Kubota Diesel Engine Swap

The kubota Diesel engine swap by overland diesel has me intrigued for my jeep. You get great fuel mileage, lots of torque, same hp and it is very simple and reliable. Only question I have, and maybe you guys can shed some light on it is, the kubota only revs up to 2800 rpm. The L head will go up to 4000 rpm or so. I was curious how the lack of rpms would effect my jeeps wheeling ability. Would the added torque make it so I would be able to use a higher gear? My jeep has a T18 and overdrive, so I have 8 gear choices. Lots of times in say mud, 2nd is too low and 3rd doesn't give me enough wheel speed but 2nd od is perfect.

 

I've heard 25mpg.

 

I had a small Kubota Tractor, Always amazed how much power the little 4cyl had. It could dig itself right into the ground if tied to immoveable object. Drove right out when you let go.

 

More just thinking out loud. Everything costs so much to put one in.

 

I would think you'd need to go to taller gears in the diff's to compensate for the lack of rpm. Otherwise you would have a pretty low top speed.

The kubota diesel would have about the same 60hp that the flathead has. The higher torque is what allows the diesel to make 60 hp at a lower RPM (and throught the 0-redline range it will feel significantly stronger than the l-head), but its still the same 60 hp, and will still only be able to push the jeep against the wind with the same amount of force. It will be more efficient and way stronger around town though

 

Right - power is what overcomes drag. Torque gives you acceleration.

It would be a fun project. However, I'd think you'd be better off with the VW 1.9L TDI than a Kubota. The Kubota is from a reefer unit or something like that, is it not?

 

The only real upside I can see to the kubota unit vs a VW would be that it would happily cruise at maximum power/rpm all day long. Its probably also more compact than the VW engine.

 

Yeah, swap in a Caterpillar diesel with a gas pony engine starter or nothing.

 

Every once in a while these crazy ideas go through my head and then I talk myself out of it.

 

Another vote for VW TDI. I hear 96-98 are the best, due to power vs. simplicity. Very usable power band, and easy to massage them for high output. Adapters are relatively cheap to go to Toyota truck drivetrains (there's your overdrive).

If I wasn't so obsessed with Volvos, I'd definitely be going this route.

 

I'd do an Isuzu turbo diesel, as reliable as anything and Isuzu specializes in diesel engines.

 

6.6 Duramax. Now that would be a great swap. Just saying. You would be able to get a lot of wheel speed in any gear. My Kubota L2250 had a nice small 3 cylinder and it would develop plenty of wheel speed, just took a second to get there. I think the Kubota would be a great little swap. Mine was only 27 HP. Always wanted to try that swap and also thought about the 1.9 TDI

 

This is what I was looking for. Thanks guys.

 

There are some guys on the CJ2A page have done this conversion. They're all really happy with it. Look in the modifications section of their forum.

Put the time, trouble and expense into it and you get a sweet ride.

 

"sweet" is in the eyes of the beholder. It's still going to be gutless. Just less gutless than the 134's. I'm not a big diesel fan unless it's a rig doing some actual pulling. I will readily admit I was a slow learner. Four different Benz diesels over the years and only the 617 turbos were any fun to drive. And even those, before the turbo spooled up, you just about needed to open a door and give them a foot assist. IE-don't plan leaving a stoplight in a hurry-or if you had one in a Jeep-you definitely need some low gears. And none of those Benz's were as maintenance free as any fuel injected Chevy/GMC I've had.

IMO, money much better spent on the ubiquitous sbc or its LS sibling. Just build it for some big bottom end torque. Yep, you will give up a little of the mpg but ohhh so much more fun to drive.
Ironically, my Bobcat Toolcat 5600 has a 134 inch Kubota turbo diesel in it. But it is certainly not something I would want in any Jeep.

 

The big knocks on the VWs are, the best motors are complex beyond the point of annoying. They are also timing belt motors, which never sits well with me. Great power, rpm range and light weight, though.

The common Kubs are simple, like our 134s. Very tractor-esque, so it kinda keeps the spirit. Gearing would need to drop for higher road speeds.

Cummins A2300Ts are similar to the V2200, but more expensive.

For a gasser 4 cyl, I'm very partial to the early 2.2 Ecotecs. I've yet to see a super clean swap into a Willys era Jeep, though.

 

I agree... When I was planning my build I looked at all the diesel options. They're either too big, like a Cummins 4bt or 6bt, or too small like the Kubota and VW... The OM617 looked like a good option other than the length of the motor. That's why I went with a SBC. They're everywhere, cheap, and can make more power than I'll ever need... Besides, I've been out in the hills and couldn't find diesel in my M1008.

 

This is why everyone ends up at the 4.3. Fits great, great motor, great power, yet doesn't overpower the T90.