Community Forums

Ed Anderson · 10-22-2013, 05:53 PM

I am trying to replace my 454 Gas engine 1987 Itaska sunflyer with a Duramax diesel with Allison Transmision. Is there a Kit for this?

Fl_Richard · 10-28-2013, 04:54 PM

Yes! Your custom welder has all the parts

Seriously I doubt it. You'd have to give more details.

Argosy · 10-28-2013, 05:03 PM

The best kit would be a wrecked vehicle of similar size, you're going to need a lot of major parts from the engine to rear axle, and smaller ones like wire harnesses and computers.

caissiel · 10-28-2013, 06:35 PM

6.5l diesel is a pertect fit. But still need the whole truck.
There are many Cummings diesel swope kits available. The 5.9l has been put in all kinds of truck.
I believe the duramax is very similar in size to the large block GM but the transmission will be a bit higher. But might just fit properly in a mh.

GraySeal65 · 10-28-2013, 06:43 PM

Quote:

Originally Posted by Ed Anderson

I am trying to replace my 454 Gas engine 1987 Itaska sunflyer with a Duramax diesel with Allison Transmision. Is there a Kit for this?

Put another 454 in it and trade it for a diesel pusher. If I have learned anything from custom cars it's that when you have modified anything it becomes very unreliable.

450Donn · 10-28-2013, 06:47 PM

There is a fella in TX someplace that converts Suburban 1500's to Duramax/Allison. It is expensive to do right. You definitely will need a donor vehicle of the same year and model as you will have to swap out the computer, fuel tank, fuel lines engine, wiring harness, transmission, TCM,ECM and probably a whole lot more. It can be done, but not by a back yard mechanic. It is far more complicated and expensive than in the old days.

FIRE UP · 10-28-2013, 10:32 PM

Quote:

Originally Posted by Ed Anderson

I am trying to replace my 454 Gas engine 1987 Itaska sunflyer with a Duramax diesel with Allison Transmision. Is there a Kit for this?

Ed,
Not sure of your capabilities, experience or tools available including lifts, transmission jacks and a whole lot more but, if you've got any "back yard" mechanics in you, this could be a fun job. Many wouldn't attempt it and would advise against it but, it's still just an engine swap. Yes, a bit more complicated than "yester year" engine swaps (done a few) with a carburetor and the ability to put any transmission you want behind your new engine. It would be nice to acquire the entire donor truck/vehicle so you can get a complete wiring harness, and any all particulars etc.

There are also business's like "Painless" wiring that build complete engine wiring harness's for a zillion applications. Not sure of the weight differences between the two engines but, that may be a consideration too. If the Diesel block which, normally is constructed to seriously stronger standards is that much heavier, something might be needed to compensate in the suspension area too, not sure.

One more thing, in todays world, not sure about your local but, especially in CAL, smog rules have tendency to put the "kibosh" on a lot of potential engine swapping that used to be legit and legal. Anyway, if you've got the drive, a place to do the work, the background for the technical side and, the tools, (more than likely some welding for motor mounts etc. will be necessary) , I'd go for it. Obviously you've taken into account the value of the coach VS the amount of dollars that will be needed to make a complete, running swap. Good luck if you try.
Scott

Cat320 · 10-29-2013, 09:45 AM

Quote:

Originally Posted by 92TNTRacing

Put another 454 in it and trade it for a diesel pusher. If I have learned anything from custom cars it's that when you have modified anything it becomes very unreliable.

That's what I'd do. Get rid of the present RV (trade/sell) and buy a DP.

R2Home · 10-29-2013, 09:53 AM

How deep are your pockets? Not only will the items that have already been mentioned need to be changed out, but also the cooling system, exhaust system, fuel system and I am sure that there are many other items.
Unless you are really 'attached' to this unit, replace the gas engine and get a good used MH with a diesel engine.

Tony H · 10-29-2013, 10:03 AM

Another option would be to put a Chev 502 HT crate engine in. The HT is designed as a high torque engine as opposed to the other high performance 502 crate engines and is essentially a bolt in. The difference towing is like night and day. I've long thought it would make a great motorhome engine.

I replaced the 454 in my '87 3/4T Suburban in 2000. The Suburban was used primarily for towing an 8,000# trailer until we bought a motorhome with a V-10 and we put 40,000 miles on it without a single problem.

PM or email me if you'd like more details about the swap.

1ciderdog · 10-29-2013, 11:06 AM

I kind of doubt that will improve resale value when if you chose to sell it. You must be planning on keeping it a long time. But if you want to do it then go for it.

akeyzoo · 10-29-2013, 03:13 PM

Quote:

Originally Posted by 92TNTRacing

Put another 454 in it and trade it for a diesel pusher. If I have learned anything from custom cars it's that when you have modified anything it becomes very unreliable.

I agree. This IMHO would be like opening pandora's box. Can you fit a large enough radiator/intercooler? Will the tunnel/hood support that larger block and have room for the turbo at the rear? Can you make the right fuel tank fit? Where I live this would not pass emissions as they would expect GAS.

Chris

George Schweikle · 10-29-2013, 03:26 PM

6.5 turbodiesel is not a Duramax. That is 6.6 and a completely different engine.

Quote:

Originally Posted by caissiel

6.5l diesel is a pertect fit. But still need the whole truck.
There are many Cummings diesel swope kits available. The 5.9l has been put in all kinds of truck.
I believe the duramax is very similar in size to the large block GM but the transmission will be a bit higher. But might just fit properly in a mh.