I'm planning engine swap to turbo - Which engine to get?

[dma251]

I'm planning my turbo'd engine swap on my M813 soon and I've got a dilemma about which motor to get. A friend of mine has a low-use 855 ci Cummins with the piston coolers, turbo setup, complete (is this the NTC-290?) he'll sell me for $2000. It's apparently a small cam 855 but puts out somewhere around 335 hp. It was installed as a pump of some sort in a stationary mount.

I've also been bouncing around the idea of swapping in a big-cam cummins.

What do you all think I should do? How much can I expect to pay for a big-cam motor? What could I get for my old 250 cummins?

Is it a major undertaking to get the bigcam in? Does it bolt to the bellhousing?

What would you all do?

 

[TheBuggyman]

Funny that you bring this up as I've been thinking the same thing! I found a used 855 small cam with turbo on Ebay that was in my county and could not bring myself to buy it with my dump project going on......
I think that it is a great idea if it all bolts together but I wonder on the horsepower limitations of the stock drivetrain. Does anyone have the lb-ft ratings of each component?
I'm not sure but it looks like the cab heater will have to leave the enginge bay to make room for the turbo motor.

 

[m139h2otruck]

I've looked at the 855 as installed in the 800 series truck, and the biggest problem to adding a turbo engine would be the total lack of hood clearance. The front lifting hook on the top of our engine rubs on the hood as it sits stock, so how would you install the crossover piping needed to add the turbo? Also the higher HP 855 motors all used some sort of inter-cooler in front of the radiator, which would require modifications to the front brush guard, the side headlight panels and maybe the winch setup if installed on the subject truck. MAYBE you could install the crossover pipe in front of the engine under the top radiator hose and cutoff the intake nozzle and re-weld it pointed towards the front. Would require a lot of forethought but could be done.

A few years ago, in the classified ads for MV Mag, there was a couple of "work" trucks in NJ for sale, one with a 350 and the other with a 290 so someone has done it.

 

[dma251]

The hood clearance problem isn't an issue. Having talked to two people that have done it you trim one of the front hood reinforcement ribs and optionally you put a rubber hood pad bolted to the front of the engine or somewhere near there to give it a little support if needed. You also have to remove the lifting eye I'm told. I'm not sweating the hood deal at all. My MV parts guy did it to his, and he has all the part numbers for a Cummins crossover pipe that works well. You also can keep the heater, you have to move it back closer to the firewall, however.

I know it works, but I am not familiar with this 335 cummins industrial motor. Anyone familiar? It's supposed to be th same as the NHC-250 but with a turbo and piston coolers.

Is it called a NTC-290?

 

[jatonka]

An NTC 290 is 290 horse power. It can be turned up to 335 very easily by adjusting the fuel button at rear of fuel pump. My NTC 290 does not have any extra cooler near radiator. I have a 3 stage Jake brake on mine. I am going to sell it, It needs an in frame kit to be like new. Has 371,000 original miles. jatonka

 

[dma251]

The piston coolers are spray nozzles that direct engine oil onto the bottoms of the pistons. I am told they are cast into the block and are impossible to retrofit to a regular 250 cummins. Apparently this is why you can turn the fuel up and not melt the pistons.

 

[WillWagner]

The piston cooling nozzles aren't cast into the block. Early ones were metal, later, 1980 and up, are nylon. Higher HP, 350 and above, engines have the places for the PC nozzles machined into them. The block casting is the same from a Piston cooled to a non piston cooled engine. Machining is the only difference, well, besides thin and thick deck. As for the cooler in front of the radiator, that's a Charge Air Cooler. Only introduced on Cummins engines in 1991 on the N-14. The engines prior to the N-14 used an air to water aftercooler. The dimensoins of all the small cam and big cam engines are the same. The only difference would be if you had a trunion mount, a steel ring machined onto the front cover, this extends the front apx 3 inches. The flywheel housing from a small cam will fit on a big cam with a small modification to the upper camshaft side bolt hole.(I still have a jig for this). This mount in the block was moved up and outward with the introduction of the big cam to make room for the cam. There is also an option for a low rise aftercooler, only sticks up around 2.5 - 3 inches above the valve cover. The inlet for the cooler is on the inboard side of the top housing. Ford used these on the L9000.

 

[jatonka]

Hi Will, Off Topic, your package is in the mail. PM me John T