Cummins QSB6.7 Diesel Engine

Cummins QSB6.7 Diesel Engine

The Cummins QSB6.7 is one of the most versatile and trusted mid-range marine engines available today. Built on Cummins’ proven 6.7-litre, 6-cylinder platform, it delivers clean, responsive power in the 250–550 hp range and is widely chosen for both commercial vessels and high-performance leisure craft. With high-pressure common-rail fuel injection, turbocharging and seawater aftercooling, the QSB6.7 offers excellent fuel efficiency, low noise and class-leading reliability.

For repower projects, the QSB6.7 is especially attractive. Its footprint and service points make it a natural upgrade from the older QSB5.9 and similar engines, giving operators more power density with modern emissions compliance. Slimline configurations are available where space is limited, making it a strong choice for tight engine rooms and performance hulls.

Seapower Marine holds QSB6.7 engines and accessories in UK stock, with complete propulsion packages available immediately including gearboxes, controls, harnesses, mounts, exhaust components and cooling fittings. Each engine can be supplied with full upfit, programming, documentation and load-tested commissioning.

Typical Applications – Cummins QSB6.7 Diesel Engine

Fast pilot boats
Windfarm support vessels
High-speed passenger craft
Performance motor yachts
Auxiliary power for blue-water sailing yachts
Commercial workboats requiring long duty cycles

Benefits at a Glance

Smooth, quiet operation with low smoke and vibration
High efficiency and reduced fuel consumption
Compact options including slimline variants
Multiple rating choices for leisure and heavy-duty commercial use
Compatible with a wide range of ZF and Twindisc gearboxes
Industry-leading global support from Cummins’ service networ

Cummins QSB6.7 Diesel Engine The Cummins QSB6.7 (Quantum System B) diesel engine is one of the world’s most popular, robust, and versatile mid-range inline 6-cylinder engines. This 6.7-liter engine is designed for heavy-duty applications in maritime, construction, agriculture, and industrial generators.

Key Technical Specifications

Design Configuration: Inline 6-Cylinder, 4-Stroke

Displacement: 6.7 Liters (408 in)

Bore x Stroke: 107 mm (124)

Aspiration System: Turbocharged & Aftercooled / Intercooled

Fuel System: Bosch High-Pressure Common Rail (HPCR)

Power Range: 133–550 HP (99–410 kW), depending on application