290 cummins

[Csm Davis]

Have access to a 290 turbo cummins anyone know much good or bad thinking of using it for 816 repower

 

[Stalwart]

Not much power, I had one in a cabover with a 30' rollback bed a few years back. They are reliable but really could more fuel to make reasonable power. 30 years ago we had one in a dump truck and with a bigger turbo and more fuel it made easily in excess of 400 hp.

 

[Hooty481]

That engine is basically what you get when you add a turbo to a non turbo Nhc250. You will have a lot of good parts there even if you don't use it to repower. Granted it is not going to be a 400 by no means but it should pull the wrecker pretty good after you work with the fuel pump a little bit.

 

[Csm Davis]

Thanks guys that's what I was thinking, that other would be a little better at pulling the hills and might could be turned up fairly easy. Is it a 250 with a turbo or is it a different block?

 

[seano11]

nothing wrong with a 290 I'm sure you would be happy with it

 

[Bolkbich]

NHC 250 Doesnt have piston coolers so if you push it too far (fuel wise) it will score a piston. 270,290,300,335,350 etc have oil squirters that spray cooling oil on the bottom of the piston. you can turbo a 250 but the compression, timing, fuel timing ,cam etc is all different. Cummins dont like alot of fuel down low (below 1700 rpm) and they will blow head gaskets, so the 3-4 shift on a m809 can be really destructive with a load on (or just an empty M816). A 290 will handle the job worlds better than a 250 with a turbo. A 290 can be made into a 400 with no special parts. I had a 335 with 490 dynoed hp working everyday 36 lbs of boost 700-800 degrees on the pyro , a total sweetheart. Pittsburgh Diesel has everything you need to make a completely reliable animal.

 

[Vintage iron]

A Cummins NHC 250 and a Cummins NTC both use a 855 block. The 290 will be a step up for sure. What is it's running condition? how is it sitting now? Is it in a running truck or in a frame? You may want to check a few things before buying it.

Is it a small cam or big cam?
is it a really a 290?
is it a formula motor?
does it have piston squirters?
does it have Jacobs brakes?
does it have a block heater?
what does it use for starting assist?

All these things make a difference in price!

 

[Hooty481]

They are the same 855ci bock. I did forget to mention the piston coolers that bolkbich mentioned. There are several of us on this forum that are running the 250 with a turbo and haven't had any problems. I put a 290 pump on my truck and it runs great.

But back to the 290... A really good idea but you will have to do some modifications to the hood for the cross over pipe if you leave it stock. There are some pictures on here of trucks that have the 400 in that model of truck and they just put a hood scoope on the passenger side of the truck hood for clearance. Wasnt to pretty but would fit the military theme.

 

[Vintage iron]

I am getting ready to swap out my NHC 250 for a NTC 290 big cam with Jacobs brake, piston squirters, oil cooler and block heater. The motor has zero hours on it. It just needs a fresh coat of paint, new hoses and to change some parts over. I am planning on using the Jacobs brakes and the stock crossover. I will need to make 3" more inches of hood clearance to do this but it is worth it!

 

[Csm Davis]

Thanks guys few more questions how do I tell the difference between big and small cam or formula motor while it's still in the truck?

 

[Bolkbich]

the best way is get the #'s off the drivers side front of the engine

 

[Floridianson]

I have a 240 turbo waiting for a home and the harmonic balancer is larger. You might want to check the size and you might have to rework the front motor mount.

 

[hemichallenger]

Thanks guys few more questions how do I tell the difference between big and small cam or formula motor while it's still in the truck?

A formula motor runs at about 40 psi oil pressure. The block will say big cam on the drivers side and you can tell by the size of the cam followers.

 

[Vintage iron]

First of all. If the engine is on the truck I would want to drive it if possible or at least hear it run. Check the speedo for mileage too. The tag on the front left side will have all the information on the motor. I would take down all the info off the tag and call Cummins. They will be able to help you out! I would check the fluids. Check for oil in the anti-freeze or anti-freeeze in the oil.

 

[michigandon]

The Canucks had Jakes on their 800-series 5 tons, with a "bump" in the hood to accommodate, so a hood modification to make Jakes and/or a turbo fit really isn't all that non-prototypical at all.

Note the bump in the hood of this, um, M817? Not sure if our Neighbors to the North use(d) the same model number designations or not: http://www.hankstruckpictures.com/p.../military/trucks/t17a-gagetown_aug_08_268.jpg

 

[Karl kostman]

We have a Freightliner cabover with a 290 in it, great reliable motor it had had the heads done around 600K miles and we had its first major done at just under a million miles, been a very good motor but loaded the poor old girl does not have a lot to spare!
KK

 

[WillWagner]

Formula just means it is a 1900 governed engine, for fleet fuel economy. The oil pressure is deemed by the system, DFC or FFC. It's been a bit, but IIRC DFC,( demand flow cooling v.s FFC, full flow cooling), has the OP regulated at 40 PSI hot, rated RPM, that might be backwards, like I said, it's been a bit since I had to tell the difference between the two. The NH and NT will have the exact cxame mounting...unless the NT is a trunion mount.

 

[ODdave]

Dosnt the formula have a cast crank as well? To save on rotating weight?

 

[WillWagner]

They are all cast

 

[ODdave]

I thought the others where forged??? n14 cast?