'93 classic 6bt/Allison 6speed conversion

[mtlagger]

Good afternoon everyone... I've been pondering installing a Cummins 12valve 6bt with the p pump with an Allison 6 speed automatic in my '93 classic mh. I've been looking through some of the posts and threads and there's been folks that have done this but I'm not sure if they are still active on here. I would appreciate any help....info....ideas anyone has on this.

Thanks
Marty

[Kota]

The 5.9 with the intercooler/radiator stack and the Allison is a huge hunk of metal. It would be a challenge and might require some work on the front suspension.

[mtlagger]

Kota,
I admit I've got a pretty good project on my hands. I've looked around on the web and have found loads of sites and folks that have made this conversion into the Chevy IFS P30/32 chassis and pickups.
There are motor mounts available the transmission mount I may have to make.

I need to mention that I have a complete donor rig....a '96 34 ft. Gulfstream with air over hydraulic brakes and it was a steal...plus I was able to drive in home. So I have everything that made it run and drive on hand.

From what I've read so far....the Cummins weighs in dry at right at a 1000# ....the 454 about 600/650# . The Allison is about 535 and I'm guessing the 4L80E is somewhere around 200/300#. I'm going camping this up coming weekend and on my way home I'm going to get the 36 weighed....front....whole....rear. I'm hoping this will give me an idea as to where to start when I re spring the front end. Once I have all the parts out I will weigh the motor and transmission as a unit (both power plants) and figure out the difference.There are quite a few good options for larger capacity coils for the front....along with some new airbags I should be able to take care of the additional weight.

Of course the generator is gas and it runs like a champ....so it's staying. I'll add an additional tank and fuel fill for that.
The thing that concerns me the most is the motor box. If I need to or have to modify it to much the whole thing may come to a stop.
It's a good thing I still have the 32 excella to camp in.

Marty

[bkahler]

Marty, here's a couple of threads that might give you some ideas.

454-to-cummins

cummins-diesel-upgrade-to-classic-mh

Brad

[Isuzusweet]

I don't know if the front spring rating is different between 454 and Isuzu diesel versions. If not, then the front suspension should be fine as the Isuzu is a 1100 lb beast of a motor.

Cheers
Tony

[mtlagger]

Brad,
Thanks for sending me those links. I had stumbled across them this past week and haven't been able to find them again. Now here's the big question.....is the originator (Wayne) still active in the fourms? I sure would like to pick his brain on the install. I have no doubt I can get the Cummins shoehorned in there, but the extra knowledge would be great.
I'll let everyone in on what I've got in this so far....the donor unit is 34ft. long.....I've got less than 3 bucks a foot in it. According to my Cummins buddies the 6bt and 6 speed Allison are like the holy grail of finds.


Tony,
I've only read about the Isuzu MH's. I've not seen one....but you've given me something to look into as far as suspension similarities go. All the extra help is greatly appreciated.
Thank you so much.


Thanks so much everyone
Keep the ideas coming
Marty

[Kota]

Having the donor vehicle is a big help. I've done several drivetrain swaps putting modern drive trains in classic vehicles. Anything is possible. Maybe not practical, but possible. Never let the couch tatters tell you that it's impossible.

I built this shop to work on "impossible" projects.

Good luck and keep us informed.

P.s. I'd go all the way an put it in the rear!

[bkahler]

Originally Posted by mtlagger

Brad,
Thanks for sending me those links. I had stumbled across them this past week and haven't been able to find them again. Now here's the big question.....is the originator (Wayne) still active in the fourms? I sure would like to pick his brain on the install. I have no doubt I can get the Cummins shoehorned in there, but the extra knowledge would be great.
I'll let everyone in on what I've got in this so far....the donor unit is 34ft. long.....I've got less than 3 bucks a foot in it. According to my Cummins buddies the 6bt and 6 speed Allison are like the holy grail of finds.

Marty, try contacting Wayne by sending him a PM. His last activity was back in 2009 so I'd say being able to contact him is iffy at best.

Brad

[Bill Lynch]

Can you put the Airstream body on the Gulfstream chassis?

[mtlagger]

Kota,
Nice shop!!! Mines not nearly that big or tall for that matter. I can get the coach inside out of the weather. I have given some thought to putting the engine in the rear, but with the tag axle and the water tank under the bed I'm thinking the engineering would be more than I'm will to tackle. The Mrs. and I like traveling in it to much to keep it laid up for to to long. Plus I'm sure there are body parts that I wouldn't be able to get my hands on easily.

Brad,
I sent a message to Wayne Olson I'm hoping he responds....but who knows. Even if he bought his rig with the conversion done I'm sure he has some good pointers.

I've got some pretty talented folks I work with along with a machine shop so I hope that once I start this it will go smoothly.


Bill,
I hadn't given any thought to swapping coach bodies. I'm 2 feet longer and have the tag axle opening to deal with. Again I think I'd be dealing with body sheetmetal that may not be available.
I'm still going to look at it tho.


Thanks again everyone.
What's great... is the ideas and the different ways everyone looks at this.

Marty

[Kota]

Just a couple wild thoughts. That donor would have everything you need for the rear engine swap. Bet it's got fuel, water, and waste tanks mounted between the frame rails like the 360 pushers. If the frame rails are the same distance apart it might not be as bad as you think. There's not much built into those bodies to make them specific. Only stuff cut out and built back up. Meaning removable. Pretty much just a shell. That Eaton rear axel and suspension could replace the rear axel set. Filling in and moving the wheel wells would be more than doable. Nothing complicated about them.

Before I found the pusher I had the same perverted thoughts of mating a low mileage rotted roof drivable Alegro with a local 345LE that had been sitting in an open hay barn for 20 years.

[mtlagger]

The Gulfstream is on a Spartan chassis.... isn't that what Airstream used on their pushers?

[OTRA15]

Originally Posted by mtlagger

The Gulfstream is on a Spartan chassis.... isn't that what Airstream used on their pushers?

A couple of general suggestions FWIW . . .

In addition to the Private Message system here, you can also Quote the posters on earlier threads to get their attention, assuming they have toggled on notifications in their User CP.

Also, for finding threads you have read and want to go back to, you can Bookmark them, or save as Favorites, depending on which browser you are using. With so much information here, keeping track of where you have been is absolutely necessary.

Good luck!

PS Marty, welcome to the forum!

Peter

[mtlagger]

And just when I thought swapping engines or the bodies was going to be the tuff est thing to do.....
This group of posts is the most I've ever done on here, and I've been a member forever.

[Kota]

Originally Posted by mtlagger

The Gulfstream is on a Spartan chassis.... isn't that what Airstream used on their pushers?

It's on an Spartan EC2000. If the frame rails are similar in size and spacing all the mounts may be usable to stick the drivetrain in the rear.