Greetings,
I have a old but fresh Cummins NHC 250, 855cui inline 6 with 12k miles. I want to add a turbo and was wondering if anybody is familar with these older motors and can lend me some info. I have seen it done but don't have any of the specifics as to what and how they figured out the proper turbo size. I am not looking for a motor eating hot rod just a little more power.
I find that the exhaust manifolds from the bigger motors bolt up. But how do I figure out what is the right size Turbo is the issue at hand?
Also my wife called in the Block #'s to Cummins(I'm deployed in Baghdad at the moment) and she was told that it was a 1981. I hear that there is a possibility that the late 250 blocks came with piston coolers which would mean that I could utilize more boost than say the 8-12 lbs range like the non cooled blocks.
Any info on this is greatly appreciated as I am hoping to research and aquire all the parts so I can make the upgrade when I return home in May. Thanks for all

 

which do you have?
big cam 2 , 3 or big cam 4

some 855 require a series set up

turbos that 855 used

t46b
t46
ht3b
bht3b

if you can give me the E.S.N I can find out what you need.

 

hey there Cummins guy, thanks for the response.
I have the nhc 250 it is a small cam. i am still trying to find out if it has the piston coolers. I hear that the later model 250 blocks might have had them. This seems to me that i would then be able to run a little more boost on her. I have spoke with a few guys that have done this on non p.cooled blocks and they can only make 8-10 lbs with out burning pistons. It gives the the boost they needed. I am serving in iraq right now so I am not able to tackle this head on. trying to get all the info and research as possible so i can make the mod in the spring when i return back home.

 

ive got this st-50 from an 855.Its a predecessor to the hx50.Its been proffessionally rebuilt and cleanedabsolute 0 shaft play.I could sell it if you want

 

If you can give me the seriale #, I can tell you anything you want to know about your engine.

 

greetings guys,
Cummins guy, when my wife gets back I will have her pull the #'s and post them.

Stillcummin, How much for the turbo and do you have a manifold for it too?
Thanks

 

no manifold 350 shipped

 

I have done the same thing that HOSSMAN is talking about doing. I have alreayd got mine together and running. My pump is leaking and I would like to order a pump that will be better for the truck than the factory 250 pump. Is there any way you could tell me what i would need to put on the truck.

Engine#11201821
S.O. NO.-24065
Family 091
CPL 0026
MFG:7/84
Timing Code E

this is all the information that i could get from the engine tag

thanks in advance.

 

I,VE RUN A SMALL CAM CUMMINS FOR WELL OVER A MILLION MILES, EXCELLENT ENGINES AND 99% OF THEM HAVE OIL COOLED PISTONS. ONLY THE VERY EARLY ONES DONT AND THEY CAM OUT AS 220HP MODELS. FROM THE LATE 60'S ON THEY HAD COOLERS. IDEALLY YOU WANT A 3801919 OR 3801918 BLOWER BUT THERE VERY EXPENSIVE EVEN IF YOU HAVE A CORE TO TRADE IN, THE NEXT BEST IS HT3B THEN T-46B . ALL THE 50 SERIES BLOWERS WAS EARLY TECHNOLOGY. ALL AFTER THAT WAS HOLESETS AND RESPOND TO THROTTLE ALOT BETTER. AND AS FAR AS FUEL PUMP IDEALLY YOU WANT A EARLY PUMP AS IT HAS NO SENCE OF BLOWER BOOST AND WILLGIVE YOU THE FUEL WHEN YOU ASK IT TOO. PUT A NUMBER 5 BUTTON IN THE PUMP AND ADD RPM SPRINGS TO 2350 RPMS MAX AND IT WILL DO YOU A FINE JOB "BUT" YOU MUST RUN A PYROMETER AND NEVER LET IT GET OVER 1100 DEGREES EXH TEMP IF YOU WANT LONG LIFE OUT OF IT. I HAVE A T46B FOR $150.00, A EARLY FUEL PUMP AND I THINK IT EVEN HAS THE TORQUE ARM ON IT FOR $150.00, A BOX FULL OF PUSHRODS $75.00, A BIG BOX OF NEW ENGINE GASKETS FOR $100.00 AND A COFFEE CAN FULL OF SMALL CAM JAKE BRAKE PARTS FOR $150.00 WILL MAKE A GREAT PACKAGE DEAL. I,AM A RETIRED OWNER OPERATOR TRUCKER AND RAN SMALL CAM CUMMINS IN ALL MY TRUCKS .
BOB

 

I'll give you the 350. I know my 5.9l can spool it hahaha maybe if I give it a year. That turbos massive.