diesel swap
 

I have a 83 GMC van with a inline 250 .
What are the options for swapping a small inline 6 diesel?
I once saw a 1960-70's ford half ton with a inline 6 diesel and it was impressive . Prolly a Cummins. :)

Re: diesel swap
 

The problem you are going to run into in a half ton truck is weight. A diesel six cylinder, even a small one, is much heavier than a v-8 which in it self is heavier than a 250 inline. Also frame twist is going to be a problem because the torque in a diesel is higher. so if you can address those issues then your golden. A 4 cylinder cummins would be an easer swap in my opinion.
Ken

Re: diesel swap
 

I don't know of any "small" 6 cylinder diesels :lol: physically they are all pretty big. But you can stick a 12 valve Cummins in ANYTHING...

Re: diesel swap
 

a 4BT is an exellent choice for a half ton truck, the only problem is that more people are realize'n this and the cost has really shot up for em.
theres alway's the 6.5 turbo, they can produce decent power and would be the easyest to swap into your truck.

Re: diesel swap
 

Well said. The only reason I'd go with a 6 cylinder diesel is to be different. A 6.2 or 6.5 swap would be the easiest, although the 4BT's are pretty neat and only weigh as much as a big block :lol:

Re: diesel swap
 

I have also been considering a diesel swap. I don't do any towing I really just want the fuel mileage. I know where I can get a 6.2 for a good price with hardly any miles on a rebuild. How hard would I be to swap into an 84 K10? I'm currently running a 350 crate engine with a 4L80E. I wasn't sure if my truck could handle the weight.

Re: diesel swap
 

I know that in the 80's you could get a 6.2 in a half ton from the factory. Not sure if they had some stronger springs in the front. A 6.2 will fit fine because it is a factory motor. You will basically need the entire underhood wiring harness for the 6.2. And I'm sure the fuel lines are different too.

Re: diesel swap
 

Would my truck really be that much slower if I did the swap? I am really only after the fuel milage but wouldn't want a slug. I runs great now but I only average 12-13mpg at best.

Also, what are good 350's selling for? It's a GM crate with around 30k on it with all new accessories.... Trying to decide if this would even be a smart financial move (I plan on keeping this truck a long long time)

Re: diesel swap
 

You could probably get about $1200 for that engine. If you're honestly getting 12 or 13 mpg from a 350, you're doing awesome. The diesel will be a dog compared to the 350 (if the diesel is stock), but it will be close to doubling the fuel mileage (20-22 mpg). If you're building for economy, the diesel is the way to go, but don't expect to get anywhere fast.

Re: diesel swap
 

you would have to keep the truck a long time to see any finacial gain after the money to do the swap, there's a lot of little crap that will have to be change'd.
the best thing would be to find a donor truck with a diesel so you have evry thing there.
I bought one of my son's a '84 K10, 6.2 4speed. it got close to 25 mpg. and I gave $2000.00 for the truck.
you wont smoke the tire's with a stock 6.2, but it will keep up with traffic fine.

Re: diesel swap
 

Sounds like I should stick with the 350, it runs great and the milage isn't too bad I guess. I just like diesels so I was curious.

Re: diesel swap
 

i am new to this diesel thing but I don't find the 6.2 too bad compared to my old 350 Burb its a little slower but a ton better on fuel. I wouldn't wish the 350 back myself.

Re: diesel swap
 

I definitely like the idea of diesel. I think if I found someone to buy my engine I would try the swap. If it was too slow I guess I could always turbo it!!

Re: diesel swap
 

I would imagine a turbo kit will just bring the fuel mileage down. It will make it faster (if it can handle it), but more air into the engine = more fuel into the engine.
Posted via Mobile Device

Re: diesel swap
 

Well if I saw it in a 70s Ford it wasnt stock.
The only small I6 diesel back then was a mitsubishi 6dr50a, which is rare.
Trouble with I6 diesel is the deck height because of long stroke.
Tough in a van. :)
ps the cummins fully dressed is 1000 pounds [internet]

Re: diesel swap
 

Yeah the deck height would surely cause problems in the van. Even the 4BT wouldnt help because its the same as the 6 cylinder cummins, just has 2 cylinders cut off.

Re: diesel swap
 

With a set of headers and free flow exhaust on a 6.2L, it won't be slow.

Re: diesel swap
 

You got it backwards... turbo's HELP diesels burn their fuel better. Better fuel burn = better fuel mileage. There are things to watch out for and more things to keep track of, but every 6.2 would benefit from having a turbo. You just can't go crazy with it and stomp on the throttle every time you want to get somewhere.

Re: diesel swap
 

The biggest issue I see with adding a turbo on a 6.2L diesel is engine longevity. The bottom ends are just are not strong enough to support that much power. These engines were designed to get excellent fuel economy in a 1/2 ton truck and they did very well at that.

Re: diesel swap
 

Actually, fuel lines are the same for the mechanical pump. Depending on your fuel filter setup on the 6.2, you may not have to change anything (I didn't when I went from 6.2 to 350 in my 87, currently going back to 6.2).

Wiring is the same for starter, alternator, and you could probly make the oil and temp gages work with the gassers wiring. All a 6.2 needs to run (besides glow plugs) is one key on 12V wire to the injection pump. Glow plugs are easy enough to wire yourself, by using a pre-85 relay and manual pushbutton.

Re: diesel swap
 

You can get a stud kit to really help strengthen them up. I think ARP sells a kit for the main girdle on a 6.2...

Re: diesel swap
 

Leave the gasser in it, loosen the rocker nuts and put some Limburger cheese on the exhaust manifolds.
That way it'll rattle and stink like a diesel with none of the headaches of the swap!

Re: diesel swap
 

Both of those items are band-aids and not fixes to a weak bottom end design. They may work but I still would not trust it to hold long term on a high performance turbo 6.2L. Remember, the original red 1982 6.2 block which also is one of the strongest out there due to the high nickel content was only rated for 130 hp / 240 ft-lbs torque. It did not make much power but it got very good fuel economy and they lasted forever if maintained. Over the years, power increased and fuel economy and longevity nose dived. I've got a 1982 6.2L Suburban with nearly 500k miles on the original engine and if driven conservatively, it'll manage 30 mpg. Stock form, it was extremely slow so I installed headers and a free flow exhaust. The difference was like night and day and I gained a little on fuel economy as well. It has plenty of performance to maintain all the speeds on the highway including the 80 mph speed limits in Texas. I also tow a 26' Airstream behind it. It doesn't keep up with the big boys but it does get the job done.

Re: diesel swap
 

Maybe this is suitable: Cummins/Onan 6AT3.4

"I believe that most if not all of them that came out of a bread van have the SM465 transmission so if you got a Chevy bell housing I think you would be okay. "

http://www.4btswaps.com/forum/showth...-6at3.4-nv4500

Re: diesel swap
 

What headers would you suggest? I'm only seeing the Hummer headers and they're a bit pricey.