1-5. PREPARATION FOR STORAGE AND SHIPMENT
Information concerning storage or shipment of equipment can be found in TM 740-90-1. Additional information concerning storage of
Cummins NTC-400 engine can be found in Chapter 3, Maintenance.
1-6. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIRs)
You can help improve this manual. If you find any mistakes or if you know of a way to improve the procedures, please let us know.
You may mail, fax or email your letter, DA Form 2028, or DA Form 2028-2 direct to: Commander, U.S. Army Tank-automotive and
Armaments Command, ATTN: AMSTA-LC-CIP-WT, Rock Island, IL 61299-7630. The email address is TACOM-TECH-
PUBS@ria.armv.mil. The fax number is DSN 793-0726 or Commercial (309) 782-0726.
1-7. WARRANTY INFORMATION
The Cummins diesel engine (model NTC-400) is warranted in accordance with TB 9-2300-295-15/21. The warranty starts on the date
found in block 23, DA Form 2408-9, in logbook. Report all defects in material or workmanship to your supervisor, who will take
Section II. EQUIPMENT DESCRIPTION AND DATA
1-8. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES
'"M9151Big Cam I" is intended and will be written hereafter to mean M915 through M920
series and M915A4 trucks with Big Cam I engines.
The Cummins NTC-400 diesel engine is used on all M915 through M920, M915A1, and M915A4 trucks. It is a turbocharged,
liquid-cooled, overhead valve, four-cycle engine of in-line six-cylinder design. The NTC-400 engine has a compression ratio of 13.5: 1
(M915) and 14.0: 1 (M915A1), and develops 400 horsepower at 2100 rpm. Peak torque is 1150 lb-ft at 1500 rpm (M915) and
1300 lb-ft at 1300 rpm (M915A1).
The following engine characteristics and features apply to both M915/Big Cam I and M915A1/Big Cam III engines, except
where differences are noted.
Camshaft: 2-1/2-inch diameter camshaft with gear drive controlling all valve and injector movement. Made of induction-
hardened alloy steel. Camshaft followers are roller type.
Connecting Rods: Drop-forged, rifle-drilled for pressure lubrication.
Crankshaft: High-tensile steel forging. Bearing journals and fillets-induction hardened. Fully counterweighted.
Cylinder Block: Alloy cast iron with removable wet liners.
Cylinder Heads: Each head serves two cylinders. Drilled fuel supply and return lines. High temperature inserts on exhaust
Turbocharger: Model T-50 (M915/Big Cam I); Model T-46-B, which has a redesigned compressor wheel, compressor
housing, turbine wheel and shaft, bearing housing assembly, location of oil inlet line, and vee bands (M915A1/Big Cam III).
Exhaust Manifold: Conventional log-type (M915/Big Cam I). Pulse-type for less restriction (M915A1/Big Cam III).
Fuel System: Integral flywheel-type governor.
Injectors: Camshaft actuated top-stop type.