Diesel Swap: Cummins VS GM 6.5

[half k cruiser]

When last I looked at the diesel adapters kit it was almost $10k ! That's a lot of money added on top of finding a donor vehicle / motor. If that's the case you have to easily be getting into the range of an OEM diesel. Granted I think the other poster might be onto something with a v8 swap. You could add a lot of power and easy serviceability.

 

[shocktower]

When last I looked at the diesel adapters kit it was almost $10k ! That's a lot of money added on top of finding a donor vehicle / motor. If that's the case you have to easily be getting into the range of an OEM diesel. Granted I think the other poster might be onto something with a v8 swap. You could add a lot of power and easy serviceability.

Yes, you pay to play, do you know how many part's are involved in a complete swap ? I know doing a V8 swap it is close in cost, and you get the same MPG as a stock one. I did mine and happy as a pig in Mud, people complain about the cost, but the end results are phenomenal and worth every dollar, so unless you have driven one and in the really know, you don't have an idea, I wanted to do a swap on mine since I bought it, I knew the body and chassis was great just lacking power, and for some up front money, I have it

 

[maxamillion2345]

The stuff from dustin is nice but his CS is dissapointing from the stuff I've read. Probably the easier and better route than custom fabbing everything like I did though. Theres a lot of time invested in trying to make things work that dustin has figured out already. A lot of trial and error. Its a lot of money but for most, the kit will be the only option anyway as most possess neither skills nor tools and probably not the time either.

I'd personally find a p pump 215 hp 6bt if I did it again.

Not sure if Dustins trans tuning is better than duisers but that was an issue I know.

 

[bloc]

Someone asked about using the stock toyota transmission. NOPE.

The 6BT fits better the the stock motor

I understand being proud of your swap but lets be reasonable here..

I know doing a V8 swap it is close in cost, and you get the same MPG as a stock one.

If not regeared the v8 swap guys are generally getting slightly better than stock mileage, on fuel that is cheaper than diesel. Not that it matters for anything other than fuel tank range.. anyone thinking they'll offset any significant portion of a diesel swap in saved fuel is jaded. Which makes the mileage point pretty much moot. Besides.. once people start dropping in GenV direct-injected v8s I suspect they'll be matching or beating the ~6Liter diesel FE numbers on RUG. These engines are relatively cheap too, as few people are using them yet and they have a couple hurdles to jump (vacuum pump, etc). But LOTS of power for the displacement and very good mileage.

And for the record I'm not s***ting on diesel swaps.. If the 6bt weren't so heavy I'd most likely have one in my rig instead of my all-aluminum V8. But at least be honest with the info we are providing.

 

[maxamillion2345]

Swap in an anemic V8? Meh. I'd rather have a turbo 6.5

Thats not directed at you Bloc, fyi.

 

[bloc]

Swap in an anemic V8? Meh. I'd rather have a turbo 6.5

Thats not directed at you Bloc, fyi.

I know it's not.

But.. you should go for a ride in a rig with a gas 6.2 and see if you still think it's anemic.

 

[maxamillion2345]

I wouldn't think it was. But most swaps don't seem to be of the 6.2 variety. Or even a 6.0 for that matter.

 

[shocktower]

The stuff from dustin is nice but his CS is dissapointing from the stuff I've read. Probably the easier and better route than custom fabbing everything like I did though. Theres a lot of time invested in trying to make things work that dustin has figured out already. A lot of trial and error. Its a lot of money but for most, the kit will be the only option anyway as most possess neither skills nor tools and probably not the time either.

I'd personally find a p pump 215 hp 6bt if I did it again.

Not sure if Dustins trans tuning is better than duisers but that was an issue I know.

Yes Dustin had some issues in CS, part of it was not of his control, and now he is using a new stand alone ( I have the first one) which is 100x better the compushift, people are quick to bash, but do not know the whole story. Doing all of the manufacturing/design and doing installations, also improving/developing product's all the while having a life, is not easy. If it was so easy everyone could do it

 

[shocktower]

Someone asked about using the stock toyota transmission. NOPE.



I understand being proud of your swap but lets be reasonable here..



If not regeared the v8 swap guys are generally getting slightly better than stock mileage, on fuel that is cheaper than diesel. Not that it matters for anything other than fuel tank range.. anyone thinking they'll offset any significant portion of a diesel swap in saved fuel is jaded. Which makes the mileage point pretty much moot. Besides.. once people start dropping in GenV direct-injected v8s I suspect they'll be matching or beating the ~6Liter diesel FE numbers on RUG. These engines are relatively cheap too, as few people are using them yet and they have a couple hurdles to jump (vacuum pump, etc). But LOTS of power for the displacement and very good mileage.

And for the record I'm not s***ting on diesel swaps.. If the 6bt weren't so heavy I'd most likely have one in my rig instead of my all-aluminum V8. But at least be honest with the info we are providing.

Diesel is cheaper here, and I love the idea of going 400 miles on one tank, I have more than doubled my mileage, and I have not yet re geared it, which will even get better, and there is no electronic fuel injection, a very simple set up, nothing to deal with on mapping, the injectors and transmission

 

[Blake Loggins]

Gering is definitely a concern with this swap. I know you can buy 3.54 gears from Marks but will they work with my lockers? Or can I purchase new lockers for the 3.54 gears?

It seems to me it would be easier to use the Dodge 47r auto transmission. The 4th gear ratio is .69 vs the Toyota trans being .765. Thats about 400-500 rpm difference at 75. That should put rpms closer to 2000 at 75mph. So, has anyone done this swap with the 47r and NP205 transfer case? (forgive me if thats a dumb question) BTW I really don't want to go the NV4500 route.

 

[bloc]

I'd have serious concerns about the Toyota transmission handling the torque of either of these engines, especially if you want the power levels it sounds like you do.

You can get overdrive 80-series transfer case high-range gears to help overall ratios as well. Would be easier than regearing the axles, though I'm not sure how far the ratios can go.

 

[cjmoon]

Diesel is cheaper here, and I love the idea of going 400 miles on one tank, I have more than doubled my mileage, and I have not yet re geared it, which will even get better, and there is no electronic fuel injection, a very simple set up, nothing to deal with on mapping, the injectors and transmission

You are laying down some serious numbers in the mpg catigory. You must drive like my 93year old grandfather. I have not seem any one claim better the 20. That's the best I've ever done also on a road trip at 70-75 mph with 3.54 gears. Start adding power and ypu will use it. Mpg will suffer

Gering is definitely a concern with this swap. I know you can buy 3.54 gears from Marks but will they work with my lockers? Or can I purchase new lockers for the 3.54 gears?

Done 3.54 gear install with both factory lockers and ARB so you should be good there.

I didn't think overdrive gears where avalible for the full time case? Only the part time 60 case?

 

[wardharris]

I didn't think overdrive gears where avalible for the full time case? Only the part time 60 case?

We have 10% overdrive, 10% underdrive and 3:1 crawler gears for 80 and 100 Series transfer cases, all Japanese via Terrain Tamer of Australia. Both modified gear sets can be installed in the full time T-Case. @orangefj45 - Georg Esterer of Valley Hybrids is the gear guru....

 

[maxamillion2345]

Yes Dustin had some issues in CS, part of it was not of his control, and now he is using a new stand alone ( I have the first one) which is 100x better the compushift, people are quick to bash, but do not know the whole story. Doing all of the manufacturing/design and doing installations, also improving/developing product's all the while having a life, is not easy. If it was so easy everyone could do it

Well having sourced everything myself, everything being one off and custom I understand exactly how difficult it is. That being said, I could and would not be able to offer a kit. Its cool that he does but charging 10k I would not expect excuses and to be ignored for lengthy periods of time. If I couldn't deliver on my promises I'd cease to make them. I'm a pretty understanding guy, I've worked in similar industries, I know how these things go but his lack to communication and fairlure to fulfill orders and promises goes beyond that. I'm sure hes a great guy and its a great product but there are some shortcomings in CS.

Not trying to rain on anyones parade or bash on Dustin but I hope people know what theyre getting into when they order. I was doing my swap around the time duiser/jonesys started on their first swap so I've been following along with most of the swaps since.

 

[maxamillion2345]

I get ~17 going 75 on 40s with 4.56s just for reference. The range with my WJ tank is excellent. I was actually amazed how far I pushed it once.

 

[greentruck]

Have only heard about the GM...

Used to help maintain the 6BT, used in our yard tractors, humping semi-trailers around the lot. You know it can fit, but requires some work. Cooling should be workable even under high power demand, as the Capacity yard tractor doesn't have a particularly huge radiator even in this very heavy-duty application.

The trannys in our application were all Allison. Not sure that will fit an 80, but they were about as bulletproof as the 6BT.

Basically, you can dial up the 6BT to whatever power need you'll ever have in an 80 and can be sure it will remain reliable. If a forklift engine suits from the OEM (the F block), then something that moves the semis that a forklift loads is gonna do you right, all else being equal. Think you've already decided on this path, but this should reassure since you're concerned about power.

 

[shocktower]

Well having sourced everything myself, everything being one off and custom I understand exactly how difficult it is. That being said, I could and would not be able to offer a kit. Its cool that he does but charging 10k I would not expect excuses and to be ignored for lengthy periods of time. If I couldn't deliver on my promises I'd cease to make them. I'm a pretty understanding guy, I've worked in similar industries, I know how these things go but his lack to communication and fairlure to fulfill orders and promises goes beyond that. I'm sure hes a great guy and its a great product but there are some shortcomings in CS.

Not trying to rain on anyones parade or bash on Dustin but I hope people know what theyre getting into when they order. I was doing my swap around the time duiser/jonesys started on their first swap so I've been following along with most of the swaps since.

Well all of the parts involved, in the kit's are machined by Dustin, he has rough castings done, and now he powder coats/anodizes all of the stuff and there are some new things, when you break a kit down I believe there are about 65 parts, which most are developed and machined by him, now there is an exhaust system which is mandrel formed not some midas crap, so when you break it down you pay about $135 a part. He does everything himself, that is shipping machining, developing design and testing and CS, there is only so many hours in a day, he moved last year and is still settling in, he had to build a new shop and run a business, he is going to expand his shop this summer, he has been getting better, and it is tough he had some real issues with compushift, which will dictate how the wiring harness is configured, he has since changed to s new one, with great CS from them.

 

[half k cruiser]

Yes, you pay to play, do you know how many part's are involved in a complete swap ? I know doing a V8 swap it is close in cost, and you get the same MPG as a stock one. I did mine and happy as a pig in Mud, people complain about the cost, but the end results are phenomenal and worth every dollar, so unless you have driven one and in the really know, you don't have an idea, I wanted to do a swap on mine since I bought it, I knew the body and chassis was great just lacking power, and for some up front money, I have it

Whoa there turbo, I think everyone on the forum knows how enamored you are with your swap. At no point in my post did I say the diesel adapters kit wasn't worth it. I simply stated that it was a lot of money. I also stated that for the same money you can be in the ball park of a lot of options. For instance 1HD-T , GM v8 , turbo 1FZ, supercharged and re-geared 1FZ, lots of options. Maybe the OP hadn't really thought of those things. Or maybe the OP has a lot of free $$$$ on hand and is dead set on a domestic diesel. In that case it sounds like the Cummins would be a real winner for him.

 

[Mr Cimarron]

Unless you are dead set on staying with the Toyota transmission I would go the route that doesn't need Dustin's kit for install. If you choose 6BT/NV4500/Splitcase the only thing needed from Dustin would be the accessory rail thermostat housing combo for ease of install. There is a lot of the kit I just don't understand. Things like the throttle linkage and intercooler routing.
Dustin has a lot of CS fixing to do before he gets in good standing with some of the former customers. I really hope he gets to that point.

 

[Blake Loggins]

Unless you are dead set on staying with the Toyota transmission I would go the route that doesn't need Dustin's kit for install. If you choose 6BT/NV4500/Splitcase the only thing needed from Dustin would be the accessory rail thermostat housing combo for ease of install. There is a lot of the kit I just don't understand. Things like the throttle linkage and intercooler routing.
Dustin has a lot of CS fixing to do before he gets in good standing with some of the former customers. I really hope he gets to that point.

I really do not want to add a clutch. I'd rather keep it an automatic. I'm stick with the Toyota trans until it breaks. Then maybe a 4L80E and adapt back to the LC transfer case.