Question for the NHC cummins experts

[162tcat]

I have a cummins 335 small cam engine that I'm going to pull the turbo, intake and exhaust from and install it on my NHC250. Can the piston oil squirters be removed from the 335 and add them to the NHC250?

I'm not looking to make a hot rod, just a little more power and clean up the smoke.

I don't want to swap engines because I don't really have the equipment to do that and the 335 is high mileage though it still runs great.

Thanks in advance!

 

[doghead]

Nope.

 

[162tcat]

So what your saying is the small cam 335 block is different from the small cam 250 block? I understand that the big cam and small cam blocks were very different, I would have thought all SC blocks would be cast the same though.

 

[Gamagoat1]

NHC 250 has no "oil squirters", or any place to install them.

 

[tobyS]

Is oil cooling on the pistons a requirement of the 250 when one wants a turbo? Can NHC 250 ever be made into a high performer? I thought balance, given the length of stroke, is a primary issue in rpm for that engine and even to a lesser degree, the 8.3.

 

[doghead]

They are not machined for the oilers.

 

[Ferroequinologist]

I know you said you didn't want to do the swap, but the easiest, fastest way to get what you want is to swap the entire engine. This way, you have an engine will all the appliances and additions that engineers and designers build to work together from the factory and it will last longer, with no fitting or cutting or attempt 12 at something to get it to fit and work. The 250 was designed and built to produce what it produces. Once you start modifying it it will be operating outside of the design specs. Can it be done? yes. Will it last? so far others engines have held up. It is not plug and play as an engine swap would be however.

But just because you can modify a dryer to wash clothes and dry them, doesn't mean it is a good idea.

 

[wreckerman893]

Can NHC 250 ever be made into a high performer?

You can't gold plate a turd (well you can but then you just have an expensive turd).

They are an old school engine built to pull but not run with the big dogs.

That may be why the military never added a turbo to the 5 tons like they did to the deuces.

 

[papabear]

You can't gold plate a turd (well you can but then you just have an expensive turd).
They are an old school engine built to pull but not run with the big dogs.
That may be why the military never added a turbo to the 5 tons like they did to the deuces.

And WHATEVER you do...don't try running paint thinner in a cummins 250. Right WM??

 

[wreckerman893]

And WHATEVER you do...don't try running paint thinner in a cummins 250. Right WM??

I deny everything and demand proof.

 

[patracy]

I will buck the current norm of replies here.

You can install the turbo setup onto the NHC 250, there's been a number of members here that have done it. HOWEVER, it should be done with caution. We've already broached the oil squirter issue. But also you need to consider a few other things as well. The fuel can be turned up, but not much. You can also swap buttons to increase the timing on the engine. You can also do a dual feed line setup. You will always be limited by what the NHC is though. A NA engine. So any performance gains will need to be VERY conservative. Another issue to address is the ports in the heads that flow from the rocker boxes to the intake ports. Some have drilled, tapped, and installed bolts to plug these off.

Realistically, you can add a turbo to a NHC and drive it till the cows come home. But, it'll only make about 275-300hp tops and still be safe.

FWIW, I have a big cam exhaust manifold and a HT3B turbo that I'll be swapping onto my engine in the future. I've already done the dual feed setup (and noted a little power gain). Yes, it's a lot of work and money for less than 50hp in my case. But I'm not wanting to endure the cost of an engine replacement.

 

[crewcab454]

i am very pleased with the performance gains. i installed an ht3b and big cam manifold on my 250. i also installed a boost a pyro gauge. i am still playing with the pump buttons but as of now it has a #5 in it.