6.5 Turbo reliability for an RV?

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mcarlo86

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I think the main reason I started this thread was to explore ideas about swaps, pros vs. cons, in an RV. I understand that it never would be economic to do a swap, (as a Cummins swap in a square body pickup probably is rarely an economic swap either) but thought it could be an interesting project. I look at this RV as a fun vehicle just like I do my '68 C10 and my '90 Suburban. I do think a cooling system upgrade is what I will be doing for sure in the short term. I enjoy the discussion and wealth of knowledge in this forum. Great bunch of people who share common interests in vehicles!
 

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That’s exactly what I’d do. Keep the mechanical fan and add an aux. electric also. Doesn’t have to be fancy, even just toggle operated. You might try inspecting the radiator, and if it’s scaled up, have it cored and serviced. Otherwise you might see about having a new one made with someone like Champion, Fontana Radiator Works, or U.S. Radiator.
 

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I think the main reason I started this thread was to explore ideas about swaps, pros vs. cons, in an RV. I understand that it never would be economic to do a swap, (as a Cummins swap in a square body pickup probably is rarely an economic swap either) but thought it could be an interesting project. I look at this RV as a fun vehicle just like I do my '68 C10 and my '90 Suburban. I do think a cooling system upgrade is what I will be doing for sure in the short term. I enjoy the discussion and wealth of knowledge in this forum. Great bunch of people who share common interests in vehicles!
Brush Truck Repair over here, He took a SB CCLB Dually and installed a cummins into it, easy swap according to him, but, he has been doing this stuff for most all His life, mainly on the big rigs and if someone would like a diesel conversion He will put that together for them too.
If I were going to do a different engine into My 2000 K3500, 6.5, I`d be out there talking to Him first. When I first got the pickup truck, he said he could fix that 6.5 with a Cummins but the body would neeed to be lifted three inches. LOL
 

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For any swap it is almost always cheaper and better to get a donor vehicle. If you really want to think about a diesel, I've seen some buses with the 5.9 cummins or Cat C7's in them for $3,000 or less... running and driving. We had Cat C7 ASERTs and Allison 6-speed automatics in the mine resistant vehicles and at 30,000 lbs they would pull down 20-24 mpg using military grade diesel.
 

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Also, another GMT 400 K2500 suburban just popped up for sale in my town. Running, driving, and he's asking $800. So you could probably easily talk him down to $500. L-29 454/4L80E/NP241 drivetrain with a 4.10 geared 14B FF. I've seen the guy selling it trying to buy catalytic converters, so I'm sure he bought it for cheap, cut the cats out and sold them, and is now trying to get rid of the rest of the truck.
 

mcarlo86

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Also, another GMT 400 K2500 suburban just popped up for sale in my town. Running, driving, and he's asking $800. So you could probably easily talk him down to $500. L-29 454/4L80E/NP241 drivetrain with a 4.10 geared 14B FF. I've seen the guy selling it trying to buy catalytic converters, so I'm sure he bought it for cheap, cut the cats out and sold them, and is now trying to get rid of the rest of the truck.

That would be a great engine/transmission swap idea for my '90 burb! ;)

I read on another forum that a guy who had an older Winnebago on a Dodge chassis bought a 90's Ford ambulance for cheap and swapped the 7.3/A4OD into his motorhome. I have thought about the bus idea before too. Would be an economic option for getting a Cummins.
 

mcarlo86

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Brush Truck Repair over here, He took a SB CCLB Dually and installed a cummins into it, easy swap according to him, but, he has been doing this stuff for most all His life, mainly on the big rigs and if someone would like a diesel conversion He will put that together for them too.
If I were going to do a different engine into My 2000 K3500, 6.5, I`d be out there talking to Him first. When I first got the pickup truck, he said he could fix that 6.5 with a Cummins but the body would neeed to be lifted three inches. LOL

Where is Brush Truck Repair located over there?
 

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How is a 40 year old RV any different than a 40 year old pickup? Are you saying we shouldn't put any effort into our old trucks to make them better or try different things? Most people with old iron aren't content with just "keeping it on the road" and there's nothing wrong with that. I'm sure Brian has the RV because he likes it, rather than because it was cheaper than a new one.

Fair enough. I suppose I was presumptuous, as when I think 40 yer old motor home, I think homeless camp, not resto-mod.

That said, a 6.5 is still close to the bottom of the list of engines I would consider an "improvement". But if a guy is up for a challenge and has money to spend, that engine checks both of those boxes...in ink!
 

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To address your actual question with my unimportant opinion,

Seems like, while a 6.5 is a noisey thing, you could have yourself a little more low end torque and pulling power, and obviously... The diesels like heat, you'd just need watch your temp gauge for the trans. If you're going with a 6.5, probably be best to run a 4L80e Behind it too, but as I understand it, swapping in a 4L80E will require some floor pan work (I could be wrong).


If you'd be willing to put that 4l80e in, you might Would consider a little stouter motor like a 8.1L, but I don't think you're really gonna see impressive MPG.
They're known for their grunt, not the smiles per gallon.


I reckon you could add some electric fans, oil, and trans cooler if you don't already have it, it'll take away some of the heat from your current motor. I feel confident of that much.
 

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As long as we're speculating, let's go for broke. 6.6L Duramax with an Allison. That will climb hills, no problem.
 

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As long as we're speculating, let's go for broke. 6.6L Duramax with an Allison. That will climb hills, no problem.


Deep inside, I thought to myself, if we're willing to go Cummins with a custom adapted th400 with gear venders OD... Or retro fitting a 6.5

Why not dirtymax?!?
 

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To address your actual question with my unimportant opinion,

Seems like, while a 6.5 is a noisey thing, you could have yourself a little more low end torque and pulling power, and obviously... The diesels like heat, you'd just need watch your temp gauge for the trans. If you're going with a 6.5, probably be best to run a 4L80e Behind it too, but as I understand it, swapping in a 4L80E will require some floor pan work (I could be wrong).


If you'd be willing to put that 4l80e in, you might Would consider a little stouter motor like a 8.1L, but I don't think you're really gonna see impressive MPG.
They're known for their grunt, not the smiles per gallon.


I reckon you could add some electric fans, oil, and trans cooler if you don't already have it, it'll take away some of the heat from your current motor. I feel confident of that much.

It does have a hefty trans cooler already. I do think electric fans in addition to the big clutch fan and an engine oil cooler would probably help a lot. An 8.1 would be a cool swap too. Having modern fuel injection and a 4L80E would be sweet.

Realistically, warming up the 454 (heads, headers, flat top pistons), cooling upgrades and a 4L80E would probably be most cost effective and would be a lot of fun too.
 

mcarlo86

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As long as we're speculating, let's go for broke. 6.6L Duramax with an Allison. That will climb hills, no problem.

I will start saving my money. Maybe it will be a retirement project for me in 20 years. :rockit:
 

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My opinion is to fix the cooling system, and if/when the trans goes, install a 4L80 and maybe deeper gears. The engine is already there, runs well, only runs warm. Your probably going to need cooling system upgrades with whatever engine you swap in, might as well address the cooling system with what you already have. Deeper gears combined with overdrive and a locking converter will ease the load on the engine, make cruising more comfortable without the engine screaming, and might improve mileage.


Before spending a dime, you might want to install a temp gauge, just to verify you actually have a issue. No point chasing a cooling system problem that isn’t really there.
 

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