Sounds like you're having a blast! The fun part is working through all the bugs. Don't fret too much about your MPG they'll increase as you work through everything. My new truck is getting 38-40 consistently now. Trying to estimate MPG gallons on short runs is near impossible, and on the other side of that (not that I'm complaining) but you have to drive a long time on a tank of fuel to get an accurate MPG test. My truck will run 700+ miles on a tank. FTE knows what I'm saying. I didn't notice any change in MPG by changing my t-stat, but I do run a 185 in mine. You'll be happier with the 3.07 gear too and it will add MPG. And get an IC ASAP it will make a huge difference!! Keep us posted.

 

Sorry to here on the glow shift. I really thought it was great to have all 3 in 1 guage but the quality realy wasn't there. ( get what you pay for I guess). To make it (dim) there is a wire that needs to be hooked up to the head light switch. It really doesn't dim that far it would Get a bit annoying at night and after I had it dialed it I found myself putting a rag over it at night. Maybe get creative with some window tint.? Glad to here you have Had some seat time they really are a blast. As far as the cooling fan goes. I ran mine for alot of the summer 80-90 deg. Without 1. including ALOT of wheeling in the mountains and if it every got remotely warm I could Kick on the heater and watch the temp drop. They really do run cool. I hauled 5 v2203 from Portland area to Monroe 200 mi and never even saw the temp guage move. You can ask fte how bad it was squatting though .

 

Hey Rangmar did your glowshift fail? mine is still working. I did hook up the dimmer wire to the old auto trans gear selector light, if it is dimming I can not tell. I heard about your engine delivery. Are you getting any more engines? Any updates on your sport track cummins, I think that will be very nice.
I finally picked a intercooler. 29x11x3, Now that it is on its way I am thinking I may have had room for the next size up 31x11x3. Those are overall dimensions, the core is a bit smaller. I don't know how much more cooling you could get out of the extra 2" of core (22"sq). Well I can agonize over that little detail for a long time. I did manage to move the radiator and condenser aft a couple of inches. it was not that bad, There was some trimming. When I go to plumb in the piping there will be more trimming as well. I might even get to pull off the bumper to get in there.
So in the morning I hope to finish the radiator/condenser mounts, and see if I can get the 3.07 axle swapped in. Hopefully I can get some more road tests in with the 3.07, and just the radiator moved, and make sure the new radiator position and mount are going to be ok. The intercooler will not be here until Middle of next week. Oh and I got a little universal cruise control for the jeep as well.

 

couple of updates. yesterday I got the radiator and condenser moved back about 1.5", I now have about 4.25 for the intercooler. the whole space is 36"x12"x4.25" I am planning a 29x11x3 air to air intercooler , it should be here on Wed.
Today, I finished up the 3.07 axle swap/install. The axle install went ok, but the parking brake cables were different. So that ended up being a rear brake and Ebrake cable swap out, Which is really like doing 4 brakes, because I had to install the old brakes back on the '98 3.55 axle.
Well it is all done and road tested a few minutes ago. I like the 3.07, the speedometer is reading correctly, and the jeep seems a lot quieter at speed, BUT I did not get a exact figure, so the BUT is my EGT's are up quite a bit at hiway speed, I guess the 3.07 loads the engine quite a bit more. Also the boost is up from where it was at the same speed with the old 3.55.
It is still shocking how much more drivable the Kubota is compared to the NA Benz.
Still yet to come the intercooler install, and the cruise control.

 

Intercooler install is finished. I can not tell a big difference in performance, it does feel a tiny bit more powerful. EGT's are the same as near as I can tell. Nice that there is no turbo lag to speak of. But no IAT senders yet, and I seem to have lost my OBDii info, or my reader crapped out. I really liked the OE IAT Better than the liquid adapted glow shift sender.
With the 3.07 gear in the rear and 28.3" tires, and 0.79OD I turn a lot less rpm on the hiway, 65mph is 1900rpm 830egt, 70mph 2040rpm 860egt. 75mph is 2250, 990egt. 80mph is at the top of the powerband I guess at 2300sh. it is pretty hard to data log and drive at the same time
I have not gone fast enough to see whats going on up above 2250 with the egt's . But in 3rd gear the egt's drop off once I get above about 2300; but the engine is a little out of its comfort zone above 2250.
I had a engineering failure on the Aircon crank pulley. I re-tensioned the Aircon belt, and noticed that there was a tiny bit of play in the crank pulley. So I "really fixed it". I discovered that after break in The paint had worn off the splined part of the crank, which let the pulley settle onto the crank snout a bit more. The crank nose was sticking out a tiny bit past the pulley. This let the hold down washer bear on the crankshaft NOT the pulley. So the fix was to back cut a few .000"'s from the back of the washer to give some relief from the crank nose. So the washer would bear on the pulley again. Within a few minutes on the test drive the Washer failed and the aircon crank pulley fell off. Leaving behind the hold down bolt, and a perfect circular little bit of the washer left under the bolt head. At least the bolt did not break off. That washer was over 1/8" thick.
It is still pretty fun to drive. About 250 miles on the conversion so far. I hope to have the cruise control installed in the morning.

 

1150 miles on the conversion still going I just finished up a 700 mile round trip for turkey day about the best MPG has been 34mpg, at 70 mph, with a tail wind That runs about 2100 rpm @ 70. The engine sounds best at 65mph, and 2040rpm.
The only serious problem I had after losing the aircon pulley a few weeks ago was at night, I had a soft fuel line from the lift pump to the filter actually burst. That was a big scary fuel leak at highway speed, I probably pumped about 7 gallons before I stopped. lucky not to have caught on fire.
I am still chasing some vibrations in the cab. I think the Mercedes rubber mounts have settled and are not a good choice. So I am looking for a new rubber mount that will have the same height as the MB mounts. I still have the noise from the clutch, where it is noisy at idle with the clutch out, and quieter with the clutch depressed. I am pretty sure that it is the springs on the clutch friction plate. I think a heavier duty or better quality clutch may solve that problem LATER.
I am going to swap to a 180 degree thermostat to chase some better MPG. The hottest I get is pretty much 150 deg now, and when it is cold out with the heater on I am down to about 125.
I should be able to test out my new Bluetooth OBDII/ smart phone instruments later this week

 

Well I know why I was not happy with my intercooler. I finally got around to checking for intake leaks. I think every joint in the intake system was leaking air. I was a little surprised when I did not get past about 4-5 psi before I could hear the leaks. I tightened everything up, and then I only got to about 10 psi before I started blowing the joints apart where I had made the cuts and did not bead the pipes. Pretty big bangs when they joints give out
I spent most of yesterday making a beading fixture, It worked pretty well, on the pipes that were pretty straight. I had to weld a bead on the bent parts.
I was afraid to leak test at more than 20 psi. But it made a pretty big difference in the overall performance, I am only hitting about 20psi at max boost
Now that I am not blowing most of my boost in the wind, It feels a bit more powerful than it was, the EGT's are down quite a bit, and I can not get any black smoke at all at my current rack setting. I hope that MPG's come up as well.
The MB engine mounts that I used have settled quite a bit, I ordered some new mounts for next week lets hope they work a little better.
all in all it is still running pretty well, I am wondering how long the springs in the clutch disc can hold up, with the noise they are making at idle with the clutch out. Also I am only thinking a little bit about changing the rear gear for a taller 2.73

 

You should be making more boost, I get around 25-27 depending on the temp outside. If you're not getting some smoke you may not be adding enough fuel. I have found that if you cut the fuel back too much your power and your MPG will suffer. I have mine set to deliver more fuel than I need, I simply don't stick my foot in it.

 

Hey Kubotaman thanks for the help. I forget are you running a K03, or the TD04 turbo? I have the TD04. I suppose I can add some more fuel, or at least give it a try, it does not take much to turn the screw. I want to look at the waste gate a bit first, and see when it is opening, or if I can delay its opening a bit. FTE told me a good idea to try and rig indicator wire or string or something on the waste gate that will stick out of the hood, so you can see when the waste gate is opening.
I am thinking my intake pipes and clamps will not hold up to 30 psi. I am pretty happy with the CX racing intercooler, but the clamps they sell sort of suck. I broke the spot welds on 2 of their clamps, and deformed the half of them, while chasing the intake leaks. I had leaks even on the store bought beaded pipes.
I am still trying to chase a annoying vibration on the passenger side, sort of a high frequency vibration that is more noticeable when the power is on, and goes away when the engine is not loaded. I think it is not so much engine related as some chassis component, like a fender liner, or flare, or aircon piping, something simple I just need to find.
Next on concerns. I can not see any smoke during normal running in daylight, and I think the breather blow by is normal especially with the vac pump exhausting in there. But at night when headlights are behind me, I can see I am putting out some kind of smoke behind the jeep. Can't see the color in the dark. I am not using any oil to speak of. I have not done a compression test on this motor. Has anyone else noticed this on a Kubota? I am thinking to try some sort of cleaning oil additive like marvel mystery oil

 

I'm running the K03 and my waste gate is fixed with a rod, it cannot open. You may be having plumbing problems because your pipes are slick. I painted mine, which are exhaust tubing, and afterwards they would blow off. I had to sand the paint back off the ends to stop it. I'm only use standard hose clamps.

Your description of the smoke is normal. My IDI truck acts like that, it is the headlights behind you that make it visible.

Kubota blowby is heavier at idle. If you bring the idle up just a tad you should see the blowby decrease. The vac pump should not affect the blowby as it does not produce any exhaust into the crankcase unless you cause it to consume vacuum such as applying the brake.

Unless you're having hard starts or a miss when the engine starts you won't have a compression issue. When the compression drops on a Kubota they are really had to start and smoke. A good tight engine will start super quick without spinning.

I'm still of the opinion that you need more fuel. You should be able to make visible smoke in the daylight. Just keep an eye on your EGT's.