I'm Cummins swapping a '74 Duster, thought I'd share the progress.

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72bluNblu said:
So, I agree, bad idea.

But, before we get too crazy on the weight thing- a 426 street Hemi weighs ~843 lbs dry right? And no one would question the guy if he was putting in a 426 hemi.

I’m seeing specs like 1,150 lbs for a 5.9 Cummins. So, yeah, heavier. And lots of beefing up to do. But I’m not sure it’s absolutely crazy.

Right off the bat though, 325 lb/in springs on an HDK won’t cut it. The 2500 springs are vertical. The motion ratio on those coil overs is gonna mean you’re probably gonna need to be 500+ lb/in on the springs
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Cummins 5.9 weighs a grand if it weighs a pound. Probly closer to 1200
 
rmchrgr said:
I agree with Kern Dog that this idea is ill advised. Just because something can techniclly be done does not mean it should be done. Putting a Cummins into a D150 or something would be a natural swap but shoehorning one into a smaller passenger car makes little to no sense. It's not a passenger car engine, it's a truck engine made to haul heavy loads. You're also going to have a rev limit of less than 4,000 rpm which does not sound fun.

But besides the chassis stuff, how are you going to cool it? Those things run pretty hot (215-220) and could potentially melt stuff under the hood without proper ventilation. You'll also have to science out your fuel system pretty thoroughly to run diesel. And what trans do you plan to use? Whatever it is won't fit without cutting apart all kinds of structural pieces of the chassis. So not only are you adding a bunch of weight up front but weakening whatever is behind it.

I'd think this through a little more before you start cutting stuff making the car un-sellable should you decide to abandon the project before its finished.
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You'd be surprised what you can do with less than 4000 rpm, as far as cooling, I know I can certainly decrease cooling capacity most of the cooling is for heavy hauling anyways, unloaded I've never seen my personal truck nor my work truck exceed 198°F, granted, I'm not doing a lot of hot rodding with either of them but 100+ degree ambient temp in the summer they still run pretty cool. I'm hoping I can just put a 29 inch cold case radiator in it, but at the moment I'm struggling to find any way to calculate the heat load and cooling needed to keep the engine happy.

The fuel system won't be too terrible to figure out, if I use an air dog or a fast fuel system I'll be set. might have to get some bungs welded into the stock tank to make it work, and really all I need is just a level sender for the gauge cluster.

I've got a G56 set up to go in the car, it's a big girth transmission and it will require one hell of a transmission mount, but whatever structure will be pulled out of the car could be made up with the transmission cross member and additional supports around it
 
jos51700 said:
I just want to see how the coil overs do with all that extra weight and no torsion bars.

That said, I'm also curious why you're ditching t bars when you're running such a narrow motor.
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I haven't test fit the G56 yet , but it's quite a big transmission so It might interfere with the hex keys of the torsion bars
 
You might be able to eventually shove that engine in there and make it run and drive but it will never be “safe” to drive on the road. The amount of structure that will need to be removed will make an already flimsy car even worse. Not to mention the weight bias.
Possibly if you are an expert fabricator you could get it strengthened up enough (frame ties, crossmembers, roll cage, etc) to not be a total death trap but by that time you’ll have a ton of time and money in it. But if that’s what you’re after go for it. That’s hot rodding.
 
SSG_Karg said:
You might be able to eventually shove that engine in there and make it run and drive but it will never be “safe” to drive on the road. The amount of structure that will need to be removed will make an already flimsy car even worse. Not to mention the weight bias.
Possibly if you are an expert fabricator you could get it strengthened up enough (frame ties, crossmembers, roll cage, etc) to not be a total death trap but by that time you’ll have a ton of time and money in it. But if that’s what you’re after go for it. That’s hot rodding.
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My goal is to remove as little structure as possible and strengthen as I go, I have no idea what I'm doing but I've put allot of thought into this project, been planning it for 3 almost 4 years now. All that's left to do is go for it and problem solve as I go
 
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Big 20 gallon fuel cell in trunk, turbo under the rear of the car it'll counter the weight better than they think. Put a dana 60 out back. And roll some coal! Why not. Screw LS swapping the world, now it can be cummins swap the world
 
I'm not really sure what you've been thinking about while planning this for 3-4 years but frankly you should have come to the conclusion pretty quickly that an 1,100 + lb engine in an A body is not a good idea. You can theorize/rationalize/explain this all you want but it's just not a reasonable endeavor. What is your vision for this thing besides just "doing something different?" If you're after tons of torque put a stroked 400 in it with stealth heads. It will weigh nearly the same as an iron head small block. If you're after the turbo, put a 360 in it with manifolds and go in the 9s. I'll put you in touch with a guy who can tell you how to do that.

A '73-up Duster weighs 3,400+lbs with a small block but it's going to be over 4,500 lbs when you're finished. Putting a Dana in it will add an extra 100 lbs to that. These cars were never meant to be that heavy, the chassis is not robust enough to handle that kind of mass. Again, a Duster is a "compact" passenger car, not a heavy duty vehicle with a rigid, traditional frame.

Not only that, as has been mentioned already, the front/rear weight bias of these cars is not so great to begin with. By doubling the engine weight over the nose and adding more support, it's going to be more like 75/25. Additionally, a 6BT is a really tall engine so the center of gravity is going to be much higher than it should be. You can probably forget about a hood too.

Just so you're aware, a 29" radiator is not fitting in an A body. Standard width is 22". With a 28" radiator half of it will be behind the radiator support panels with no air flow. Or are you cutting the radiator support out too?

That giant Mercedes truck trans is not fitting in that chassis without major alterations either so you're going to be cutting apart major structural sections of the car without any real sound engineering behind it. Forget that the chassis is also 50+ years old and probably fatigued from years of use and abuse. Understand that guys can barely fit a Tremec in these cars without major surgery so don't think you're just going to cut a little here or there and drop it in like it was meant to be.

Got a chassis jig to keep things straight when you start cutting and welding? If you're not a skilled fabricator or work in a body shop with pro-level equipment (does not sound like it), you're going to be in over your head. All that cutting and welding will put a bunch of heat into the metal, it's never going to be straight. It will also work harden when it flexes making it brittle and prone to cracking. You'd be better off having someone put a tube frame in it and work from there instead of modifying the original chassis beyond what's reasonable.

I'm not saying that you can't do this dude, I'm saying that you shouldn't. It's a misguided idea at best and will not be safe. Save the diesel for a truck where it belongs.
 
rmchrgr said:
I agree with Kern Dog that this idea is ill advised. Just because something can techniclly be done does not mean it should be done. Putting a Cummins into a D150 or something would be a natural swap but shoehorning one into a smaller passenger car makes little to no sense. It's not a passenger car engine, it's a truck engine made to haul heavy loads. You're also going to have a rev limit of less than 4,000 rpm which does not sound fun.

But besides the chassis stuff, how are you going to cool it? Those things run pretty hot (215-220) and could potentially melt stuff under the hood without proper ventilation. You'll also have to science out your fuel system pretty thoroughly to run diesel. And what trans do you plan to use? Whatever it is won't fit without cutting apart all kinds of structural pieces of the chassis. So not only are you adding a bunch of weight up front but weakening whatever is behind it.

I'd think this through a little more before you start cutting stuff making the car un-sellable should you decide to abandon the project before its finished.
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I know of D and W 100 or 150 series trucks people have 6BT swapped that came apart within two months of heavy use. The diesel frame has larger webs and rails and extra crossbraces in it. And that's with swapping in 3/4 ton axles and suspension. The only car I can think of that is suitable for a 6BT swap is one of those Imperials with the big X welded frame that was banned from the demolition derby, but with the front suspension swapped to a full ton van unit and a 3/4 ton or larger rear axle.
 
rmchrgr said:
I'm not really sure what you've been thinking about while planning this for 3-4 years but frankly you should have come to the conclusion pretty quickly that an 1,100 + lb engine in an A body is not a good idea. You can theorize/rationalize/explain this all you want but it's just not a reasonable endeavor. What is your vision for this thing besides just "doing something different?" If you're after tons of torque put a stroked 400 in it with stealth heads. It will weigh nearly the same as an iron head small block. If you're after the turbo, put a 360 in it with manifolds and go in the 9s. I'll put you in touch with a guy who can tell you how to do that.

A '73-up Duster weighs 3,400+lbs with a small block but it's going to be over 4,500 lbs when you're finished. Putting a Dana in it will add an extra 100 lbs to that. These cars were never meant to be that heavy, the chassis is not robust enough to handle that kind of mass. Again, a Duster is a "compact" passenger car, not a heavy duty vehicle with a rigid, traditional frame.

Not only that, as has been mentioned already, the front/rear weight bias of these cars is not so great to begin with. By doubling the engine weight over the nose and adding more support, it's going to be more like 75/25. Additionally, a 6BT is a really tall engine so the center of gravity is going to be much higher than it should be. You can probably forget about a hood too.

Just so you're aware, a 29" radiator is not fitting in an A body. Standard width is 22". With a 28" radiator half of it will be behind the radiator support panels with no air flow. Or are you cutting the radiator support out too?

That giant Mercedes truck trans is not fitting in that chassis without major alterations either so you're going to be cutting apart major structural sections of the car without any real sound engineering behind it. Forget that the chassis is also 50+ years old and probably fatigued from years of use and abuse. Understand that guys can barely fit a Tremec in these cars without major surgery so don't think you're just going to cut a little here or there and drop it in like it was meant to be.

Got a chassis jig to keep things straight when you start cutting and welding? If you're not a skilled fabricator or work in a body shop with pro-level equipment (does not sound like it), you're going to be in over your head. All that cutting and welding will put a bunch of heat into the metal, it's never going to be straight. It will also work harden when it flexes making it brittle and prone to cracking. You'd be better off having someone put a tube frame in it and work from there instead of modifying the original chassis beyond what's reasonable.

I'm not saying that you can't do this dude, I'm saying that you shouldn't. It's a misguided idea at best and will not be safe. Save the diesel for a truck where it belongs.
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With all of the research I've done and all of the considerations and planning up to this point that I've done, I have most definitely come to the conclusion that this is a bad idea and incredibly stupid, but there's only so much planning that can be done before actually attempting to put things in motion. that's the nature of building and modifying cars. Great things often come from dumb ideas.

Ultimately with this car, I'm just trying to build something unique and not boring. I also just fell in love with diesel engines the more I learned about them in school. You don't see many diesel powered muscle cars (for good reason) but that's all the more reason to do it, I'm also just trying to show people that diesels aren't just for trucks, you can make genuinely fun and fast diesel powered cars (which is kind of the point of the YouTube channel as well)

when's the last time you were genuinely impressed with a turbo V8 build of a car?

For me it was probably the 5th or 6th time seeing one, after that it was just kind of boring.

I am aware that the 29 inch radiator won't fit with the stock core support, I'd prefer not to just cut up the one in the car, so I'll end up fabbing a core support.

I know the transmission is huge, I know the chassis is old and tired, is there sound engineering behind any of this? No, I'm just a Generator Technician with an incredibly dumb idea. I know this is going to be an incredible amount of work and there are most definitely skills I don't have that I will need with this project, so I'll learn as I go.

A tube chassis would probably be the best way to go about this, I agree. I also agree what I'm doing is unreasonable and it's a misguided idea at best, and I most definitely shouldn't proceed with this project, but I have a vision for the car and until I hit a point where it's full stop, nothing is going to work. I'm going to proceed and attempt to build this car, I mean what's the worst case scenario? I weld all of the sheet metal I've cut to figure out placement of the engine and trans back in, swap to a tubular kmember and throw a V8 back in it?

There is thought behind all of this and I'm not just going to blindly be cutting and welding. I'm going to save what I remove and do the best I can to ensure my car wont be ruined. I've owned it since 2016 and I love it, even though the stock drivetrain that was in it was in terrible shape and it barely ran as is.
 
I say do it. Absolutely zero reason not to. Straight axle swap it. Gasser stance and shorty stack thru the hood. Mint. The car will hold it especially with engine set back. I have derbied dozens of pinch frame mopars. They take quite a bit.
 
Ok, I'll throw my hat in the ring here, Daniel, I say go for it, it's your car, it's not rare, you thought it threw the best you can, sure conceptually it's not a good idea, and yes you should probably just put the body on a tube chassis AND you may just end up doing that to hold it all together. Maybe it won't work, what's the worse case scenario? You have a basicly rust free parts car?, or maybe you put it back together. At the end of the day what he is doing is hot rodding, something I've always been a fan of as I appreciate the creative mind it takes to do it. IF it isn't safe then don't put it on the road, take it to the track and do some burn outs, put it in a magazine. What ever you do, don't get discouraged, stay on track, and most of all keep us posted!
 
mopar56 said:
Ok, I'll throw my hat in the ring here, Daniel, I say go for it, it's your car, it's not rare, you thought it threw the best you can, sure conceptually it's not a good idea, and yes you should probably just put the body on a tube chassis AND you may just end up doing that to hold it all together. Maybe it won't work, what's the worse case scenario? You have a basicly rust free parts car?, or maybe you put it back together. At the end of the day what he is doing is hot rodding, something I've always been a fan of as I appreciate the creative mind it takes to do it. IF it isn't safe then don't put it on the road, take it to the track and do some burn outs, put it in a magazine. What ever you do, don't get discouraged, stay on track, and most of all keep us posted!
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Thank you very much, it seems you understand what I'm trying to do! I'll post updated pictures and videos whenever I can. Currently working full time with a significant amount of over time so I'm filming and working on the car when I can.
 
Daniel Garcia said:
when's the last time you were genuinely impressed with a turbo V8 build of a car?
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Turbo cars never cease to amaze me, especially this one. It (was) a basic 360 with manifolds. Low buck build up, heavy car. 9 seconds. Different combo now but when it was a turbo small block it was super impressive.
mcp_7008-1280x848-1280x848-jpg.223075


Anyway, I really don't get the point of what you're doing. If you answered me sincerely then I have to really question your understanding of what is being discussed. What you are proposing to do is not logical and if you somehow follow through with it will be unsafe for a myriad of reasons, most of which have been outlined here repeatedly. If you're going to ignore logic and do it anyway then basically you're just looking for attention which is completely lame.

Understand that you are mistaken in thinking you can just cut out structural parts of a uni body chassis and weld them back together like nothing happened. That is a false notion. One you cut stuff out of the chassis, there's no going back. To repair structural parts properly, all the original spot welds holding whatever it is in place would have to be drilled out of the sheet metal and new or good used parts would get spot welded back in. The frame rails and cross members are stamped steel which is where they get their strength. Those pieces are generally not meant to be cut out and/or welded back together. Can it be done? Sure. Is it right? 99% of the time, no. Look through the cars being parted out classified forum. "Rusty frame" is probably the first thing you read. Once a unibody chassis is compromised, it's pretty much toast.

What I'm saying is that once you start cutting stuff up, the car is essentially going to be junk before you put the engine in. You admit you don't know what you're doing which only increases the chance of junking the car before you even drive it.

People will tell you to go for it or yeah, that's so cool man or it's your car do what you want and don't forget to take pictures but they don't give a rats ***. If you're happy turning what seems like a currently viable car into a pile of ****, go for it.
 
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