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Opinons on Cummins swap...

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Wondering what y'all think about a 800 lb engine in a 720. Is that too much to ask of the 4wd suspension? Planning on using big coilovers, dead set against sas.

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Let's see.......Cummins (turbo of course) is twice as tall as the stock motor, twice as long as the stock motor, about 8 times heavier than the stock motor, and we won't even discuss the sideways torque.

 

Just off the top of my head, I would say....no.

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The T-100 would never handle that. Sometimes a free engine is just too damn expensive.

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I put a 24v Cummins in a 1954 GMC a few years ago, and the valve cover could have been used as an arm rest. The motors are very long. I would be all for it if I thought you would ever finish the project, but most of these "crazy idea" projects never get finished.

 

Yes, it would probably be too heavy.

 

 

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The 4 cylinder (4BT I think) is just as tall as the 6 cylinder used in the Dodge pickup, just shorter. It's TALL, way too tall for a Datsun pickup.

 

Don

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yes the 4bt is tall, because it was used in swathers and skidsteers and stuff. If you were to put any cummins in a datsun the only one to even consider would be the r2.8 which is easier to get anyhow since it is a fully ready to go crate motor, but I am unsure of the dimensions

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6.6 duramax! Wait I have that in a full size Silverado. Work on turbo remove cab! Actually any kind of work, remove cab. Seriously if you want a diesal the Volkswagen tdi, but this will cost first born. 

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I've been dying to do an R2.8 swap. I know a few guys who have used them and they are totally different animals from that piece of shit they call the 4BT. But yes, they are large. On the other hand, since Cummins made a point to offer them as a crate engine, there is a growing aftermarket for them.

 

 

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Boils down to two things, not enough room and the suspension/running gear can't handle the power/torque.

 

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You could get the D21 V6 transmission/transfer case and diffs, they are pretty beast.  Seems like a lot of work though.  

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If you want to go that route might as well buy an old Dodge 4x4 with the 12 valve Cummings and drop the 720 body on top. Be much cheaper but will still have to extend the 720 body about two feet on the front to make room for motor and radiator. Height won't matter, just lift body until there is room.

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I just got three weeks ago A 1992 Dodge w250 xcab 4x4  Cummins 12 valve  diesel manual 5spd  167k Dana 60 and 70 lsd  Best truck ever maybe !, will post after new front leaf and minor front end rebuild , goodbye Toyota  it gets about same  18mpg in town .

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3 hours ago, weldingrod said:

Boils down to two things, not enough room and the suspension/running gear can't handle the power/torque.

 

 

This is pretty much a thought experiment. Like a 426 hemi in a Radioflyer.

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50 minutes ago, hosestop@msn.com said:

I just got three weeks ago A 1992 Dodge w250 xcab 4x4  Cummins 12 valve  diesel manual 5spd  167k Dana 60 and 70 lsd  Best truck ever maybe !, will post after new front leaf and minor front end rebuild , goodbye Toyota  it gets about same  18mpg in town .

Now I AM irritated. Sold my 1993 50 xcab 4x4 with same driveline.  The '93 had the one ton running gear.You are getting about what the new trucks are getting but no matter how often I checked, was getting around 27 mpg town and highway with a camper on. Maybe different gears in the one ton? That was better milage than my '84 720 Nissan. In all fairness, I do know the 720 needs a carb rebuild.

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lyIPY0k.jpg Here it is have not been on here much because new pc and forgot imgur.

Edited by hosestop@msn.com
I am on it mostly because it is new to me doing a few thingd inclding governor spring and some shim thing gets like 80 hp more

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I didn't bother to look at the dimensions. Scratch that idea I suppose. I too bought a W250 Club Cab, after driving it thats what sparked the idea that it'd be worth cutting into the 720 firewall. The torque is wonderful.

 

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I know a few guys that have 12v Cummins motors in their rock crawlers, and while they do make tons of torque, the weight is a killer. I would rather be light and nimble.

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The problem with diesel engines is they sound so stupid.  Well except one.  Turns out there is always an exception to every rule!  

 

 

 

 

 

 

 

 

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Can't beat the sound of a 2 stroke detroit. I just scratched the whole idea, the idea was find a 4 door 720, make it 4x4, turbo diesel, and able to run on waste motor oil. For several reasons, I have scratched that idea. too expensive, can't find a turbo diesel thats both light and has decent power with a mechanical injection pump. And I also already have the Cummins, that is 4x4, I'm just gonna soup it up for long Datsun retrieval and/or hunting trips out west. I already have a long bed 720 project, and a KC 620 race truck project. Not to mention I wanna restore a stockish 620 KC for my old man. He's 80 this year and isn't too crazy about aftermarket stuff lol.

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If you really must have a diesel, consider a 3cylinder Yanmar. Don't know if adaptors are available to the tranny, though.

 

Big deal in Europe right now, people putting Cummins into old American built cars.

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On 8/8/2019 at 7:05 PM, weldingrod said:

Now I AM irritated. Sold my 1993 50 xcab 4x4 with same driveline.  The '93 had the one ton running gear.You are getting about what the new trucks are getting but no matter how often I checked, was getting around 27 mpg town and highway with a camper on. Maybe different gears in the one ton? That was better milage than my '84 720 Nissan. In all fairness, I do know the 720 needs a carb rebuild.

I think your math is a little off on those fuel mileage numbers.

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You want diesel, i would look Mercedes om617.  3 litre turbo, good size to fit 720 and can be built to reasonable power numbers without the insane weight of some other options.

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The Cummins is great so far 18-20 mpg and I am not trying for gas mileage ! 6300lbs of metal with a  5spd getrab trany will post restoration of this in Off topics soon . 

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