1999 Jeep Wrangler 2.2L Kubota diesel swap

[redveloce]

I certainly liked this thread, including your methodology, pre/during/after-build. Heck, I joined this site so I could make a pest of m'self.:yikes:

Hi Eddie, no problem I'll answer as best that I can!

1. Have you tracked crankcase oil temperatures? I've looked at online manuals for this engine and not seen the factory heat exchanger many automotive diesels use OEM. Does it have oil circuit supply/return ports?

I don't monitor oil temp and it doesn't have an oil cooler. There isn't a factory provision for supply and return ports, but it uses a standard sized oil filter, so an adapter would work fine if necessary. I monitor coolant temp, EGT, and intake air temp at the manifold. I haven't been too concerned about oil temp, because it doesn't run hot, even during hard pulls over a pass. I haven't mounted a cooling fan yet, and it has not gone over thermostat temp. If it's less than 50 degrees outside, it takes about 30 minutes of driving to get up to operating temp.

2. Were you able to keep the OE oil pan? What material is it made of?

The proprietary Carrier pan that came on the engine won't clear my front driveline, so I'm running a factory Kubota sheet metal 'breadloaf' shape pan.

3. What is the OAL of this engine, fan hub tip to back of block? Height, bottom of oil pan to highest point of rocker cover?

I looked through my documents and haven't been able to find my measurements.

4. Looking at pics and the manual, I have to wonder about the lack of harmonic damper at the crank snout. Do you think adding one would be of value?

I don't think it would make any noticeable difference. Most of the discussions about it that I've found on 4btswaps for other engines have found that adding one isn't noticeable. It doesn't vibrate much at all, the only vibration issues I've had have been engineering issues with the exhaust, different accessory mounts, etc. Just little things that I've had to work through.

I'm coming up on 10,000 miles on the swap, and the refinement is advancing by leaps and bounds. My family was visiting yesterday, and we had four of us loaded up in the Jeep traveling at 70mph on the freeway. The engine was just yawning along with 600-700 degree EGT, and 5-6 PSI of boost. The boost peaks at about 22PSI on a hard acceleration, and I've seen 28PSI on a long hard pull over the pass.

I went to adjust my throttle stop screw a few weeks ago, and realized that the throttle lever wouldn't even reach the screw. The linkage has gone through several minor changes since I originally set it up, and I found that it was hitting a stopper stamped into the bracket for the bell crank. It would get full throttle off of idle, but with the governor stretching out the spring at any higher RPM I was only managing maybe 1/2 throttle at peak! I bent the offending throttle stop out of the way and HOLY CRAP it goes! :Wow1: I think there's a possibility that it would beat the original 6 cylinder now.

I'll be heading over the pass again in a week, and pulling a tent trailer back, so I'll see how it does with the throttle fully functional then!

 

[k9lestat]

truly an amazing build, i think its a great thing. i would like to see that set up in a sami.

 

[redveloce]

Here are some videos that I took last night and this morning while playing around with GoPro mounts. I need to figure out a better microphone setup, but the rest isn't too bad. I have a single turbo off of a 3.3 Cummins on the engine now. The twins had plenty of power, but the WRX turbo went bad and was over pressurizing the crankcase.

Pulling onto I5 North

General driving around

 

[Dan Grec]

That's awesome, thanks.

So smooth and quiet - all the stock guages work. It's the perfect swap.

Are you still running the methanol injection?
What have your MPGs settled down to?

Thanks again for keeping all of us dreaming of a diesel swap well stocked for ideas

-Dan

 

[redveloce]

Thanks, Dan!
I am still running the methanol, and Fuelly shows my 25.6mpg over 30 fuel ups.
I just drove the Ranger that inspired my swap today. He has the same engine and turbo, but much quicker spool and better mpg. We came up with a few ideas to try on mine, but there's always room for improvement

Sent from my SPH-D710VMUB using Tapatalk 2

 

[DreamingOfExpeditions]

In. This is a perfect example of KISS. I like it! As an engineer I see far to many "overkill" solutions when "good enough" is perfect. It meets all your needs.

I'm subscribed!

 

[Overthetop]

Just finished reading this thread. Can't believe I missed seeing it! It has gotten my mind crunching some numbers to see if it would be worth putting in a '95 Geo Tracker that I have sitting around. The 4banger in the Geo is only putting out 99hp, so hp has never been a huge concern on mine. keep up the good work!

 

[redveloce]

The 4banger in the Geo is only putting out 99hp

A friend who swapped one of the Kubotas into his Ranger had it on the dyno a couple weeks ago. I copied/pasted his post from a different forum below.

"98 hp @ 2200
278 ft lbs @ 1800
Hp peaks at 2200 and stays almost perfectly flat to 3000
Tq peaks at 1810 and doesn't drop till 2700 and was at 263 @ 3000"

That's @ the wheels, BTW! His engine is built very similarly to mine, and we're geared nearly identically.

*edit* Here's a video of his dyno time if you're interested.


I figured it was time for an update :sombrero:

I've made a few improvements to mine over the past month. I'd been having problems with the boot slipping off of the turbo that I swapped on about 6 months ago. It's off of a small Cummins, and had a proprietary v-band flange that I had to cut off to use a regular boot. That ended up not leaving enough meat to reliably clamp the boot onto, so I solved that problem by having an awesome local welder TIG weld a readily available v-band flange onto the housing.

The exhaust manifold that comes on these is less than ideal for using with a turbo. It has relatively thin flanges on the head side, and only two bolts on the outlet. I've had some issues keeping it sealed, so I decided to try a stock Kubota manifold from a turbo engine. The turbo manifold has fewer internal obstructions from bolt reliefs, much beefier flanges, is braced with ribs integrated into the casting, has a 4-bolt outlet flange, and maintains the port size all the way to the outlet. I built a new adapter for the turbo, then had the manifold, adapter, and turbine housing sent off to be ceramic coated last week.

Before. I wish I had taken some better before pictures, but this is all that I have.

After

The result is huge improvements in low end torque, and lower exhaust temps. It will pull along at much lower RPM than it would before, boost builds much quicker, and it pulls much harder while staying cooler and using less boost.

Next up is a 3" exhaust, and an intercooler upgrade.

The current exhaust is 2.25", and crosses under the pan to line up with the original Jeep exhaust routing on the passenger side, which requires several sharp bends. The new exhaust will be 3" right at the turbo, and will follow a much more direct route down the driver's side of the Jeep. I avoided this route before because of proximity to fuel lines, wiring, and clutch hydraulics, but now that I know how relatively inexpensive it is to have parts ceramic coated, I'm just going to have the whole thing coated before I ever use it. That plus some strategic shielding will keep the more vulnerable components safe from the heat.

The last performance upgrade that I have planned is an intercooler upgrade. The current intercooler is tiny, and not up to the job once the engine is under load for any amount of time, like pulling a pass, or 75mph freeway with a headwind. I'm going to switch to a much more efficient water/air system with a water radiator in front of the engine radiator. The thinness of the intercooler radiator will allow me to move the engine radiator back to the original mounting location, and the water core intercooler will mount on the engine, making a much more direct and reliable charge tube route.

 

[M35A2]

I just came across this thread and I would like to congratulate you on a great engine choice. While your Jeep works well for your use case (commuting as described) I'll bet it is very much more versatile and I would not hesitate to drive it cross-country.

Did you ever list the source for your Kubota engine? If not, perhaps you can list it.

Thanks also for posting the adapter plans. Most helpful and appreciated.

Oh - almost forgot the most important question: does that turbo whistle?

 

[Dan Grec]

"98 hp @ 2200
278 ft lbs @ 1800
Hp peaks at 2200 and stays almost perfectly flat to 3000
Tq peaks at 1810 and doesn't drop till 2700 and was at 263 @ 3000"

That's @ the wheels, BTW! His engine is built very similarly to mine, and we're geared nearly identically.

So perfect.

My 2.5Ltr TJ that I drove to Argentina only had 120hp and 140ft. lbs at 3,250rpm at the crank.
The joke's on all the people that said your 2.2 would be horribly underpowered for the TJ.

GREAT work!

-Dan

 

[redveloce]

I just came across this thread and I would like to congratulate you on a great engine choice. While your Jeep works well for your use case (commuting as described) I'll bet it is very much more versatile and I would not hesitate to drive it cross-country.

Did you ever list the source for your Kubota engine? If not, perhaps you can list it.

Thank you! I hope to do something very similar to that this year (North to South).
I got my engine from a friend who resells them after they've been pulled from the refer units. Check out the engine conversions section on the Diesel Bombers forum, he's Rangmar on there. I can also PM you his number if you would like. Also, that forum is turning into THE source for info on these swaps, mostly from those of us willing to break a few things to find out what works and what doesn't.

Oh - almost forgot the most important question: does that turbo whistle?

So perfect.

My 2.5Ltr TJ that I drove to Argentina only had 120hp and 140ft. lbs at 3,250rpm at the crank.
The joke's on all the people that said your 2.2 would be horribly underpowered for the TJ.

GREAT work!

-Dan

Thanks Dan, that means a lot! Your trip was a huge inspiration for us TJ enthusiasts, and something I hope to replicate someday.
I found a dyno test from a 2.5L TJ a while back, and it was around 90HP and 113ft lbs at the wheels. I had a '97 2.5L before this and I thought it had plenty of power, so I'm very happy with how this is turning out!

 

[Dan Grec]

Thanks Dan, that means a lot! Your trip was a huge inspiration for us TJ enthusiasts, and something I hope to replicate someday.
I found a dyno test from a 2.5L TJ a while back, and it was around 90HP and 113ft lbs at the wheels. I had a '97 2.5L before this and I thought it had plenty of power, so I'm very happy with how this is turning out!

Go for it! The diesel will be ideal.
Speaking of which, how's your mileage these days?

I'm still researching and learning about my options for a diesel in my future JKUR, and I'm hoping for ~30mpg. Guys are getting that in G-Wagon / 6-speed swaps.
That will save me some nice coin on the road compared to the 20pmg of the gas TJ.

-Dan

 

[redveloce]

Speaking of which, how's your mileage these days?

I'm still researching and learning about my options for a diesel in my future JKUR, and I'm hoping for ~30mpg. Guys are getting that in G-Wagon / 6-speed swaps.
That will save me some nice coin on the road compared to the 20pmg of the gas TJ.

-Dan

My average is sitting around 26. My last tank was around 28, my best was just BARELY under 30, and my worst was just over 23. It only seems to drop below 25 when I have a problem like a boost or exhaust leak. I was keeping track with Fuelly, but they don't have an option for gearing/tire mileage discrepancy, and I was only using it for illustration purposes, so that kind of eliminated the point of doing it. I'm hopeful that the huge thermal efficiency gains I've seen from the new manifold and ceramic coating will translate to better mileage as well.

I know a lot of people with TJ conversions have trouble breaking 30, no matter the swap. Most high numbers you see are just the outlier fill ups. I found a diesel swap a while back where a guy swapped a perfectly running GM 6.2 diesel that was getting 24mpg in the 5000lb donor truck, and ended up with 16 once swapped into the Jeep. That said, I've heard that the JKs are a big aerodynamic improvement over the TJ.

 

[M35A2]

Thank you! I hope to do something very similar to that this year (North to South).
I got my engine from a friend who resells them after they've been pulled from the refer units. Check out the engine conversions section on the Diesel Bombers forum, he's Rangmar on there. I can also PM you his number if you would like. Also, that forum is turning into THE source for info on these swaps, mostly from those of us willing to break a few things to find out what works and what doesn't.

Thanks - please PM his link and/or number. Much appreciated.

 

[Krytos]

I know you're in the PNW, which doesn't make this sort of thing a necessity, but one of the sticking points on conversions here in Florida has always been A/C. Now I know the 2.2 is WAY smaller than the engine it replaces and there's a lot more space in the engine bay as a result. Have you given any thought to the mounting of an AC system in it?

I'm thinking a mount coming off the side of the engine with a second pulley piggy backed on top of one of the existing belt pulleys would probably be able to pull it off. From there it's wiring the AC lines and all that.

(I'm just spitballing)

Also, hypothetically of course, lets say I wanted to call up the shop that made the transmission mount plate you used, would they be able to recreate it/ adapt it for the NSG370?