Below is something I found online (I can't remember where). May be of interest here.
-----Original Message-----
From:
Powermaster@cummins.com [mailto
owermaster@cummins.com]
Sent: Tuesday, August 19, 2003 2:03 PM
To: xxxxxxxxxxxxx.com
Subject: Re: RQST00000169662 - NHC 250 engine manual
Summary: NHC 250 engine manual
Solution:
Thanks for your Email message.
The Cummins NH250 engine is 855 c.i.d. small (2 in.) camshaft engine rated
250 hp @ 2100 rpm with 654 lb-ft torque @ 1500 rpm and clutch engagement
torque at 600 lb-ft @ 800 rpm. The engine weighs 2500 lbs. and is naturally
aspirated with a 6 gal lube system. The engine is still in production
mostly for military applications and there should be no problems finding
replacement parts for this engine model.
In the NHC250 era, some applications needed a way to supply more air to the
engine to help eliminate black smoke problems, especially in higher
altitudes and Cummins developed a turbocharger 'smoke kit'. The kit included
all the components required to install the turbocharger on the engine, as
well as information about required changes to the fuel pump and injector
settings that increased engine horsepower from 250 to 270 hp. Some Cummins
distributors may still have the Service/Parts Topic that provides the
details of the 'smoke kit'.
According to Cummins Service/Parts Topic 73T10-1 dated January 1973, Cummins
Service/Parts Topic 72T18-1 dated June 1972 contains comprehensive details
of ratings, fuel pump codes and specifications/part number of the
significant components of all recent NH and NT models. These topics indicate
that naturally aspirated engines should be derated 3 % for each 1000 feet in
altitude.
We also have a more current bulletin no. 3379020-00 dated April 1975 titled:
NH220/230 and NHC250 Turbocharger Conversion Kits. This bulletin has
comprehensive part numbers, instructions and information about components
and changes required to install the turbocharger smoke kits on these engine
models. Your local Cummins distributor should have this bulletin in their
files and can determine if the parts are available or if current parts can
be used.
If the above topics are not available, then the Cummins distributor may want
to refer to Cummins parts catalog 3379590-00 dated March 1979. This parts
book covers the Cummins Small Cam NT-855 model engines for automotive
applications which includes NTC-250 and NHCT-270 engines.
Gannett Direct Marketing in Louisville, KY, handles all Cummins literature.
If a payment arrangement is worked out, by credit card, they can arrange
shipment of Cummins literature.
However, they deal in bulletin numbers, so before you call you need to have
all the bulletin numbers ready for the literature you need. You can reach
Gannett by calling 1-800-646-5609 or call 1-800-DIESELS and select the
literature option or email to
inquiry@gdms.com .