I'm always wondering about the ultimate multipurpose machine and started forming this idea. I know I'll probably be burned at the stake for this but I'm thinking about the possibility of swapping a 4D55 turbodiesel into a ..... Jeep Cherokee. <img src="/forums/images/graemlins/zombie.gif" alt="" /> <img src="/forums/images/graemlins/ignore.gif" alt="" /> Yes, I said the J**p word.
Here's my thoughts - a 4D55 will bolt up to a KM148 auto tranny, right? Also, it may be feasible to bolt the KM148 up to an NP231 tcase, so it seems reasonable that you could mix & match parts to fit in a Cherokee without much effort. Why would I consider this instead of dropping one in to a SWB Monty? Well, 1) The Cherokee is about 400 lbs lighter, thus improving potential fuel economy. Powell said he's getting 38 mpg in his Ford Ranger. 2) Improved aerodynamics again helps fuel economy. 3) 4 doors improve access to rear seat. I'm a family man & carpool to work. 4) More cargo space. 5) A PLETHORA (love that word!) of replacement parts & accessories. 6) Already SFA. 7) 101" wheelbase is a good compromise of off-roadability & additional wheelbase for towing. 8) The NP231 already has low gearing.
Now for the questions, the KM148 auto does bolt up to the 4D55, right? Or conversely, is the 4D55 bolt pattern the same as the 3.0 V6? This means I could take the bell housing from a V4AW3 and bolt it to the AW4 from a Jeep. Also, does the alternator on the KM148 have a vacuum pump to be able to run heater controls & a brake booster? Or is there a separate vacuum pump on it? Don't you normally get your tach input off of the alternator on a diesel? Would this be compatible with a 4 cyl. tach? Would the 4D55 in combination with 33" tires & 4.56 gears be able to tow about 4000 lbs? And one last one, what kind of fuel pump is required to get the diesel from the tank to the injection pump?
I know Jeep came out with a 2.2L diesel Cherokee in 1986, but it wasn't very powerful or reliable. A Cherokee with a Mitsu heart seems like a good combination. <img src="/forums/images/graemlins/zombie.gif" alt="" /> <img src="/forums/images/graemlins/drunk.gif" alt="" />
Lee,
Here are some comments:
1. I get between 35 and 40 mpg in the Ranger but the rear is geared low. I don't know the ratio off the top of my head and it's at the shop right now fixing a short in the glow plug system. I'm pretty sure it's geared <4.0. My gut is that you will be underpowering the vehicle but if you're not concerned about acceleration, it's probably doable. They put the 4d56 in a LWB Montero with intercooler and turbo... it's no speed demon but has lots of low end grunt. Get up on pocuk.com if you want to get feedback on the 2.3/2.5 turbo diesel in a heavy 4 door vehicle. It's definitely love/hate.
2. Aerodynamics? I'll take your word for that but I've never used that word and SUV in the same sentence before... j/k
3. Yes, you would definitely be better off in a 4 door vehicle in your situation.
4. yes, lots more cargo space than a SWB Montero
5. Actually, the parts for the 4d55T are very rare. Also, it's hard to find people willing to work on it. gas mechanics don't want to touch it. Heavy diesel mechanics might help you once out of curiosity and then never touch it again after busting their knuckles a few times in that "tiny engine bay"
6. Yep
7. Yep
8. not sure
Q1: The 4d55T bolts up to the same bolt pattern as the 2.6 gas motor. You'll need to check to see what bellhousing is on the tranny you find. If it's the same bolt pattern as the 2.6 motor, you're set. You may need a different oil pan or may need to modify it depending on the Cherokee axle and cross member setup. It's the reverse of the 2.6 oil pan.
Q2: The 4d55T on the Ford Ranger has a separate vacuum pump just under the alternator. All of your vacuum accessories will need to use this as a diesel doesn't have sufficient vacuum in the crankcase especially if it has any blow by at all. (then it has pressure instead)
Q3: 4000lbs? 33" tires? >4.0 gear ratio? I don't think you would get very far. I don't think the torque converter could take it. You might be able to move it around town in 1st and 2nd gears... maybe? You'll need to have electric fans and a fresh radiator, water pump, thermostat. You would have to be careful of overheating.
Q4: A small electric push pump by the tank rated at around 7psi should be enough to keep things moving. It's nice when you have to change a fuel filter... easy priming.
My gut reaction: I wouldn't do it. I think you would be very disappointed with performance after spending a wad on a custom engine swap. If you are set on the Jeep and diesel, here's what I would do. Don't worry about fuel economy any more. Drop a GM 6.2L diesel in there with the strongest compatible tranny and tcase you can find. Talk to some local restaurants and get a supply of used cooking oil. Pick it up on Fridays after work or on the weekend in the original containers the oil is shipped in new. Take them home in the trunk, dump them in a drum in the garage. Heat it overnight with a nify little hot water heater element heater. Let it cool. Heat it up again. When it's hot, run it into another drum through a 5-10 micron bag filter and pump it into your fuel tank. Use a heated fuel system and drive all day for free.
If you have the space and don't mind messing with methanol, collect the oil and make a biodiesel processor out of a hot water heater and some other random parts. Convert the waste oil to biodiesel, dump it into your tank and drive all day for about 70 cents/gallon.
If you want better fuel economy, locate a Mercedes 3.0L 5 cylinder diesel engine and tranny/tcase from a Gelaendewagen 300 series. You can find these in the states since they rust out quickly and leave a 500K mile motor and drivetrain with no chassis around it. Put that thing in your Cherokee, build some custom driveshafts and you'll have close to 25-30mpg depending on gear ratio and wheels and plenty of pulling power. Make sure it's a turbo motor. You can pull a turbo and manifold off an old 300DT if the engine you find isn't turbo.
The GM 6.2L should be easier to fit with a *plethora* of spares and probably lots of documentation on the internet on how to do the swap.
One last option for you. Find an old Blazer and drop a 6.2 diesel in it. That should be plug and play since that was an option for a few years in the 80s.
Good luck,
Once you go diesel, you never go back.
Powell
