1999 Jeep Wrangler 2.2L Kubota diesel swap

wADVr

Adventurer
Here's the Jeep
IMG_20120713_163529.jpg

This spot looks familiar but cant put my finger on it. Where is this?

Great job on the swap! I am surprised such low HP is working so well. Any ideas what tire you are going to go with to balance RPMs and weight/power?
 

UglyJeep

New member
This sure beats the 2 cylinder kubota engine my grandfather put into his little '72 Suzuki LJ10. I'd imagine your set up has a better power to weight ratio (and his little tinker toy climbs like mad).

I want to drop a little 4 cyl oil burner into my jeep...
 

redveloce

Adventurer
This spot looks familiar but cant put my finger on it. Where is this?

Great job on the swap! I am surprised such low HP is working so well. Any ideas what tire you are going to go with to balance RPMs and weight/power?

The pond at the top of Rainy Pass, on Smithbrook Rd off of HWY2 on Stevens Pass.

It's not about HP, it's about torque. It pulls better than the 6-cylinder in the RPM range that I'm in the most. The 'advertized' power of the 4.0 was somewhere around 190 (they usually dyno in the 140s at the wheels), but that is turning almost 4500 RPM.

I'm not sure what size tire yet. I'll have to do some calculations, but they'll be 31" or 32", 33" at the absolute max. I like my wheels, so the tires can be 10.5" at the widest. I prefer 9.5".
 

Dan Grec

Expedition Leader
It's not about HP, it's about torque..

So many people are hopelessly confused by this because of all the marketing over the years about "it has 200hp" etc.

HP is just calculated as Torque*RPM anyway, so it's not "real" in any sense.

Torque is a direct measurement of how much turning force the engine is actually generating.

Without forced induction (turbo, supercharger) the only traditional way to increase torque was to make the explosions bigger i.e. more engine displacement, which is why American engines are so big.
For years, they just kept making them bigger (not better) to get more torque.
More recently, computer controlled values (VVT), inlet runners, exhaust runners, etc. have improved volumetric efficiencies a lot, meaning you can eek out torque increases without increasing the size of the engine. Not surprisingly, this results in changes like we've seen at Jeep from 4.0 -> 3.8 -> 3.6 liters. The writing is on the wall for engines to keep getting smaller and more efficient.

---

I find the really interesting cases to examine are engines like the original 2.0 in the Honda S2000 - the highest specific power engine ever in a production car (power per liter of engine displacement).
It was difficult for average Joes to drive (like a sports motorbike) because the torque curve was a huge spike, which means constant gear shifting to stay in the power band.
Sure it had lots of power on paper, but that didn't translate to usable power at all.

The next model had a bigger engine (2.3 I believe) and actually made less power - because they flattened out the torque curve, making it way, way, way better to drive.

-Dan
 

redveloce

Adventurer
:26_7_2:

I had an MR2 Spyder with the low HP 1.8 from the Corolla, but it had a nice torque band for a small 4-cylinder. At one point I found a good deal on a 2.0 S2000, and decided to give it a drive to see if I wanted to trade. After driving the S2000, I couldn't wait to get back in my Spyder! It was USELESS in any normal RPM range, and only showed the power if you ran the crap out of it.
 

redveloce

Adventurer
Here is something that I just remembered that anyone thinking about doing this swap needs to know.

The factory Jeep 4.0 crankshaft has a larger hole than the pilot bearing size, requiring an insert to fit the pilot bearing. This is to accommodate the nose of the torque converter in an automatic application. My crankshaft/flywheel adapter was designed without this insert to make more room for the bolts. The pilot bearing fits directly into the adapter, so it doesn't have a large enough hole for the nose of the torque converter in an automatic application. It may be possible to adapt the design by just boring the center hole out to the size needed for the torque converter, but I don't know the dimensions offhand, so it may be necessary to add thickness to the adapter if making the hole larger would interfere with the Kubota crankshaft bolts.

100MEDIA%24IMAG0527_zps86db4171.jpg
 
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UpTheCreek

New member
Well, I bet it's got more balls than my automatic LJ at 15 mpg.

GREAT project, thanks for sharing it with us. Someday it'll be more than a pipe dream for me.....
 

jscusmcvet

Explorer
OK, so I just read through this whole thread and...

No, I don't get the wet suit picture but you kids these days... :ylsmoke:

HOWEVER, this may be the coolest modification to any jeep I have seen. Really... are we worried about HP in our jeeps? I marvel at the guys who say "I was doing 80 on the highway"... this is a jeep and like has been mentioned, the best of the breed perhaps, the wwII jeep we all grew out from was light, simple and got the job done... sounds similar to this, except the simple part of getting this done in a way that works... now that it is done, I imagine it is simple...

I am nothing but envious and impressed.

As for the naysayers... well there are snobs in every subculture I know of... remarkable how it might not be the "right"... beer, wine, coffee, music, clothes, workout... thought you left that all behind in high school, but here it is again... one day I will be one of the expo cool kids who can afford to pull up stakes and take far off adventures... :bike_rider:

Until then I will be earning a living, raising my kids, putting them through college, working and hunting my land, riding my MTB and building and using my jeep the way I want and can afford. Never been a cool kid, never will I guess...

Sorry for the hijack and rant. I love what you have done here.
KUDOS to you sir, what a great bit of work that fits you and what you need.

John
 

redveloce

Adventurer
Now that it's on the road and seems to be reliable, the next steps are refine, refine, refine.

One area that needs to be addressed is sound dampening. Not insulation specifically, the engine is actually pretty quiet, but dampening the panel vibrations from the low RPM torque. The Jeep body has a lot of single wall flat panels, which all turn into giant speakers at certain load and rpm ranges. It's not actually very bad, but I'm a perfectionist. I know of some great cheap alternative sound dampening materials for the interior, but I haven't found anything that works well around heat. It may not be necessary, but I can see the hood move with the resonance, and I can only imagine that it's contributing a fair amount to the noise.

Does anyone know of a stick on Dynamat type sound deadening material that will work for hot environments, like under the hood? The heat probably won't be a huge issue, there is a plastic part on the inside of the hood directly over the turbo that shows no signs of seeing any heat, but I'm mostly worried about the adhesives coming loose in the summer and dropping the material onto the engine.

Imagine if this was on the underside of the hood!
fatmat2.jpg
 

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