Duramax/non-Allison transmission possibilities

[convert2diesel]

Been doing some backyard design work on my new Cadillac diesel conversion. Everything up to now has been on paper but have been exploring some possibilities.

What keeps coming up is trying to stuff a Duramax into the car. From a power point of view it is the hands down winner and as this will be used to tow my trailer, that is a definitive plus. The level of computer control is both a blessing and a curse as I will be using this as my daily driver.

My problem is with the Allison. Not that it's not a good tranny but that likely it is overkill. Trying to justify shoehorning that brute into the car is a stretch. Would require major sheet metal work and would be a clearance night mare, not to mention the driveshaft would only be about 2 feet long.

I guess my question is, is there any other trannies that will bolt up to the Duramax or are there adapters available? I have done some measurements and am pretty sure I can get the engine to fit without too much carnage but the Alison is another story.

This is more a "what if" discussion as opposed to a spec comparison. For instance, a built 400 and a gear vendors would give me enough gears and the 400 could certainly be built to stand up behind the Duramax but I have no idea if it could be married to a Duramax.

Looking for an education here as up to now, my conversions were based around the 6.2/6.5. Any info would be appreciated.

Bill

[More Power]

The Duramax 6600 has the very same bellhousing bolt pattern as the Chevy/GMC TH400 and 4L80-E. In fact, GM is currently using the Duramax/4L80-E in their vans. The engine is derated to 250 hp & 440 lb-ft torque - to work with the 4L80-E's input torque rating.

Not only is the bellhousing bolt pattern the same, but the torque converter bolt pattern is as well.... ;)

I have a photo of the Duramax 6600 bolted up to a TH400. I used that configuration for the initial fit measurements for our Lil Red conversion project.

Jim

[convert2diesel]

That opens up a number of interesting possibilities. Really only need 250 HP for what I am doing and that would open the door for some creative tuning to get the mileage up. Haven't bothered to check into a typical fuel map for this engine but have the software (and I hope the GM passwords) to allow some tweaking.

Would prefer not to have a computer running my engine but removing it would not be an option on the Duramax (unless someone has figured out how to drive a common rail mechanically :eek:)

Is there better or worse variants of this engine? The variable geometry turbo intrigues me but does it come with it's own special problems?

Not trying to pull stumps with this arrangement and car and trailer together wiegh less then 10,000 lbs. It is after all, my daily driver and it would only tow about 4,000 miles a year. Was able to tow the new trailer home about 200 miles with the 6.2na but the poor little thing was running flat out on basically a level surface. No way it would handle the hills, ergo the new to me Burby. The 5.7 gasser handled the power requirements well on our yearly trip south, so all I have to do is duplicate the power curve using a real engine. Even with the 6.2 running flat on the floor, it still got 50% better mileage then the Burby doing the same job.

Anyways you got me thinking.

Bill