gotten to me again, and so I drug home a 86 CJ7 a few days ago. It has no motor or tranny so first things first is to find something to put in it. I had a cj before that I put a 5.0 sbf mustang motor in, but I really want to do something different. Don't get me wrong the 5.0 was more than enough power for the little cj. Now what I want to do is put in a 4.6 or 5.4. Preferably the 5.4 simply for the wow factor. Anyway, I don't know much about the modular motors, so I came here to get some help. I don't want to put in any kind of specialty mod motor in it. I would rather run a mainstream mod motor. Like one out of a f150, expedition, mustang etc. However, I don't know what years to stay away from and what ones would be a good choice. I seam to be gravitated toward the 5.4 with the 4r70. I know i will probably have to stick with the automatic because of the lack of availability to adapt to 4x4 manual trannies. So, what is your opinion on the motor and tranny I should be looking for. Also I need to figure out how I will get the stock EFI stuff to work so any help there would be appreciated as well. If any of you know of anybody who has done this, I would love to talk to him. Anything will help at this point

Thanks guys. I will also post this in the 4.6 5.4 forum.

 

Hi there:
I'm an old hotrodder and have seen a lot of engine swaps.

A problem with the mod motors for swapping into older or smaller cars is that they are wide and huge. I believe a 5.4 is like 28" wide compared to 22" for an old 302...the mod motors are larger than many of the traditional big blocks. Fitting stuff in is gonna be a huge headache--stuff like headers won't be fun.

I don't know what you're working with in terms of Jeep engine room, but certainly a traditional swap has been the small block Chevy. A 383 would be a torquey beast. (This is a 400 crank in a 350 block as I recall.)

For something different, the older Jeep CJ's used to use the 304 AMC V8 which was the same size as an old 390. (I owned a couple late 60's 390 2-seater AMX's.) I think the stock or common transmission with those was the Chrysler 727; not sure if an OD would work. If you can find an engine, it probably won't cost a lot of money although parts are gonna be getting scarce. And there should be factory parts to put in an AMC engine. A hot 390 or 401 AMC would be a beast of an engine...even a 360 would be great (note that this is not the same engine as a 360 Mopar).

I'm sure a 340/360 Mopar engine would also be a nice fit....

Good luck. Although I really like the 4.6/5.4 mod motors (I have an '02 E150 that I bought new with a 4.6, now with 115k miles) I just don't think they make sense for swap material.

George

 

I am a ford guy so the only options for me are going to be a ford transplant...other than maybe a 4bt, but they vibrate to bad. Anyway, so there is no way I am putting in a chevy. Everybody and their neighbor does that. Really the only reason why I want to put a 4.6 or 5.4 in is because I have heard of nobody doing it yet, and I want to learn about these motors. However, I just bought a 351 and zf5 speed just in case I can't put a mod motor in. I measured my wifes expedition 5.4 and I think the jeep would need some inner fender work, and the steering shaft would be in the way. Of course I think the headers would have to be custom made too. I found a local scraper that is getting in a car with a 4.6 soon and he said I can borrow the engine for a while to mock it up. So I will see how that goes.

 

Good luck with your project...seems like you should be working with a first gen Bronco instead of a Jeep.

IMO, the mod motors got overhead cams because of Ford policy, not because of any functional reason (they are not ultra high revvers and the 5.4 in particular is way undersquare with a really long stroke). I think your 351 or another big-inch small block (Ford or otherwise) would make far more sense than a mod motor. If you do go with a mod, I'd suggest you try to find an aluminum one (from an Explorer, some Expeditions) just for kicks.

I also like the idea of an old AMC motor given the CJ7 lineage, but it's your project.

Take care,
George

 

If you want a mod motor use a new Coyote 5.0. You can buy the ecu and wiring directly from ford.

 

The Coyote engine is $6-7000...(cough cough). I don't think this is a viable swap despite the availability of wiring and ECU... We are talking about an '86 CJ and probably an old hot rodder with the typical low budget.

George