classic Airstream fuel conversion gas x diesel

[Luiz]

Hello friends,
Please do anyone has an idea of the total cost of a perfect job of conversion of a gas engine + transm to a diesel one. I am searching for a classic AS diesel to import from Brazil but i can not find a diesel one, so i am thinking on buy a gas one and make the conversion.
Please let me know your opinion.
*forgive my english errors ok!

[Smartstream]

Originally Posted by Luiz

Hello friends,
Please do anyone has an idea of the total cost of a perfect job of conversion of a gas engine + transm to a diesel one. I am searching for a classic AS diesel to import from Brazil but i can not find a diesel one, so i am thinking on buy a gas one and make the conversion.
Please let me know your opinion.
*forgive my english errors ok!

The cost of the conversion will likely be more than the cost of the motorhome. If you do it yourself or with the help of friends it will have to be a labor of love. It is not an impossible job but it does require many hours of labor and paid labor is not inexpensive.

[Mike Leary]

The transmission was re-programmed to take the diesel, so a standard 370 turbo (as supplied with the 454 gas engine) would not work. The only options I could think of if the crappy 454 was toast would be (A) replace the 454 with a modern crate engine with newer, improved, exhaust manifolds.(B) One of our forum members replaced his gas engine with a diesel Chev Duramax/Allison combo, but he never told us what it cost.

[blkmagikca]

The diesel motor-homes have a heavier chassis than the gas ones. Diesels, as you know, produce much more torque, and the transmissions have to be more robust.

My suggestion is to not buy a gas moho, but keep looking for a diesel one. Keep in mind that the gear ratios are different - I had a '94 LY and the 230-hp Cummins redlined at 2,500 rpm - a gas engine would likely redline at close to 5,000.

[Smartstream]

Originally Posted by blkmagikca

The diesel motor-homes have a heavier chassis than the gas ones. Diesels, as you know, produce much more torque, and the transmissions have to be more robust.

My suggestion is to not buy a gas moho, but keep looking for a diesel one. Keep in mind that the gear ratios are different - I had a '94 LY and the 230-hp Cummins redlined at 2,500 rpm - a gas engine would likely redline at close to 5,000.

The Classic mohos were built on a P-30 Chevy chassis with a 454/TH400 or TH475 in the chassis. Airstream removed the 454 and installed the Isuzu diesel. The modifications to the transmission were primarily to the valve body and relatively minor. The Isuzu is governed at 3300 rpm and had a max speed of 65-67 mph with the 4.56 gear in the differential. The 32.5 and 34.5 added a tag axle to carry the extra weight.

[Luiz]

Mike, Dan, everyone...
Thanks for the information, i did not know that the chassis was different. I will keep searching wait for the original diesel one.
Thanks again.
Luiz

[wxbuoy]

Originally Posted by Smartstream

The Classic mohos were built on a P-30 Chevy chassis with a 454/TH400 or TH475 in the chassis. Airstream removed the 454 and installed the Isuzu diesel. The modifications to the transmission were primarily to the valve body and relatively minor. The Isuzu is governed at 3300 rpm and had a max speed of 65-67 mph with the 4.56 gear in the differential. The 32.5 and 34.5 added a tag axle to carry the extra weight.

There are also a few late model classics that came with the cummins 6.9BTA and Allison transmission in the front engine configuration. But the rear pusher is far more common diesel. We spent allot of time on the different sites looking for one. A used cummins in good condition will run you $4500 and up to $9000 a new in the box go from $9500 and up. We were strictly looking at what ifs when we bought ours and figured it would be between $20,000 and $25,000 to replace engine and transmission in the event of a catastrophic failure. So if you get a diesel motor home the engine and transmission will be worth more than what you are paying for it!

[blkmagikca]

One of the members of my unit has a 1995 Classic diesel pusher - built on a Spartan Chassis with a 5.9 litre Cummins engine and 6-speed Allison transmission. It is the same running gear as I had on my '94 LY moho which I sold in September 2011. Here is what mine looked like: 1994 Airstream Land Yacht Class A Diesel Pusher

[ViewRVs]

Luiz,

My Airstream motorhomes page will show you all of the different makes and models. I suggest finding the model you like and searching for that. I agree that a conversion is not feasible.

If you are importing to Brazil, is an LP gas conversion an option? I know my old gas 345 was exported to the UK and converted to LP.

[cooperhawk]

Originally Posted by Smartstream

The Classic mohos were built on a P-30 Chevy chassis with a 454/TH400 or TH475 in the chassis. Airstream removed the 454 and installed the Isuzu diesel. The modifications to the transmission were primarily to the valve body and relatively minor. The Isuzu is governed at 3300 rpm and had a max speed of 65-67 mph with the 4.56 gear in the differential. The 32.5 and 34.5 added a tag axle to carry the extra weight.

Actually the transmission was replaced with an Allison 4-speed.

It is my understanding that the P-30 chassis were shipped to Isuzu and the engines installed prior to building the body. In fact I have seen photos of flat cars loaded with these very frames.

In 1985 and later the 6bd1s were installed with factory super chargers and many improvements in the engine.

[cooperhawk]

In late 1984 and early 1985 Airstream started installing the improved 6bd1. The new engine has cylinder oiling, heavier crank, stronger connecting rods and stronger pistons. In addition the cylinder head has better valves.

This engine was equipped with the factory turbo as well.

It has 30 more horsepower than earlier models..

This information came directly from Isuzu's Industrial Division.

[Luiz]

Thanks again for the informations.


Yes a lp conversion is legal but i do not like it, i had a dodge dakota converted and it was very "weak".
Unfortunately the law of Brazil does not allow to import used vehicles unless they are 30 years old or more, collectible vehicles.
Luiz