5.9 L 24-valve Cummins ISB

 

In 1998, the BT 5.9 was redesigned as a 24 valve engine to updated emission requirements. ISB stands for Interact System B. The ISB featured a Bosch VP44 rotary injection pump until 2003, when the injection system was upgraded to a Bosch high pressure common rail fuel injection system, which increased power output. In 2001, a high output (HO) version of the ISB became available, which slightly increased the ouput of manual transmission equipped trucks. A 610 version of the ISB became available which pushed torque to 610 lb-ft. Well known for its low speed torque, the Cummins 5.9 ISB has an advantage over V8 diesel engines in the light duty truck market.

5.9 L ISB Specifications:

 

Displacement:	359 cubic inches, 5.9 liters
Configuration:	Inline 6 cylinder
Compression Ratio:	16.3:1, 17.2:1 (high output version)
Bore:	4.02 inches
Stroke:	4.72 inches
Injection:	Direct Injection: Electronically controlled Bosch VP44 rotary injection pump. Bosch high pressure common rail injection introduced for 2003 model year.
Aspiration:	Holset turbocharger
Valvetrain:	OHV, 4 valves per cylinder, solid lifter camshaft
Oil Capacity:	10 quarts
Weight:	approx. 1,150 lbs
*Horsepower:	235 - 325 HP @ 2,900 RPM
*Torque:	460 - 610 lb-ft @ 1,600 RPM

*Varies with model year.

 

5.9 L Cummins Facts

• ISB is the acronym for Interact System B.
• The 5.9L ISB made Ward's 10 Best Engines list in 2004.
• Power output on automatic equipped Cummins powered Rams was slightly downrated from the manual transmission powered Rams from 1998 - 2001.