I have a 2000 H1 and have just begun a Alpha/Duramax cooling system conversion (shaft drive fan)....Anyone have any experience with this? Even AMG didnt seem to have any answers. They used to be a lot of help with off the wall questions, but now some jerk answers the phone in the tech department and you cant get past him.
With the Duramax conversions out there, I was amazed to find out that no one updates the cooling systems! A firend of mine has a Duramaxed 2002, and its virtually unuseable because of the heat it generates. I've built 6.5TD's that I'll pull on a Duramax all day long, so I decided to stick with it. I'm also not a big fan of body lift kits (2006 Alpha).
The shaft drive fan system is an awsome system, and Hall H1 racing has used it in the Baja, and say that its hard to get the temp past 200. I pull a 15,000lb 40ft race boat, and with this mod, the H1 should work fine. the parts for the conversion are not cheap especially since I didnt have a core to trade in. total cost so far is about $3500. from what I can tell, the Duramax sits to the right of center just like the 6.5TD. The only difference is, since the Duramax is more modular, when its placed offcenter, it needs to be two inches higher, hence the body lift on the new Alphas. If anyone is intersted in this conversion, let me know. I'd be happy to follow up with the problems I may incur. All in all, I'm starting on it this Friday 10/6 and should have it finished in a week or so.

 

I am interested in your conversion just because it sounds interesting and challenging. I find it interesting that the engine needs to sit highr when offset. That would be one of those things you would never think about until you are knee deep in parts and wondering what to do next. I am also curious about the shaft drive fan. Is that driven by a shaft coming from some accessory drive belt on the engine, or is it mounted directly to the crank shaft or what? Sounds interesting, and as you go along with this, if you post it, I know I will read what you write with facination of your project.

 

The shaft drive system is directly attached to the crankshaft. Its then routed to a gearbox that the fan is attached to, which puts the fan directly under the radiator. The fan drive gearbox is awesome how it works. It directs power up, to the side, and at an angle. I can now understand why it took AMG soo many years to come up with it. I think the majority of people think that the new Alpha is a better truck because of the Duramax, when in fact its the cooling system. Cant have more power without better cooling. The Duramax in the Alpha needs to sit 2 inches higher because of the block size and/or exhaust setup. The H1 is quite strange in the fact that the engine/drivetrain sits several inches towards the passenger side. Thats part of the reason why AMG had a hard time with the cooling. Making more power is easy, but getting the heat out is hard. I have tried everything in the past with H1's I've owned, but absolutely nothing works. The electric fans help a little, but its still impossible to use as a tow vehicle. I'll try to get some pictures in the next few days.

 

I am interested in your conversion as well... I have always wanted to drop the duramax block in my H1 ever since I got it but never knew anyone that has had it done so didnt know there were problems but now you opened my eyes and I am really wondering if the duramax is the way to go for me...

Thanks alot! and hope to hear updates!

 

I am familiar with the HMMWV from my time in the Marien Corps. I drove them and worked on them in a limited capacity, so I am aware of the original configuration. Now that you have pointed out the differences between an Alpha and a H1, I am very curious to see under the hood of an Alpha.

 

Followup: I'm buying another digital camera on Ebay so I should be able to get some pictures of the conversion soon. From what I can tell at this point, there are two areas that will be a small problem. First, since the Duramax sits in the frame two inches higher, the fan drive assembly needs to be installed two inches lower for the 6.5TD. Other than that, the crankshaft centerline should be in the same location. Second, since the fan drive assembly needs to be mounted two inches lower, I would need to either lower the fan shroud (spacers) or lower the entire cooling assembly. Can't raise the fan with a spacer because the fan is mounted to the drive assembly at an angle. A fan spacer would put the fan in the wrong location. Just keepin' ya other H1'rs posted.....