OP
MPG, torque where its needed, reliability, simplicity, cooling, fuel storage, less wear on parts, etc.
And the fuel is combustible rather than flammable.
I found a R2.8 Cummins Jeep on Craigslist
- Thread starter BugoutJeep
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And the fuel is combustible rather than flammable.
OP
Unacceptable mouks
TJ Enthusiast
Why aren't you allowed to have them? Because it runs on diesel? I see a lot of motor swaps on this forum, in my country we basically can't modify anything on a vehicle, even longer springs or bigger tires need lots of paperwork and cash and a new vehicle inspection to be road legal so we can only dream about motor swaps.. But most cars run on diesel here, and of course every motors are different but my 4.0 TJ has more torque than any diesel engine I drove. What kind of MPG do you get?
OP
Yeah generally civilians can't have diesel except in what may seem like large trucks, which we have a lot of. Before the swap I averaged low teens and now low to mid 20s.
Do you mean HP? Because gas engines tend to be much quicker. Diesel typically doesn't have that fun high HP if you like passing people. R2.8 is probably about as fast accelerating as the 4.0. The 4.0 can't maintain highway speed in your highest gear like most diesels cuz it has less torque.
Unacceptable mouks
TJ Enthusiast
Thanks for the clarifications, maybe I'm lucky but I get around 20mpg and I live in the mountains, my current tires are small though. And I have no problems on the highway maintaining 80mph. The diesel cars I'm comparing to are Honda CR-V, Toyota Rav-4, Hyundai Santa Fe,.. and my TJ feels like it has more torque and HP as well
OP
I had some bigger than OEM, heavy and knobby tires, that combination also hurt my gearing which really wasn't good for the stock setup either. The 4.0 is a great engine for reliability and performance. I would venture the 4.0 mechanically, if new is probably more reliable than my r2.8, considering turbo, timing chain and maybe some other stuff. It's just simple. However if anything with a sensor or ignition or cooling or fuel has an issue, you may be stuck.
I use my Jeep more like one would use equipment and I deal with muddy, soft, steep areas, with sharp stuff in the ground and I've gone through enough tires that I just stick with mud tires and I pay a penalty on tires and at the pump so I can get home with much less walking.
And yeah I think the engines you're talking about are likely small and/or tuned down. I'd still probably take them, but I'm a contrarian by nature and tradition.
gg1
TJ Enthusiast
gg1
TJ Enthusiast
I would rather have my straight 6 for sure. I don't have any idea why a diesel would be that interesting in our little Jeeps. I like Mercedes diesels because they don't rattle and make so much noise, but not a fan of others much.
OP
Trust me, don't mess around with automotive type diesels
. I love the straight 6 and the 4.0 is one of the best, but a modern diesel beats it in every single way. My engine is quieter and rattles less. I did screw up and did polyurethane body lift, so I get some vibrations at idle, but there's nothing once I'm moving. I have no exhaust and it's quieter than my 4.0 with the OEM looking exhaust it had on it when I acquired it. There is the tone from the turbo you notice around that starts around 1,500 RPMs and gets a little louder up to around 2,400 RPMs, but I don't think it's louder than the tires or especially the wind on the highway. I love a TJ and I really liked the 4.0, but the realization that if I went on a trip, it was cheaper and faster to tow my Jeep with my truck rather than drive it, kinda soured my relationship with the Jeep (I don't know why, but I guess I didn't like being confronted with the fact that my Jeep is a toy bugged me). The 4.0 is ok on fuel when it's stock or with a bit more gear, but a Jeep like that isn't capable enough for me. I need at least a tough side-walled knobby tire and with 29s I'm bouncing everything off of my gas tank skid plate for common ditches I go through. It just annoyed me to have to always pay attention to gas stations and to deal with gas cans holding one of the most annoying fuels around. And having to constantly shift when on the highway and it seemed to be such a struggle to tow, that I wouldn't do it unless I never had to go over like 45 mph.
And eventhough it's a great gas engine, it requires delicate stuff or else it won't operate and in some cases it will operate, but you'll be doing more damage. Most CRDs have a portion of the delicate stuff, but they will run in a mode that just doesn't allow for much power. And when your fuel system has a light oil going through it rather than something corrosive, stuff just tends to last longer even at extreme pressures if you keep it filtered. Gas engines require a perfect balance of fuel and oxygen time and spark or else bad stuff happens and therefore it must have perfect conditions or stuff goes south quick. In a diesel, as long as there's some fuel in any amount of oxygen and enough compression to start ignition, then that cylinder will contribute to the powerstroke. If a cylinder doesn't have compression or fuel, it doesn't matter that much because the engines are designed to handle so much pressure that typically an imbalance under less power is within the limits of a perfect system at max power, but that cylinder won't contribute to your power stroke and there will be a bit of an imbalance. That imbalance at a low RPM isn't as harmful as it would be in a gas engine which must spin faster and for that perfect balance, everything must work and more fuel/energy is required just to keep that system spinning.
Only in rare circumstances will any engine swap make sense financially and some of us toss that into the equation, but in reality we just want what we want 99.9% of the time. The only way I kinda "saved" money besides a few bucks here and there at the gas station or oil change, is that I didn't go buy a brand new vehicle (and yes it would have been new, because we have very few diesel options used) and for some reason new vehicles make me feel neutered. Yeah maybe I'll look cooler and go get a straight bill hat, pay someone to cut my hair, grow and maintain a beard, buy sunglasses not from an Army surplus store, wear shoes that don't have holes in them, but that just isn't me.
Heck, I'd be willing to fly to KY, drive the thing cross country to OR and fly home for less than the $2k people are saying it would be. I've done it before with a vehicle. Plus I need an excuse to get out of town! Also never been to Oregon, so I could take that off the bucket list! (I'm also not saying I would do it for free either though, ha ha)
Chief Brohician
'98 TJ Sport '11 Extreme Camper '18 JLU Sahara
Supporting Member
Lifetime Supporting Member
If my 4.0 craps out I would spend the coin to drop in the R2.8T.
OP
So you're saying you're never going to buy a R2.8?
My 4.0 wouldn't die. I just had to jump the gun a bit.
Chief Brohician
'98 TJ Sport '11 Extreme Camper '18 JLU Sahara
Supporting Member
Lifetime Supporting Member
Yes and no. When I get ready, my 4.0 will crap out. One way or another. Just have to make it look like an accident. Maybe the oil pan will get punctured on a rock. 2.8, lift, tires, and skids. Think big. In reality, it will be after I retire (in 4.8 yrs I will 20 yr army reserve, not full retirement). I just had my brother go pick up my Jeep extreme camper. I would have picked it but I’m deployed. So if in the next 4.8 years I deploy again I will just bite that bullet and just buy it. I will have that extra loot to make that leap. The other idea I have is to find a blue ‘08 JKU Rubicon (stock). Drop that dog of a 3.8 and slide the R2.8 in it.
OP
Yeah that's a hard choice between the 2. The install will likely be a bit rougher on the JKU, but that may depend on your comfort with vehicle electrical systems and diagrams that don't match what was installed. The longer wheelbase, for the JKU would be pretty useful, I'd think. BTW I don't think there's a kit for the JKU/JK, so you'll be doing much of that solo.
I like the look/feel of the TJ/LJ stuff more than the JK stuff. I feel like the options to get the TJ/LJ moving well and some towing, etc requires either forced induction and all that comes with that or an engine swap of some kind. An empty and lightweight TJ with nothing but a bit larger tires and a proper gear ratio is great too, but once loaded, I still feel like they are lacking and add in towing, or how picky they are with gear/tire combos.
Plus I feel like a newer JKU with the Pentastar, at least has enough power/torque to not suck. It's a plentiful engine, so just get another one when it poops the bed. I'd prefer diesel for all the reasons mentioned, but it's the same way I feel about my ZJ with a V8, it's plenty good enough that I'm not going to go through that hassle. The TJ with the 4.0 just wasn't enough engine for me and stuff I liked to do. Even the stroked 4.0s get too complicated for me, but maybe something close to a 5L with the more simple tech/design of the 4.0 and I'm not sure I would have done the swap. I probably would have though.
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