4.0 engine swap

[no1rifleman]

Has anyone done a 4.0 fuel injected swap?

[randall555]

i havent done one but thought about it once had a 4.0 from a 99 ford explorer sport . i think this would be ok if you dont plan on hauling or towing heavy loads

[2ndA]

Seems to me you'd be asking a lot of the little motor. It may make a fair amount of HP but it's not making a lot of torque, and it's doing it with very light components. I'm not sure I'd even want to do it with a 4.3, and that's a lot more motor from a design standpoint.

[randyscycle]

I've owned a couple 4.0L Jeep engines and a couple 4.0L Ford V6's.

I wouldn't personally go through all the work to install either of them into an M715. Both are decent engines, but with an M715 at 5000 + lbs, either one is going to be working pretty hard to haul that much truck around, and for the money and time it would take to do the swap, there are a lot of other bigger, better powerplants available that would provide much more return in power, torque, and driveability.

Plus, your transmission options for the 4.0L Jeep are pretty limited to light-duty AX automatics, or manual transmissions designed for a 2500 lb vehicle. Ford's options are the A4LD automatic which is pretty flimsy, or the manual transmission which I think was a light-duty Aisin-Warner with a pretty high low-gear. 2WD versions are a bit tricky to come by in either vehicle for putting in front of an NP200, and the stock Ford or Jeep transfer cases wouldn't stand a chance in an M715.

[2ndA]

I was going to add, and forgot, that the 4.3 would also have vastly more and better tranny options and even then I'm not sure I'd want to do it.

[moosejr]

I have to agree with WHY? I don't see you gaining a lot. I am running a 292 chevy I-6 right now, ..that is essentially 5.0l, and it is under-powered. The 292 produces significantly more torque than the 4.0 would. If you are only looking to cruise around town, the 4.0 might be fine, but for my purposes, a truck is a truck, . .in other words, I use it to haul loads, pull a trailer, etc. FWIW

[wingtime]

Umm isn't the 4.0 I-6 244 ci? I would think that would be plenty of power compared to the 230. Not a powerhouse but a cool swap since it would at least keep it all Jeep. About the towing a call hauler with a TJ that is crazy. The 715 itself weighs more than the GCVWR of your TJ! My buddy tried towing a ranger on a car trailer behind his Scrambler. A semi passed him on the highway and he lost control and rolled the scrambler and trailer! Just cause you got away with it does not mean its a good idea! I wouldn't even think of pulling a load like that with anything less than a 3/4 ton truck.

[Ronner]

A good, careful driver can tow with just about anything. Should they? No, but you work with what you have. I've towed with my Samurai before - would I have done it if I had another choice - heck no! But it got the job done.
As to the 4.0 - it would work just fine, good torque and all that. It's just if you are going to go to the trouble of replacing the motor & trans then going with something bigger would be better.

[syzygy]

if you are going to go to the trouble of replacing the motor & trans then going with something bigger would be better. (IMHO).

There, fixed it for you! It's all about what the owner wants to do with it! What he's talking about is basically a modernization even swap for stock. Similar power, size, etc., but more reliable, easier parts, etc. Sounds good to me! (That said... I'm going to be ditching gas for fuel...)

[Ronner]

No, you need not fix anything of mine. Take a 4.0 and its' transmission and stick it in your truck. The 4 or 5 transmissions that you will replace each year will tell you that "if you are going to go to the trouble of replacing the motor & trans then going with something bigger would be better."