turbo on a NHC 250 Cummins?

[jh1990]

is it possiable to but a turbo on the Cummins motor that's in the most of the 5 tons? or will it turn out to be to much trouble for any gain that would be gained?
just inquiring, thanks.
Jason

 

[mangus580]

You can put one on..... but I have been told it doesnt clear the hood.

 

[WillWagner]

The crossover might be too tall to clear the hood.

 

[Towman2277]

Hey all, The crossover IS too tall to clear the hood, unless you install a sheet-metal "bubble" to clear.... Steve

 

[73m819]

ive been told by cummins wrench turners, that to make a cummins 250 into a cummins 290 (addind turbo), you have to change the cam to the big cam, we have the little, do a major injector pump retune, change the basic timming, and a few other things to make this work. plus add cooling. i was going to do this on my m819, as a side note, found out that a jake set up wont clear the hood at the front of the engine eather, so both projects got cut off at the pass, im still going to install a exhaust brake and i guess a 10 speed od to make better use of the power that i have, just my 2 cents worth

 

[WillWagner]

Can't change a small cam to a big cam. Big cam engine and small cam engine are two different animals. I guess you wouldn't necessarily have to do a fuel pump on it, if you don't mind alot of black smoke on accelereation! No timing changes. You can still put jakes on it, just use the rear 2 heads and leave the front off, Ford and Volvo have been doing that for years. Yes, you will only have 2/3 the braking power, but that is way bettter than using a potato brake. Ya know,there are two types of x-overs for a turboed, non aftercooled small cam, one is a steel pipe that makes a big sweeping bend into the intake and the other is aluminum that makes close to the same bend. The x-over for a big cam is flat, made of steel or aluminum and clears jakes if installed. You could make a plate to neck down the big hole in the intake for the small cam x-over and use the big cam x-over. BTW, if you add a turbo, use the Holset, not the T-46 or ST50

 

[jh1990]

Thanks for the info. guess that idea's trashed. how hard would it be just to swap the NHC 250 for a Big Cam Cummins? thanks again.

 

[WillWagner]

Dimensions are the same, maybe just the front mount, is it a trunion mount?, and the mount pad location on the flywheel hsg. The housing will work, but from small to big cam there is a modification to one of the bolt holes in the hsg, just gotta make it bigger to clear the cam plug. I have a jig if you need it.

 

[jh1990]

thanks but i don't think i need, i'm just wondering out of pure couristity, but thanks anyway. how hard would it be to put a bigger tranny in one?

 

[jh1990]

thanks, anyone have any idea why the military didn't put a turboed desiel in the 5 tons? thanks again.

 

[DDoyle]

Jason,
The NHC250 gave them all the power they wanted/that the driveline was designed for considering the conditions the vehicle is designed to operate in. The R6602, ENDT673, LDS465 and the NHC250 all have similar performance.

Best wishes,
David Doyle

 

[jh1990]

thnt makes sense, thanks to everyone for answering my questions or putting up with them, which ever comes first.

 

[jasonjc]

They did put a turbo on the 939A1/A2's

 

[G744]

The older Mack-powered (The A1- series) had turbos. They used the ENDT-673 Thermodyne engine and the 5-speed OD trans.

Not buiilt in any great quantity, most all were done by Kaiser Jeep Corp in 66 thru 68.

They pull well, and my old untuned-for-sport M54A1 will outrun any M809 cargo any day.

dg

 

[ken]

Instead of running a charge air tube across the top, could you put a intercooler infront and come up the drivers side with the tube?

 

[supermechanic]

Search thread "more power" Nov. 14, 2005

 

[jh1990]

ok will hopefully get around to it

 

[WillWagner]

There mihgt be an issue with too cool of intake air temp. The engine wasn't designed for that type of technology. Lots of white smoke happens, all of the time.

 

[Steamynachos]

On my M813A1 the Canadian military put a jake brake on the truck but found out that it dont fit under the hood so they had a Fab. tec. cut and put a box on the hood to clear the jake so on my truck there is large square bump on the hood of my truck but the jake works great and sounds even better

 

[MidnightDuramax]

Can some one tell me what turbo I should look for for my nhc 250 and what jake brake to use. I am just getting into these vehicles and would like to start customizing mine.