Modifying My Deuce

[jason41987]

I just ran a calculation on the truck, using the 3200rpm governed redline of the 5.9 cummins (just using this as an example) with the stock final drive ratio of the rockwells and an NV5600 6-speed manual tranny. With the 46 inch tires the calculated top speed is 87mph which allows for a 65mph cruising RPM of 2400 RPMs. So if this calculation is remotely accurate a 5.9L cummins with an NV5600 transmission with stock differentials in the rockwells would give me plenty of speed. The transmissions first gear is a bit smaller at 5.63:1 but with nearly double the torque over the stock engine the truck should have MORE pulling power than the stock setup

So theoretically if I went with the disc brake conversion, left the differentials stock, installed an early 24v 5.9L cummins engine and the NV5600 transmission I would have the performance I want. This is assuming of course i go with the 5.9 cummins, I probably won't just for the sake of being a little different and if I could I would probably want to go with a larger displacement, true medium duty truck engine. The next obstacle would be the front end.

 

[swbradley1]

Here is a simple solution and probably safer than anything you have proposed so far.

Take the body off a Deuce or M809 or M939 series truck and put it on one of these chassis.

http://www.kenworth.com/trucks/c500.aspx

Better yet, just take one and paint it 383 green.

 

[porkysplace]

I just ran a calculation on the truck, using the 3200rpm governed redline of the 5.9 cummins (just using this as an example) with the stock final drive ratio of the rockwells and an NV5600 6-speed manual tranny. With the 46 inch tires the calculated top speed is 87mph which allows for a 65mph cruising RPM of 2400 RPMs. So if this calculation is remotely accurate a 5.9L cummins with an NV5600 transmission with stock differentials in the rockwells would give me plenty of speed. The transmissions first gear is a bit smaller at 5.63:1 but with nearly double the torque over the stock engine the truck should have MORE pulling power than the stock setup

So theoretically if I went with the disc brake conversion, left the differentials stock, installed an early 24v 5.9L cummins engine and the NV5600 transmission I would have the performance I want. This is assuming of course i go with the 5.9 cummins, I probably won't just for the sake of being a little different and if I could I would probably want to go with a larger displacement, true medium duty truck engine. The next obstacle would be the front end.

So what is the increase in RPMS to the axle components . These axles are what they are , they were designed for a off-road environment with sloppy tolerences and poor balance . They were state of the art in 1950.

 

[jason41987]

So what is the increase in RPMS to the axle components . These axles are what they are , they were designed for a off-road environment with sloppy tolerences and poor balance . They were state of the art in 1950.

What would you replace them with if you were to do so?

 

[jason41987]

I looked up some of the engine and transmission specs and so far found one repower option that should work well. The NV5600 transmission (has a higher torque limit than the NV4500) with a DT360 engine pushed to the torque limit of the NV5600 tranny. However, I am still looking for some good medium-duty engine/transmission options around the 6.0-6.5 liter range. I am also sticking with manual transmission, I am not a big fan of autos.

 

[porkysplace]

What would you replace them with if you were to do so?

The axles out of one of these are rated for 80mph. http://www.kenworth.com/trucks/c500.aspx

 

[RAYZER]

Those will be some exspensive tires!

 

[TMNT]

Here is a simple solution and probably safer than anything you have proposed so far.

Take the body off a Deuce or M809 or M939 series truck and put it on one of these chassis.

http://www.kenworth.com/trucks/c500.aspx

Better yet, just take one and paint it 383 green.

I love that C500. It's about $600K, but if I had money to burn, I'd have one just for fun.

 

[swbradley1]

I found a new 2013 for over $770k. The red one just looks cool.

 

[Woodsplinter]

Jason, it sounds like you know what you want to do- good luck and keep us posted! We like lots of PICS too!

 

[jason41987]

Jason, it sounds like you know what you want to do- good luck and keep us posted! We like lots of PICS too!

Well, I know what I would like to achieve, but I haven't decided exactly how I will get there. I was looking for some other good engine/tranny options as well as some other ideas for the suspension and front end. The DT360/NV5600 is just one option. Why do the cat 3116 and 3126 and multifuel engines have a reputation for being short lived? Sure there are examples of engines that have been REALLY taken care of, but it seems to be more of the exception than the rule Is it anything that can be fixed or was it just not one of the better engines cat made? And can anyone think of some other good transmissions i should consider for the swap? I've been trying to find a list of other mid-duty engines and transmissions worth looking into but havent found much outside of the common engines youd find in the big three brand trucks.

Also, with the smaller diesel engines such as the 5.9 cummins and DT360 at 250-300hp, how long do these engines last at higher power ratings? (keep in mind with my calculations on either engine and the NV5600 transmission my cruise speed would be about 2400rpms)

Something else I would like to discuss further is what are my options for improving the front end? And is there anything you could think of that may improve either the onroad or offroad characteristics of the rear end? Such as perhaps improving articulation?

 

[rustystud]

Jason, you say you have an engineering degree. Then you would know that you cannot take a double reduction differential and make it move twice it's rated speed without major consequences ! This also applies to the transfer case. Have you even seen the insides of a Rockwell double reduction differential ? There is some major rotating mass in there. You also say you will install a NV5600 transmission. Do you realize how long this tranny is and the length the engine your thinking of installing ? You will have this engine sitting on your bumper, drastically changing the dynamics of your front suspension and steering. From all you have said, it seems like your a young kid dreaming up some kind of wonder truck. Truthfully now, do you really have an engineering degree ?

 

[jason41987]

Jason, you say you have an engineering degree. Then you would know that you cannot take a double reduction differential and make it move twice it's rated speed without major consequences ! This also applies to the transfer case. Have you even seen the insides of a Rockwell double reduction differential ? There is some major rotating mass in there. You also say you will install a NV5600 transmission. Do you realize how long this tranny is and the length the engine your thinking of installing ? You will have this engine sitting on your bumper, drastically changing the dynamics of your front suspension and steering. From all you have said, it seems like your a young kid dreaming up some kind of wonder truck. Truthfully now, do you really have an engineering degree ?

Yeah, I do. But I am not all that knowledgeable in the internal workings of the rockwell axles, nor have I messed around with many diesel engines/transmissions, so I'm just not aware of the overall size of some of these components. That's why I am asking questions here to figure out what could fit, what could work. Also keep in mind that wanting more speed isn't so i can go faster, but so I can cruise at lower RPMs while having the option of a little added power if needed and so far I think a DT360 engine could provide what im looking for, and I originally thought of mounting it to an NV4500 transmission but it doesnt seem to take much to overpower the NV4500.

What do you guys think about the two-stroke detroit diesels like the 6-53 and 6-71s? Which transmissions would you recommend for either of the detroit diesel engines, the DT360, DT408, or any medium-duty truck engine you can think of? I'd like to hear some good engine/tranny combos that you think could provide the power and longevity needed to move the deuce to 55-60 comfortably? And if the axles REALLY won't allow that then I would consider selling off the rockwells and going with another tandem which may not be the worst idea anyway because an axle-upgrade could get me a better braking system too without having to jerry-rig something together)

 

[RAYZER]

If you decide to keep the rockwells, please don't "Jerry rig" disc brakes, you can buy kits for that.

 

[phil2968]

...And is there anything you could think of that may improve either the onroad or offroad characteristics of the rear end? Such as perhaps improving articulation?

http://youtu.be/c23OcwiXRPg
Start watching this video at about 1:30. You will see an A3 deuce attempting to climb a small hill with his Cat engine and his automatic. After he is through trying you will see what a stock A2 deuce can do to the same hill and bigger ones. Notice the rear ends. Come to the Georgia rally in October and you can go up the same hill. In the same truck even!

Why does everyone want to redesign these trucks? They work great as they are. Yes, the brakes could be made safer by going to a split system but the stock system is more than big enough to stop the truck.
If you want fast, an automatic, air conditioning, cruise control (no wait, a stock deuce has that!), go by a Kodiak.
http://www.topspeed.com/trucks/truck-reviews/chevrolet/2003-2009-chevrolet-kodiak-ar133691.html
Do this, get a deuce, learn to work on it, drive it and oh what was that last thing..............,..oh yeah, have FUN with it!

 

[TMNT]

Hey, that's my video! That was my very first rally and it resulted in me buying a deuce a few weeks later.

I agree that stock deuces are awesome. I am strictly keeping mine original and authentic.

However, I've seen some very creative and well done mods. Sometimes it's more about seeing what can be done, and not necessarily about what is cost effective or practical.

I don't agree with all of Jason's ideas, but if he has the skills, time, money and tools then more power to him.

Just put it together right and keep safety first. If you create some 80MPH heap that looks like a deuce and then kill yourself or someone else with it, it would not only be a tragic event for you and your family, it would bring unwanted negative attention to our beloved hobby. So, go build what your heart desires, but engineer and build in safety above all else.

 

[jason41987]

Well as I've stated before, I have no REAL intention of going 80+, but a .72:1 fifth or sixth gear in the transmission would keep highway cruising speeds of 55-65 to 2400rpm and lower. As opposed to practically redlining it and putting serious stress on the engine just to cruise at 50. With the right transmission, or even replacing the fifth gear with a .72:1 gear this could probably easily be achieved with the original transmission. I'm not entirely opposed to keeping the stock engine if I was able to get a little more power out of it (which would require a new transmission anyway) without destroying the engine.

Anyway, can anyone talk me out of pursuing a 2-stroke detroit engine for my deuce? I really love the way these things sound.

 

[TMNT]

There is a member here that sells OD kits for the deuce. Search, but I think it's M35-Tom.

I don't know how much power you want, but you can turn the fuel up quite a bit on the multi-fuel. Install a pyro so you can monitor and manage the cylinder temperature.

There are several members here that have deuces that cruise at 55 or so.

I support your ideas, but I think you should know that people here are very safety and image conscious. We don't want anyone hurt and we don't want a negative public image. The issue of safety will always come up here, whether it's about changing a tire or drag racing. Don't be offended by that. Take it to heart and build your beast.

 

[TMNT]

Anyway, can anyone talk me out of pursuing a 2-stroke detroit engine for my deuce? I really love the way these things sound.

I love that sound as well. I've thought about buying another deuce and putting a Detroit 2-stroke in it just for the sound. I don't think the power band work very well in the deuce, certainly not with the original transmission.

With the cost and effort required to do that project properly, I'd probably be better off buying an old semi with a Detroit in it and restoring it.

I have to admit I occasionally dream about my deuce sounding like this tractor does, especially at the 1:20 mark!

http://youtu.be/ONZKsdTSPHI

 

[jason41987]

Safety is my first priority, which is why I am focusing on brakes, suspension, and making sure it can handle well enough before I change out the engine and transmission to add more power and speed.

I am not very familiar with the detroit diesels on the more intimate level I have never worked on them before. How reliable are they? Still well supported in the aftermarket? How long-lived are the engines? Of the two-stroke detroits, which ones do you think would be best for swapping into a deuce? Is the 6-71 really too long? And lastly, with the stock differentials in the rockwells and considering the engine choice, what would be some of the best transmissions to look around for to complete the swap?