V8 Swap, Diesel?

BugoutJeep

BugoutJeep

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Everybody loves the V8 in the Jeep Wrangler, but I've got access to a spare Jeep and an older 7.3L IDI Turbo V8 and transmission from a 1 ton Ford truck. I do want the Jeep to be a diesel.

This is essentially going to be a massive build, if I can even get close to pulling it off. The wife wants a Gladiator, but I'd love to have a spare 1 ton truck (and not part with $60k and yeah the one I'd get would probably cost that much for a diesel Rubicon if available), love to kill 2 birds with this thing.

If there's a way to pull it off, I'd like to find a wrecked JKU and steal the rear doors and probably that tub section and scab it in, stretch the frame and add a short flat bed. I'd have to run 1 tons and 1 ton suspension.

How feasible is fitting that monster engine and transmission into a Jeep tub/stretched frame? I'm not against ditching the turbo, but obviously I'd prefer it. I won't be towing anything massive. Max towing would be 12k lbs, maybe and it'll be all leaf spring suspension, which isn't ideal, but the donor is a YJ, obviously not YJ springs either.

The YJ is sentimental so I do want to use it. I've got the TJ and a Willy's CJ for Jeep stuff, the wife wants something she can get her kayak(s) on quick and easy, but she's completely against towing for some reason.

Let me know what you all think, it's been slapping around in my head all day, after talking with a guy at work with some stuff lying around. I figure it would probably be easier to fit a tub onto a 1 ton frame and cut it for length, but I just think it would be really cool in a Jeep. I'm not even sure how I'll do a radiator for that engine either. I will probably not add an intercooler and may try for a deeper radiator, but an intercooler might be nice.
 
I had an '87 F-250 with the 6.9. As I recall, the 7.3 was a bored 6.9. That engine is HUGE - do you think it has any chance of even fitting? And the weight!

I have a pipe dream of an old GMC Big Block V-6 - either a 305 or a 351 most likely - in a Jeep. But the weight, and maybe even the size would be problematic.

I'd be interested to see what you come up with for sure!
 
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I don't have my hands on the engine yet and don't exactly know the size. Kind of wondering if anyone has seen one. I've seen, on the internet, a 6BT wrangler.

I know the steering and suspension of a Jeep, isn't going to handle well at all with a setup that's probably 800lbs heavier than the Jeep drivetrain.

Any ideas would be welcome btw. My dad does have a truck with this engine, so I may go look at it sometime and try to figure out the dimensions. I do think I'd move the batteries from the engine bay since I want to say it's 2 group 31s, so I'm not sure where those would go under the hood. Just to mention a tiny problem
 
I've been planning some more on this build. I'm really annoyed I can't seem to find a print of this engine, but I've been looking at 6BT swaps and stuff and think it may be doable. I know these are big engines, but I've seen big blocks and stuff swapped into Wranglers too, so I kinda think it's possible.

I'm thinking of breaking this build into stages and at every turn I'm going to compare the strength of brackets and frame of the Jeep vs a standard 3/4 ton.

But I think stage 1 would be just as a proof of concept ie moving under its own power. This will probably not even be streetable, but just to make sure the engine fits, how bad are engine vibrations, how loud, is stuff too close, etc. I figure that'll be around $5k just to get the thing in there and somewhat plumbed and probably with a radiator that is too small and probably no intercooler or any luxuries.

Stage 2 will probably be stretching and adding JKU rear doors, door frames and probably rear seats.

Stage 3: If the basics feel right then it's time to build or order 1 ton built axles with braking equivalent or better than a 3/4 ton truck and then steering and suspension stuff will have to be figured out. The axles seem very pricey, but I think I've read that I can swap around some leaf components from different trucks to get the proper lift and rates I need and I'll then I'll probably get some adjustable dampening shocks for the proper lengths and stuff. This is not going to be a mean trail machine, so I won't have to be too crazy with anything, but just be a good farm truck that's fun around town and not a monster sized vehicle my wife can't park.

I'm dying to know the dimensions. I'll have to go check out the engine and the F-350 engine bay to even guess where my problems will be. If it seems feasible I could actually start the build close to the spring. Too many projects, but I've really wanted a slow build that I can take my time with and do my own designs, with the help of others and try to save money where it counts. In my R2.8 build, I needed my Jeep back and its taught me a lot of stuff and much of it is that I wish I had been able to slow down my build and do a little bit more while it was torn apart, rather than rushing. Most of that rushing was excitement though.

Btw, my estimate right now on this build will be around $20k and 400+hrs, not including the Jeep, but over several years, that's not crazy (to me anyway). I might be able to convince the wife to jump on board at some point too. If not I'll probably have to import and rebuild a Toyota Hilux, which she seems to like the idea of more than a 1 ton truck to drive around. Hoping I can get the small truck/1 ton in this build. Though I'm probably not going to try and pull anything 12k lbs. At that point I'll probably just hire someone if my truck is down. I tow around 7k lbs more often, love to be able to do that with this build, obviously the trailer will have brakes, though those don't seem necessary in my truck.
 
AidenC said:
the 6bt would be an easier fit than a 7.3 idi.
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I'd love a 6BT, but the price is crazy high right now for those. I'm not sure I could find one even in questionable condition for under $6k.
 
AidenC said:
how is 2.8 cummins? That is a swap i'd like to do in the future.
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Love it. It won't make your Jeep fast, but it has the right amount of torque in the right spot. And the MPG is a nice addition. There's obviously positives and negatives vs other setups, but it's a great daily driving vehicle. Most of my issues I've had, just come from having a 23 year old Jeep that I still don't understand why anyone would put 3.07s in an axle.
 
I might add that I think, if there's a chance the 7.3 can fit in the chassis, that I can get the Jeep to move under its own power for about $5k. If I start with anything else that size I figure I couldn't get any kind of 1 ton(ish) driving for under $10k. At that point, pretty much everything will be equal, but there's something about having a vehicle that can be driven that eases my mind about ultimately dropping $20k and weeks of work to get right. Also if I can get the body to look right, the wife might start getting excited to see it finished.
 
Btw, its my understanding that I can get the Engine and transmission, which are in good working order for $1k. I'm not sure if I can steal other components from the truck, but often is the case that I may be able to get other components from the truck when it just had a rusted out frame.
 
I do want to use some type of automotive diesel, with some easier to find transmission options.

My dad has a box truck with an international 7.3L, but I just don't have access to it at the moment and I'm wondering about picking this engine up while its available. I just don't see many cheap larger displacement diesels around.
 
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TWiG01 said:
I’m not sure about availability, but what about a 4bt? Probably a much easier fit, similar performance to a 4.0 stock, but much improved fuel economy.
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If I could find a 4bt for the right price it would be a no-brainer for me to go that route, but they tend to be $4k unknown condition. For that price I'd probably just go VW TDI and probably use a lot of gearing to help on the low end torque. I've even thought about compound turbo down the road. I can find TDIs around $1k or less regularly.

Another issue with the 4BT and 7.3 and those type diesels are that they are supposed to be very noisy and bad vibrations in the Jeep, not to mention the front end weight and all that you should do to hold up that weight. 4BT isn't nearly as bad I would imagine. I would need to spend time sound deadening and bushings where I could for a more comfortable ride. Jeeps are simply noisy relative to new vehicles though.

If it wasn't for the initial price, I'd build another R2.8, but I mean actually build the thing. Bottom end and on up, use a lot of gearing to help with the low end, but man it's just a different animal with the large displacement diesels. A 2.8 or 1.9 it's just a high compression 4 cylinder until it spools up, then they just kick you in the seat of the pants with that torque. Tuning a 2.8 to about 250 hp and gearing for the highway to run around 2500 rpms at like 65 or 70 mph, it would probably move really well. I wouldn't trust the 2.8 at 250 hp for long though, without talking to an engine builder/tuner.

A 250 hp 2.8 is just different than a 5.9L 250 hp diesel (I would theorize haven't experienced 250 hp from a 2.8, but I've seen the dyno curves). The torque just peaks so low with the higher displacement, which is just way more forgiving.

If Cummins would release their ISF3.8, that would be a cool engine on paper, though its supposed to have some poor thought out components, but maybe that's more of a Chinese thing, not sure.
 
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Subscribe to see what you end up doing.

if I remember correctly Fred Williams did a 6bt in a JK and needed up having no room in the cockpit due to the sheer size of it.
 
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Maybe I'm the weird one but there's nothing about a diesel engine that would make me want one in a TJ or <4000lb, SWB rig. I love a 12V as much as the next guy, but wouldn't even consider putting one in my RamCharger due to weight and other considerations that make it unpleasant off-road.

While I'm thinking about it, even the 3 guys I know who did 4BT swaps were not happy after the novelty wore off. Two people eventually went LS and the third sold the rig. The 2 shops in the area that did these won't do them anymore either, simply due to low customer satisfaction when all is said and done.
 
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6Bts are long and I think the JKs are a bit shorter. I'm really worried about the height, but mainly the width. If I need a hood scoop to clear, I'll do it. I do know it's a monster, but these Wrangler tubs have a fair amount of room.
 
pc1p said:
Maybe I'm the weird one but there's nothing about a diesel engine that would make me want one in a TJ or <4000lb, SWB rig. I love a 12V as much as the next guy, but wouldn't even consider putting one in my RamCharger due to weight and other considerations that make it unpleasant off-road.
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Well this build is more of a truck build than a normal Jeep build.

However, I never want another 4wd that's not diesel, unless it's just a beater that I can trash at any minute. I don't necessarily like the weight you tend to get, the noise and vibrations from the older ones, but I love the older engines as well.
 
curious to see how it works, I would consider something smaller like a 4BT, R2.8 or VW TDI, I have been contemplating a Stroker swap or a TDI/4bt when my current engine goes, I want to play with Diesel.
 
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Out of your options I'd lean toward the TDI, just because of the price, size and vibrations. I think a TDI is a great option, but depending on your build it might cost you as much as an R2.8, so don't rule out the R2.8, it's a perfect size for a TJ.

I've said it in the past, but I'll say it again, I'm not sure I've seen a diesel engine I didn't want to swap into some Jeep or truck or car. I even eye my wife's Prius as a candidate.
 
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