290 cummins

[WillWagner]

What I'm saying is for the 855, there is one crank. The N14 is different, some counter weights have been removed and the rod journals are larger.

 

[Csm Davis]

Ok motor is in paystar dump that I am scrapping can't read all of tag, truck was wrecked on that side.

 

[11Echo]

I made a living for a while running a 290 many years ago. Good truck, good motor, reliable. I hauled steel, oversized equipment, and also pulled a dump trailer with it. The 13 speed Roadranger was a favorite transmission in those days.
This pic was after I just dropped an oversized load where I grossed 126k . I also pulled a pair of 30 ton mixers up to the same place. Truck moved the loads ok!

The 5 ton Canadian truck pic I took while at Adelman's.

 

[Csm Davis]

Not that I really need it but it has a JAKE Brake! Cool

 

[Floridianson]

NHC 250 Doesnt have piston coolers so if you push it too far (fuel wise) it will score a piston.

The main thing I hear is don't idle them long without piston oilers at higher speeds the splash from the crank is all over the crankcase.

 

[Vintage iron]

I am confused about floridainson's post. Can you explain that last post with more detail?

 

[WillWagner]

The cooling nozzles are there to help keep the piston temps down when the engine is loaded. Too much fuel, fueling beyond the design limits of the engine, causes more heat than the engine components were designed to take. When a turbo is added to the engine, you add heat to the cylinder. When you add more fuel to the cylinder, you add heat. The pistons are aluminum. The liners are cast iron. The only support on the liner is at the counterbore...the top of the liner, and toward the bottom, about 3 inches up from the bottom of the liner where the seal and o-rings are. The middle of the liner can expand, the top and seal area can't, the block is right behind it. When too much heat is added...turbo and or fuel, the piston expands and the middle section of the liner expands, it's supposed to do this, it is designed this way. The problem happens when the heat generated in the combustion process isn't or can't be removed/stabilized, that's why the cooling nozzles are there. A piston is smaller at the crown than at the skirt, this is designed this way because the combustion process makes heat and therefore expands the crown faster than the skirt. If the heat continues down the skirt, it expands too much. Remember the seal area on the liner that can't expand 'cause the lower receiver of the block is right behind it? Well, a skirt that expands too much won't fit through that hole very easily, the oil film on the piston....that's what all those little grooves are for running horizontally around the skirt on a piston...is lost and you have metal to metal contact. The soft aluminum sticks to the cast iron and it starts from there. More and more aluminum sticks to the liner, the hole gets smaller, less and less oil film, and before you know it, knock, knock, knock, high blowby...'cause the departing aluminum is working it's way toward the top of the liner as it's peeled off and is now in the ring travel area...the piston starts flopping around, skirts get knocked off, turns sideways, takes out the liner, tries to use the block as a cylinder, but that doesn't work, the load of the vehicle going down the road keeps the engine turning, rods get bent up like pretzels and the engine is ventilated.

That's why you need piston cooling nozzles in an engine making H/P and being loaded. The NHC will do fine with turning up the fuel a bit just driving around with the wt of the vehicle. If you are gona pull 40k with it, my advice is to leave it alone and enjoy the ride.

The nozzles have nothing to do with idling the engine and, the above happens in the blink of an eye. I have been in the vehicle driving down the road and had multiple vehicles on the dyno do this...no worst case like above happened, I caught it in time except for the on road one, I was just on a ride along.

 

[Floridianson]

Was just looking over an old thread and Will I will not argue the fact that the higher hp need piston skirt oilers. I just was trying to point out that the stock 250 without oilers acording to my injector man was just don't idle them too long.

 

[ludgy]

did you end up repowering with the 290 cummins?

i am in the process with a m880 and have run into a few problems, main being
-oil filter/cooler clearance issues (trying to source a remote filter setup)

 

[Csm Davis]

did you end up repowering with the 290 cummins?

i am in the process with a m880 and have run into a few problems, main being
-oil filter/cooler clearance issues (trying to source a remote filter setup)

You are putting a 290 cummins in a dodge?

 

[ludgy]

sorry i mixed up my trucks, m818

 

[Vintage iron]

I am putting my 290 in before Sussex show in April.