Hummer H1 The original Hummer, which brought the Hummer look to the public eye during Desert Storm, with the addition of some features that make the H1 more of a street vehicle and less of a Army truck

Cummins conversion for H1

Old 03-31-2008, 07:40 PM
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Join Date: Dec 2007
Posts: 59
Default Cummins conversion for H1

Does anybody specialize in this?
Old 03-31-2008, 08:28 PM
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Default RE: Cummins conversion for H1

I'm not sure anyone specializes in the Cummins conversion. I know a few guys have done it. Injun has looked into and knows more about the Cummins conversion than I do. He will post shortly I am sure.
Old 03-31-2008, 11:25 PM
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Default RE: Cummins conversion for H1

Avalanche Engineering( has done a couple Cummins conversions but they pricey around $29k USD for the base conversion which includes used mechanical 6bt engine, rebuilt transmission with upgraded clutchs/torque conversion,body liftand the labour... tcase remains stock. They also do common rail which is a bit more(not to sure how much).
Also painless performance makes a harness for the cummins which basically will make the hardest part of the conversion(wiring) painless.. basically hook up the harness... plug it into the battery and ignition and boom your cummins is rdy to run in any vehicle.... There also is a local place that does conversions charged a friend $10k CDN for a rebuilt 4bt mechanical cummins and labour to put it into his Jeep TJ... which isnt bad... I think ima go with them and supply the parts myself so it is done right.
Painless Harness... Atlas 4speed T Case.... thinking about new 6 speed version of our transmissions 6L80 although there is problems with getting it to work currently due to no aftermarket standalone computer for it but im sure that will change... Also want to replace my halfshafts and hubs with some 12k ones... a few other things as well but yea should be pricey but by supplying it all myself i can slowly pay for it by buying items here and there so it isnt one big lump sum.
Old 12-16-2009, 04:00 PM
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Join Date: Nov 2009
Posts: 9

predator motor sport in the San Diego area can do a hummer h1 6bt conversion for $14999!
Old 12-16-2009, 05:05 PM
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Join Date: Feb 2008
Posts: 54

I would be really curious what a $15k 6bt conversion would look like - Alot of the work is modifications to the truck just to make room for the engine, which has massive length and height compared to any of the v8 diesels they put in the H1's factory. I could see maybe 15k in labor alone, but... like anything, I guess if they are able to streamline the install it gets cheaper. I did my conversion with some help over about a 4 month period, which was more time intensive as it went on - If I'd been at it 40-50 hrs a week, it probably still would have taken close to two months.
Old 12-17-2009, 02:29 AM
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Join Date: Nov 2009
Posts: 9

They have a few videos on YouTube that show a 24v and a 12v ready installed. Contact the sales department-that where I got the price from-"6bt conversion starts turn key installed at $14995"
Old 12-21-2009, 07:51 AM
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Join Date: Oct 2009
Location: West Michigan
Posts: 12

We have a considerable amount of experience with the H1 modifications for the 6.5L diesel. Give us a call and ask for Matt. He'll be happy to talk to you about the necessary modifications, not for a Cummins, but for the 6.5L.
Old 12-26-2009, 11:54 AM
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Join Date: Nov 2009
Posts: 9
Default Predator Motorsport Cummins conversion

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


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.


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.


12-Valve Stock- 220hp

24-Valve Stock-

24-Valve Common Rail Stock-

Fuel Economy increase, on average, of 38%.


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.


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
Old 09-25-2016, 07:13 PM
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Join Date: Sep 2016
Posts: 2
Default Motor mounts

Will anyone sell just the motor mounts and exhaust for a 95 12v 6bt cummins? There is already a cummins in my 93 hummer, but the engine is centered in the chassis and I want to move it closers to the passenger side so I can lessen the front driveshaft angle.
Old 09-27-2016, 05:00 PM
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Join Date: Dec 2015
Location: The Great state of Texas near Austin
Posts: 188

Maybe my brother will reply here with some more detail but The short version is you dont just need the engine mounts. Big Dog Offroad has designed a bolt in do it yourself cummins /allison kit that has everything you will need except the engine and the allison trans. Contact Eric @ For more details.

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