An easier way to turbo an M800 truck

[JasonS]

I know that the title is a big claim but I really do think that this worked out well.

1. I used of a factory Cummins crossover tube (14224 and intake manifold. This particular intake retains the flame heater. While the turbo outlet and crossover inlet don't exactly line up this is easily fixed with two 23 degree silicone elbows and an inline coupling between the two.
2. I initially tried to simply bend the hood crossmember out of the way of the crossover tube but this didn't quite make it. In the end, I did have to slightly relocate the hood crossmember. Simply drill out the spot welds, move back one bolt hole and reweld. There was plenty of slop to enable the slight move. There was a slight bump out on the side of the hood where the factory bent the hood to make the crossmember fit. Your hood may be different.
3. The coolant reservoir was moved slightly up and to the rear; remounted on a steel plate. I removed the original brass elbow on the coolant reservoir, welded on a new 90 degree, then 45 degree silicone hose, then aluminum pipe to connect to the engine coolant return. New parker hose and fittings reconnect to the radiator and coolant manifold.
4. The exhaust is aftermarket from PAI for a big cam. Part numbers rear to front: 3062568, 3062566, and 3065024. I am using the turbo in a "low" location, not all aftermarket exhaust manifolds have the dowel holes or enough flange to allow for the dowel holes to be drilled.
5. BHT3B turbo with 26cm housing, 167050.
6. The turbo drain line started with a stock multifuel flange/ pipe which was re-clocked to meet with a 1" 45 degree hose barb threaded into a 1" NPT bung welded into the original block cover plate.
7. The stack is from Amazon and hung with brackets from Amazon. There is a 45 degree elbow to fit through the fender, then a 90 degree, then a bellows from Summit Racing, another 90 degree elbow, straight section, then a flange to the turbo. I did have to cut the 90 degree fitting coming off the 45 at a slight angle to get things to line up. I used a quick connect flange to separate the stack between the 45 and 90 degree elbow.
8. I am using a 5.5" to 5" reducing elbow, then 5" pipe, then a 90 degree to the air filter. This part is not fully complete yet.
9. Unfortunately, I have not heard it run. It has been -13F and I have been unable to take it out or run it yet.

Let me know if you have any questions or comments.

 

[DeMilitarized]

I know that the title is a big claim but I really do think that this worked out well.

1. I used of a factory Cummins crossover tube (14224 and intake manifold. This particular intake retains the flame heater. While the turbo outlet and crossover inlet don't exactly line up this is easily fixed with two 23 degree silicone elbows and an inline coupling between the two.
2. I initially tried to simply bend the hood crossmember out of the way of the crossover tube but this didn't quite make it. In the end, I did have to slightly relocate the hood crossmember. Simply drill out the spot welds, move back one bolt hole and reweld. There was plenty of slop to enable the slight move. There was a slight bump out on the side of the hood where the factory bent the hood to make the crossmember fit. Your hood may be different.
3. The coolant reservoir was moved slightly up and to the rear; remounted on a steel plate. I removed the original brass elbow on the coolant reservoir, welded on a new 90 degree, then 45 degree silicone hose, then aluminum pipe to connect to the engine coolant return. New parker hose and fittings reconnect to the radiator and coolant manifold.
4. The exhaust is aftermarket from PAI for a big cam. Part numbers rear to front: 3062568, 3062566, and 3065024. I am using the turbo in a "low" location, not all aftermarket exhaust manifolds have the dowel holes or enough flange to allow for the dowel holes to be drilled.
5. BHT3B turbo with 26cm housing, 167050.
6. The turbo drain line started with a stock multifuel flange/ pipe which was re-clocked to meet with a 1" 45 degree hose barb threaded into a 1" NPT bung welded into the original block cover plate.
7. The stack is from Amazon and hung with brackets from Amazon. There is a 45 degree elbow to fit through the fender, then a 90 degree, then a bellows from Summit Racing, another 90 degree elbow, straight section, then a flange to the turbo. I did have to cut the 90 degree fitting coming off the 45 at a slight angle to get things to line up. I used a quick connect flange to separate the stack between the 45 and 90 degree elbow.
8. I am using a 5.5" to 5" reducing elbow, then 5" pipe, then a 90 degree to the air filter. This part is not fully complete yet.
9. Unfortunately, I have not heard it run. It has been -13F and I have been unable to take it out or run it yet.

Let me know if you have any questions or comments.

Good write up for those with A0/1 M939 trucks too! For some cheap power this would be a good mod but personally I don't see the time and effort worth it without an intercooler. On my 8.3 my aftercooler coolant temp reaches +300F with coolant temps at 180 on long hills which means the intake air is likely much warmer than that. Each degree increase on the intake is a degree increase on the exhaust side which means depending on very specific circumstances you could be making a net equal hp to NA. Just my thoughts and it may be much different with the NHC250.

 

[JasonS]

Good write up for those with A0/1 M939 trucks too! For some cheap power this would be a good mod but personally I don't see the time and effort worth it without an intercooler. On my 8.3 my aftercooler coolant temp reaches +300F with coolant temps at 180 on long hills which means the intake air is likely much warmer than that. Each degree increase on the intake is a degree increase on the exhaust side which means depending on very specific circumstances you could be making a net equal hp to NA. Just my thoughts and it may be much different with the NHC250.

Thanks. For this size engine and horsepower, Cummins didn't aftercool (at least to the best of my knowledge). Others who have done this mod have reported lower EGT numbers and have been able to increase the fuel.

 

[Superthermal]

Thanks. For this size engine and horsepower, Cummins didn't aftercool (at least to the best of my knowledge). Others who have done this mod have reported lower EGT numbers and have been able to increase the fuel.

Still planning on this mod down the road. It is so cool to see the application of skill by so many to make their mod work. I would like to run a water to air aftercooler just as insurance for my lead foot.
With what you have here, I like the exhaust. The matching your turbos output to the stock intake is excellent! The coolant tank mount is boss as are your oil return plate and drain. The use of a "stock" intake manifold with a heater is cool as well.
Getting a pyro on there would be important, and maybe a boost gauge for fun.
Looking forward to the rest of your build.
I cant tell you how envious I am of you having a shop to work in. Wow that must be nice!

Best wishes

 

[US6x4]

That setup looks good, clean, open, and simple. I like the retention of the cold start pieces and I'm glad I didn't see any plumber's tape anywhere.

 

[muthkw25]

Thanks. For this size engine and horsepower, Cummins didn't aftercool (at least to the best of my knowledge). Others who have done this mod have reported lower EGT numbers and have been able to increase the fuel.

I just turboed my m925a1 and I used a bigcam aftercooler and crossover pipe. I saw 300 degree drops in egts and that's with the probe in cylinder 6. That's with no core in the aftercooler as well. I saw 12lbs of boost peak. With 12lbs there's not enough boost to cause big issues with intake temps. I have a #27 button pump built by premco and adding 10% over injectors from premco this weekend. With my modest fuel settings I won't have an issue however, I have decided to run a n14 intake instead and run a small intercooler to help. I also have a methanol kit installed as extra.

I don't think you'll have any issues. You could also install a methanol kit if you wanted some peace of mind.