gas to diesel conversion

[mmusmanno]

has anyone tried to convert their gasser into a diesel dog? i'm looking for info about it and/or a mechanic that is interested in doing the project. I have an '83 k10 shortbox with a 350 and want to put a 6.2 into it. anyone have any info/thoughts/etc, greatly appreciated.

[Jonboy]

No offense, but if you were going to go through all of the hassle to swap to a diesel, are you sure you would want it to be a 6.2? I think there are some folks over in the 67-72 area that have done a Cummins swap. That would be pretty awesome in your 83.

Oh yeah, welcome to the board. I am sure there a re a lot of guys that know quite a bit more about doing a diesel swap than I do. All of the 6.2's we had when I was younger were low on power and a PITA in the wintertime. They aren't really fond memories out in the blowing snow with a battery charger and a WD-40 can.

[DirtyLarry]

Can be done. Unless, you have a 350 with a rod hanging out and a 6.2 burning a hole in your pocket I would suggest looking for a 6.5L. Cummins are nice but $$$ and not a direct bolt in as a 6.2 and 6.5 would be. The 6.2 got a bad reputation long ago...some deserved but some not....

The later 6.5L diesels were not too bad until you get into the electronic injection pump era. If your lucky enought to find a AM General built 6.5L you are even much better off, although those are very rare (GM sold off production rights, tooling, etc to AM General in January 2001).

A couple years ago I yanked a 6.2L out of a late 80’s Suburban and dropped in a brand new AM General 6.5L with a Banks side turbo and late model accessories for a buddy that lives back in Michigan. We thought about using a center mount turbo but the exhaust pipe would not fit between the firewall and engine. Later on in the project, my buddy sent me out some fancy custom tuned injection pump to put on it….and I have to tell you, this Suburban honked pretty good amazingly enough. Between the ball bearing turbo, marine prepped 6.5L and the custom injection pump it pulled like an early Dirtymax. He flew out here to CO and drove it back to Detroit without a single problem and got decent fuel mileage headed home as well.

I was suprised I even got it running without his help being I don't know jack about diesels as I have never had a chance to mess with them. I’d take a 6.5L like this if someone would give it to me. I am a big block guy and I was impressed by the way it ran.

[79GMC_OLDS]

i did


i wouldnt waste my time with a 6.2 or 6.5. a 4bt Cummins would work nice in your application. your stock drivetrain should handle the power easily. adaptors to bolt up to a chevy tranny are quite popular. check out 4btswaps.com they have lots of good info

[mmusmanno]

basically, I dig the truck, so, I want to do it right. i'm not married to a 6.2 or a 6.5, just thought it would be simplest. but, i'm all for a cummins. what would be the best engine/setup for performance? horsepower AND torque? my local mechanic will do the job but he wants me to get a donor vehicle. so, if you guys agree, what vehicle should I get, if not, then what do you think is the best way to get this new powerplant and get it in? thanks.

[79GMC_OLDS]

Originally Posted by mmusmanno

basically, I dig the truck, so, I want to do it right. i'm not married to a 6.2 or a 6.5, just thought it would be simplest. but, i'm all for a cummins. what would be the best engine/setup for performance? horsepower AND torque? my local mechanic will do the job but he wants me to get a donor vehicle. so, if you guys agree, what vehicle should I get, if not, then what do you think is the best way to get this new powerplant and get it in? thanks.

well a 5.9 cummins will give you the most hp and torque the easiest but it will destroy your stock running gear in a hurry. a 3.9 4bt you can get from a p30 stepvan. if you are running a th350 or 400 tranny then find a p30 with a 4bt/th400 combo and you will have the parts to bolt it up. you will need custom motor mounts and plumbing and wiring and exhaust etc. they come with 100-120 hp i believe but also have approx 300ft lbs just off idle. there are lots of things to do to increase power if needed. there are also a couple posts on ck5.com with some guys that have done it.

[old Rusty C10]

better check about passing emmissions first i know some states will not allow their computer to recognize the fact the truck is now a diesel after it came from the factory gas.. had that happen in NYC to a buddy he had to find a less reputable inspector to get a sticker

[Russell]

3.9L 4BT rattles and shakes a lot, and is very noisy, but will generate significantly more power than a 6.2L or 6.5L with relatively the same amount of work, and get 30 mpg to boot.

6.2L with a 6.5L turbo setup will net you with an engine that is very similar to a 6.5L. Many people, myself included, believe that a first year 6.2L (red block) is the strongest of the GM diesels due to a better block metallurgical makeup which is a bit stronger and transfer's heat a bit better.

Personally, I am building an 82 red block 6.2L with a set of 6.5L heads, and a GM3 turbo / injection pump and injectors from a 93 1 ton parts truck. I am expecting stock 6.5L performance from it, which is similar to a TBI 350. If I like the engine, I may eventually upgrade to a GM8 turbo, marine injectors and a marine injector pump.

If you do go with a GM diesel, make sure you brace the mains with a girdle, upgrade the cooling system to the newest 99 dual thermostat / high volume water pump setup, put in head studs to replace the torque to yield bolts, and replace your harmonic balancer, regardless of if it looks ok or not.

[mmusmanno]

this is great stuff guys, thanks, keep the info coming, i'll continue to do my research.

question about the emissions. if i'm using biodiesel to power the beast will that allow emissions to pass any easier, even though the truck didn't originally come with a diesel? also, that year had a diesel as an option, should that steer me toward the 6.2 setup from an ease of inspection standpoint?

[Russell]

6.2L diesel was available in vans and trucks of all shapes and sizes from 82 through 92. In 93 they made the switch over to the mechanically injected 6.5L, then made the switch to an electronically controlled diesel in 94.

[arveetek]

The cheapest and easiest swap would be a 6.2L/6.5L. The GM diesels use the stock Chevy bellhousing bolt pattern, and fit into the stock motor mount locations.

The best way to do a conversion is to buy a complete donor vehicle, and swap over all the necessary parts. Besides the actual engine, you will also need the starter, alternator, power steering pump, A/C compressor (if required), radiator, hydroboost brake system, A/C condensor (if required), exhaust manifolds, etc. All these parts are different from the gassers, and will nickel and dime you to death if you don't get them all at once. A lot of times you can get a complete rust bucket 6.2L truck with a good engine and accessories for $500 to $800.

I've done the swap twice myself, and it's no big deal.

The 6.2L and 6.5L are essentially the same engine. The 6.2L was introduced in 1982, phased out in 1993. The 6.5L, basically a 6.2L with a larger bore, was introduced in 1993, and then in 1994 was given an electronic injection pump. If you get ahold of an electronic 6.5L, it's easy to swap back in the mechanical pump and install it an earlier truck. The 6.5L is still being produced today, by GEP, a division of AMG, who make the H1 Hummers. The military still needs lots and lots of 6.5L engines for their vehicles, so that's why it's still being made.

The 6.2L doesn't deserve the bad rap it got, which was mostly due to the 5.7L Olds diesel, which is a different story. Remember, the 6.2L was designed during the fuel crisis years, and was meant mostly for a fuel economy situation, not a powerhouse. However, it can be made to be a powerhouse, like I did with my engine.

I really like the 6.2L/6.5L family myself.

Casey

[DirtyLarry]

I agree with arveetek, the 6.2 or 6.5 would be the cheapest and easiest swap for this type project. The Cummins 3.9L 4BT has come up a few times but keep in mind that engine is hard to come by as it was used by GM specifically for Frito-Lay in the Chevrolet P30 stripped chassis for only a couple of model years. You will have a hard time coming across one of those as Frito doesn’t let loose of them very often…..and believe me, you do not want to buy anything Frito has for sale. They are not exactly the benchmark fleet in terms of maintenance. The transmission adapters for that engine are even harder to come by and very expensive if you find them as well.

Between 2001 and 2005 Frito also used a Cummins 4BE with an Allison 1000 in their Workhorse P30 vans. DHL also bought a few. There were a tad over 2000 of those Workhorse P30 stepvans with 4BE’s built so they are even harder to come by than the 4BT’s and the companies that own those trucks don’t sell them very often although they can be found in some stationary equipment as well. Most people have never laid eyes on a 4BE or knew they even existed……Here is a picture of one. They shake like hell but run nice. Cummins builds great engines.

[mmusmanno]

Arveetek, what did you do to your 6.2 to make it a powerhouse? and also, what do you think about a '92 chevy g20 van with a 6.2 as a donor?

[arveetek]

Those of you interested in the 6.2L/6.5L family might like to see this website:

http://www.optimizer6500.com/

As far as what I did to my engine, in a nutshell: lowered the compression by topping the pistons, boring the engine to .040" over, installing 6.5L turbo injectors, having the injection pump rebuilt to 6.5L turbo specs, installing a turbo off a 7.3L Ford diesel, and installing 4" exhaust. With all this work, it pulls about the same as a late 90's Powerstroke diesel, which I think is pretty good.

Here's a thread following some of my build-up:

http://67-72chevytrucks.com/vboard/s...d.php?t=141204

Looks like I never really finished up the story, though. I'll have to write that later.

Also, www.thedieselpage.com is a great resource for GM diesels and conversions.

The engine from that van would work just fine, but the other accessories like the radiator and brakes will be different than the truck. You might be better off finding a truck in your body style so you can get all the other stuff you need.

Casey

[mmusmanno]

since i'm having a local mechanic do most of this, here is what i'm thinking. instead of buying an old donor and using old parts and getting an engine that will need much work to make it the workhorse I want. and, since i'm slowly going to totally restore the truck and put a lot of new parts in it anyway. and, since you have done this and could probably give me a list of exactly what parts i'll need to buy, i'm thinking, I take my truck to the mechanic, who specializes in rebuilding engines. get him a old 6.2 for him to start with and make it that bad to the bone powerhouse, then order everything I need from either lmc or whatever place will sell it, based on your list. and replace all the parts I need with new ones. I want to have the drivetrain worked on as well, all the seals, joints, anything. this way I don't have to buy an old donor and literally rebuild everything on it, to put into my truck. and my truck will be on its way to being restored. i'll be doing the interior and body. one last thing, what about emissions? since the truck wasn't originally a diesel, will that be a problem in PA? i'm planning on running biodiesel in it, there is a station about 20 minutes from my house that I can refuel anytime. does that effect emissions? so, Casey, tell me what you think? thanks. Mike

[arveetek]

Mike,

If a restored look is what you're after, I'd start with a factory diesel truck, and then restore that one. Especially if you're going to pay someone to do all this work. You're gonna have a ton of $$$$ wrapped up in this project, just in the engine alone. I spent nearly $3000 on my engine, turbo, and exhaust system alone, and I did the work myself. I would say you'd better plan on 6 to 7 grand to do what you're saying, before you even start on the rest of the truck.

If you try to piece it together, even with new parts, you won't end up with a stock looking rig under the hood. I swapped in my 6.2L back in 1996, and I still haven't gotten all the parts and pieces under the hood yet to where it looks factory.

I'd take some time to research the 6.2L and decide what it is that you really want.

As for the emissions and registration questions, you'll have to find someone from your state to answer those for you, since it varies from state to state. Here in Missouri, we have no emissions checks.

Casey

[mmusmanno]

Casey,
I'm definitely not looking for a stock look under the hood. the reason I wasn't going to buy a donor truck was because I figured the engine would need a ton of work, so, why not just get an engine already done. I can get a local engine shop to do the work on that if I tell them what I want and find any parts that they need, and if I can find someone that will put the engine in, and the local engine shop said they will, but, the one place I called, didn't sound like they knew a lot about diesels, so, i'm looking for one that does. this way they'll be comfortable hooking up the diesel stuff. I can pretty much handle most of the rest. the truck is in pretty good shape, bought it from texas 5 years ago, so, only 5 years of northeast winters. I know its going to be costly, but, it's my critter, and I plan to have it for a long, long time. i'm looking to make it something totally unique and just literally bad to the bone. wolf in sheeps clothing, just something that is one of a kind. and i'm expecting to spend about 10 grand by the time i'm done. I saw one other shortbox diesel last year, it sold for $6500 but would have cost me $1000 to ship it and I don't know what it needed. what about thoughts on turbocharger vs supercharger, what do you think? I realize i'm asking a lot from you, and I really appreciate all your help. if I can go to the local shop with all the parts I need and a list or description of what I want them to do, lets face it, they'll do it and this way they won't have to think about it, I will lay it out for them completely. i'll check out everything you've said so far and ask that if you have a list of everything i'll need to buy/get and how the engine should be set up. some people talk about marine parts, what is that? also, if I can find someone that will put the engine together thats not local, I won't need the engine shop and my local mechanic can do the swap for me, and he's like a friend of a friend, so, it wouldn't cost as much. what should a complete, worked, 6.2 powerhouse cost? thanks.
Mike

[arveetek]

With all the questions you have, I highly recommend you spend the $20 and become a member of www.thedieselpage.com and then read, read, and read! They have books and books on the 6.2L and 6.5L, and I think you need to research all that info so that you can come up with a good idea of what you want. It's too much for me to be able to answer properly here.

The membership for The Diesel Page is the best money ever spent, if you're serious about the 6.2L.

Casey

[mmusmanno]

Casey,
I'm definitely doing that, the twenty bucks is nothing compared to what i'll spend by the time i'm done. I heard Dr. Lee puts together a 6.2 with 300 hp and 430 torque or something like that. I had emailed a guy about a diesel about a year ago and he told me about Dr. Lee, then I found him on the diesel page, so, thats a definite. also, there is a site called dieselpowermag.com that has an actual 6.2 buildup, exactly what they did to make the 6.2 the powerhouse i'm looking for. but, this has been great, now all I need is a local guy that is comfortable converting the gasser to diesel. I found one guy, but he's about an hour away, so, i'm looking for a little closer. once the diesel is swapped, the rest will be an on going process, like you say. but, fun nonetheless, then i'll have my unique shortbox diesel powerhouse. and when I start making my own biodiesel then i'll really be there. thanks again.
Mike