Specs for a 1998 Cummins Diesel Engine

In 1989, Dodge started the diesel war -- involving Dodge, Ford and General Motors -- with the joint venture it agreed to with Cummins to use their diesel engines in Ram trucks. In 1998, the Dodge Ram 2500 and 3500 had two optional Cummins diesel engines.

Internals

The two Cummins diesel options in 1998 were nearly identical on the inside. They both had a bore (cylinder width) of 4.02 inches, a stroke (distance piston travels inside the cylinder) of 4.72 inches and a total displacement of 359 cubic inches, or 5.9 liters. The only differences between the two was the compression ratio and valve train. The B 5.9-liter had a 17.0:1 ratio, while the ISB version had a 16.3:1 compression ratio. The B version had 12 valves and the ISB model had 24 valves.

Horsepower

The horsepower ratings varied slightly between the two versions of the engine. The B model, which was always used with an automatic transmission, produced 215 horsepower at 2,700 rpm. The ISB version -- always used with a manual transmission -- produced 235 horsepower at 2,700 rpm.

Torque

Just as the horsepower varied between the two models, so did the torque. The B model 1998 Cummins diesel produced 420 foot-pounds of torque at 1,600 rpm. The ISB model was significantly higher at 460 foot-pounds of torque at 1,600 rpm.

References

• Cummins Diesel Specs: Cummins Diesel Timeline
• Cummins Diesel Specs: ISB 5.9-Liter Cummins Diesel Specs
• Cummins Diesel Specs: B 5.9-Liter Cummins Diesel Specs