Hello-
I'm in the planning stageof the Cummins swap I'm going to start in my h1... hopefully sooner than later. I plan to pull the motor/tranny/Tcase out of the H1, do the 3" body lift, get the motor all cleaned and sealed, and see how poorly it fits. If it looks like I can get it in there in the same place that the 6.2 sits and still have access to work on the IP, I may build mounts to put it there. However,it looks likethe height and length of the cummins is going to make it a tight squeeze at best, and probably make certain things I need access to on the motor inaccessable. If that is the case, I may design some kind of lift kit - probably around 6" - that will lower the center section of the axle assembly. This way, I could move the motor further forward than the 6.2 sits, and stand the radiator more upright than oem position. I also plan to get an intercooler in there somewhere... as if I didn't have not enough room to deal with already. I plan on using the nv4500 and dodge tcase behind it, so where the transmission ends up sitting doesn't really concern me... the linkage is going to be a nightmare regardless. Keep in mind that this swap is to make this truck move... I am not trying to retain the "integrity" of the hummer - I.E., I will modify the frame and or firewall if necessary. A couple of concerns - Because of the gear reduction at each tire in the hummer, the cv axles spin backwards. Is this converted from the drivetrain in the differentials, or in the T-case? It would not be fun to put a dodge drivetrain in and have 5 reverse gears. Also, is there anything in the front end going to be compromised from the fact that I will be able to run in 2wd now? I have only found one H1 with a 6bt swap online, and there was very little information - I believe the motor was mostly stock, and married to the stock hummer tranny. I know that I am rambling on, but... I would just like to hear anyone's ideas on this project and/or further knowledge of the hummer that I have not yet considered. Look forward to hearing from you!

 

Haven't done a conversion so not a lot of help to you. Most of the conversion go with a T case with the 2wd option so i don't think that is an issue. The Duramax conversion fits but is tight and needs a 2" lift to work. I think the4cyl Cummins requires the same 2" lift. Not sure on the larger Cummins. Sounds like quite a project. Injunfarian and HMCOleap will probably be able to help you quite a bit. You should also try the search function. There should be a number of threads on the conversion.

 

I am in a planning stage of a cummins swap myself I believe I am going with the 2003-2007 24valve high output 6bt... but I have read many posts and a conversion document some points I have noticed is only need 2" lift(if you have TD) for a 12valve or 2.5" lift(if N/A H1)... for 24valve it is 4 and 4.5" respectfully. Also in the conversion document i have read it was a N/A diesel and he put in a drive train from a 2003 dodge with 24valve high output 6bt also he used the much bigger tcase of the dodge by doing this he had to remove the main tank... So if the tcase you are using is big i'd suggest going with the small atlas tcase they are solid and small will fit nicely and wont need to move your tank..also he has verticle radiator and he offset his rear differential just like the stock H1 front diff... so now he only needs 2 types of halfshafts instead of one... now like i said this info is not from experience just reading other peoples posts and documents.. I hope it helps you as it has helped me...
Also any change of posting pics of your 3 rigs in your sig? id like to see that jeep that can fit 53" tires!!!!!

 

also forgot to mention in the conversion document a new dog house had to be build to make room for the much higher and further back engine block.

 

Those rides must look amazing especially with 53 inch tires

 

That's good to know that the new t-case won't have any adverse effects. I searched this forum and found one other thread on a cummins swap, it was pretty old (I believe) and was pretty vague - I know that this is a project that people don't undertake often. I still haven't even heard of anyone trying to do it with a 5 speed. Sounds like most of what I've dreamt up so far is on the right track though... Injun, I would be curious to figure out why you would need so much more lift for the 24 valve- Unless it is a common rail, they have almost identical dimensions as a 12 valve. Also, there are pictures on my websiteof some of my other projects. Nothing recent on the Jeep in there, but hopefully I'll do a better job of keeping that thing up to date soon. nvcustoms.com. Keep the thoughts coming.

 

ahhh yea sorry it is the common rail.

 

Here is the Cummins Diesel Conversion info for the H1 Hummer! Starting price is $14,900 Here are all the details:

Conversion:

The Cummins 6BT Turbo Diesel engine is regarded as one the strongest and most reliable diesel engines in existence. Many HMMWV and Hummer owners have long stated that this is the engine that should have been installed in the vehicle from the factory. With so many engines having consistently logged over a million miles, it is a true testament to the legacy the Cummins engine has built. Now the Cummins Diesel Conversion is available for all HMMWV and H1 Hummer models. The basic conversion includes a full retrofit to the Cummins 6BT Engine utilizing the stock 4L80 or Turbo 400 transmission. If your application includes the 3 speed Turbo 400 Transmission, you have the option of upgrading to the 4 speed 4L80 transmission. Additionally, all models have the option of upgrading to the Allison 5 speed or Allison 6 speed transmission. The basic conversion is completed in 10 business days. The first 5 days are composed of the mechanical conversion to the Cummins with the last 5 days consisting of full testing including both on our computer as well as on the road testing to ensure a 100% thorough conversion. Each conversion is available in several Cummins Diesel models including all 12-Valve and 24-Valve 6-BT Engines.



Engine:

The Cummins 6BT Turbo Diesel Engine is available in several different models including a 12-Valve and 24-Valve configuration. The 12-Valve model is regarded as a much more basic engine which many people prefer due to its simplicity. The 24-Valve is a newer model engine that offers an increase in performance over the 12-Valve in the stock configuration. Both the 12V and 24V engines can easily build well over 750hp with several in the 1000+hp range. Both engines are extremely reliable and strong and can easily handle over 500hp and 1000ft-lbs of torque in an every day driver application. The engine is a 5.9 Liter in-line 6 cylinder Turbo Diesel Engine. The stock hp ranges from 220hp -330hp with many inexpensive bolt on performance upgrades. The engine is originally equipped with an intercooler which we include as a standard item in the conversion. The intercooler is a massive aluminum design with approximately the same thermal dissipation as the stock intercooler designed for the Cummins Engine.



Drive Train:

The remaining drive train can be fully reused which gives the end user the ability to simply purchase the Cummins Conversion without the expense of replacing the reliable stock transmission and transfer case. The advantage of the Predator Cummins Conversion is that you are not limited to simply an engine upgrade. At the time of the conversion, or in the future, you have the ability of upgrading the either the 4L80 4-Speed Transmission or the Allison 5-Speed or Allison 6-Speed Transmission. All three transmissions are available in the stock configuration or can be further “Bullet-Proofed” by upgrading to our HD Transmission package. The HD transmission upgrade allows the transmission to handle up to 1000hp. The stock transfer-case is regarded as a very strong and reliable T-Case however we also offer a Predator 2wd upgrade to this transfer case. The new Predator 2wd Transfer-Case increases the vehicles ability by adding a 2wd mode to the drive train. The 2wd selection is very useful for increasing range by increasing fuel economy by up to 30%.



Transparent Technology:

The Predator Cummins Conversion includes all factory data reading, info logs, check engine lights and DTC (diagnostic trouble codes) through the OBDII Data Port. This ensures full transparence through all of the functions of the engine which aids in trouble shooting if the need arises. Additionally this “Transparent Technology” allows virtually any competent technician to diagnose repair and service your vehicle.



Performance:

12-Valve Stock- 220hp

24-Valve Stock-

24-Valve Common Rail Stock-

Fuel Economy increase, on average, of 38%.



Reliability:

With the reliability of the Cummins engine, it is a clear choice as a replacement engine to the GM 6.2L/6.5L series of engines. The conversion price is comparable to the price of a replacement 6.2L, 6.5L or 6.5Turbo engine which after converted will increase the reliability, performance, range and fuel economy. With a typical service life of over 500,000 miles before rebuilding, compared to the 6.5T service life of less then 100,000 miles which typically results in a non repairable replacement, the Cummins is a clear leader.



Options:

High Flow Reusable Air Filter

85hp Injectors

120hp Injectors

240hp Injectors

145hp RapTorq Computer Upgrade

42mm Turbo

Twin Turbo Kit

HD Stage 1 Transmission upgrade (up to 600hp)

HD Stage 2 Transmission upgrade (up to 1000hp)

2wd Transfer Case

Bio-Diesel Fuel Line Kit

High Flow Fuel Pump

Duel Fueler CP3 Pump

½” Fuel Line Kit (stock is 3/8”)

½” Fuel Line Kit Bio Diesel (stock is 3/8”)

12,100lb Half Shaft Kit

 

I'd love to see one of these claims of fuel economy increase in action... I get the same 10mpgs I got with the n/a 6.2. Then again, I don't think many of those conversions roll out with 44" boggers...

 

mine is at predator getting the 24v cummins put in.... here is a pic