Cummins B Series Engine

Overview

• Manufacturer: Cummins
• Production: Since 1984
• Applications: Multiple, including light-duty and medium-duty vehicles. Notably used in school buses, public service buses, and Dodge/Ram pickup trucks.
• Configurations: Inline-four (I4), Inline-six (I6)

Engine Specifications

• Displacement Options:
  • 3.9L (3,922cc)
  • 4.5L (4,460cc)
  • 5.9L (5,883cc)
  • 6.7L (6,690cc)
• Cylinder Bore:
  • 102mm
  • 107mm
• Piston Stroke:
  • 120mm
  • 124mm
• Materials: Cast iron for both cylinder block and head
• Valvetrain: Cam-in-block, 2 or 4 valves per cylinder
• Compression Ratios: Ranges from 17.2:1 to 19:1
• Fuel System: Common rail high-pressure direct injection
• Turbocharger: Holset Engineering (variable)
• Management: Bosch mechanical with electronic advance
• Output:
  • Power: 53 to 420 hp
  • Torque: 265 to 1,075 lb-ft

Emissions

• Emissions control systems include electronic fuel control, DPF, and EGR.

Engine Generations

• Three generations since introduction
• Offered in multiple displacements and configurations

Specific Models

3.9L

• 4B/4BT/4BTA
  • 4B: Naturally aspirated, 53hp, used in generators and wood chippers.
  • 4BT: Turbocharged, 105hp, common in commercial vehicles.
  • 4BTA: Turbocharged and aftercooled, 170hp, used in various applications.

5.9L

• 6B/6BT/6BTA/ISB
  • 6B: Naturally aspirated, no automotive applications.
  • 6BT: Turbocharged, used in 1989-1998 Dodge Ram, popular for fuel efficiency.
  • 6BTA: Turbocharged and aftercooled.
  • ISB: Introduced in 1998, used in light trucks and school buses, improved emissions control.

6.7L ISB

• Production: 2007-present
• Features:
  • Maximum Power: 420 hp
  • Torque: 610-1,075 lb-ft
  • Introduced Variable Geometry Turbocharger (VGT)
  • Used in Dodge Ram trucks, school buses, and other vehicles

Changes from 5.9L ISB to 6.7L ISB

• Larger displacement with increased bore and stroke
• Introduction of Variable Geometry Turbocharger (VGT) for reduced turbo lag

QSB Engine

• 5.9 QSB: Off-road version, used in marine, agricultural, and construction applications.

Fuel Systems

• Early Models: Mechanical injection with Bosch P7100 pump
• Later Models: Mechanical injection with electronic timing (Bosch VP44 pump)
• Recent Models: Electronically controlled common-rail injection

Notable Features

• Gear-drive camshaft for reliability
• Shallow one-piece head design
• Direct injection system, no glow plugs needed for cold starts
• Originally manufactured in Rocky Mount, NC, with additional plants in Mexico, Brazil, Turkey, and the UK.

References

• Several technical and historical resources provided.

This information provides a comprehensive overview of the Cummins B Series engine, its models, specifications, and applications. Useful for understanding its evolution and applications in various vehicles, especially for automotive and mechanical engineering studies.