Cummins QSB Series Marine Engine Parts & Spares
Alfa Marine Spare Parts supplies Cummins QSB Series marine engine parts and spares for commercial vessels, workboats, fishing vessels, patrol craft, passenger vessels, yachts, auxiliary engines and other marine applications.
Our Cummins QSB parts sourcing covers important engine configurations including the Cummins QSB5.9, QSB6.7 and QSB7, with components for scheduled maintenance, engine repair, fuel-system service, top-end overhaul and major engine rebuild requirements.
Depending on engine configuration and availability, we can source genuine, OEM, replacement and selected remanufactured Cummins QSB parts, including fuel injectors, high-pressure fuel-system components, cylinder heads, pistons, bearings, turbochargers, charge-air cooling components, sea water pumps, freshwater pumps, heat exchanger components, oil pumps, electronic sensors, gaskets, seals and overhaul components.
For individual engine requirements, visit:
Cummins QSB5.9 Marine Engine Parts
Cummins QSB6.7 Marine Engine Parts
For other Cummins engines, browse our Cummins Marine Engine Parts catalogue.
For correct parts identification, provide the complete engine model, Engine Serial Number (ESN), CPL where applicable and existing part number whenever available.
Need a specific component? Request a Quote or email request@alfamarinespareparts.com.
Cummins QSB Series Marine Engine Overview
The Cummins QSB Series represents an electronically controlled generation of compact Cummins diesel engines used in marine propulsion and auxiliary applications.
Important marine configurations include:
Cummins QSB5.9
Cummins QSB6.7
Cummins QSB7
The QSB5.9 uses an approximately 5.9-litre inline six-cylinder architecture, while the later QSB6.7/QSB7 platform uses approximately 6.7 litres of displacement.
These engines combine turbocharging, charge-air cooling, electronic engine management and high-pressure fuel-system technology.
Compared with older mechanically controlled Cummins B Series engines, QSB engines introduce additional electronic and fuel-system components such as:
- Electronic engine controls
- High-pressure fuel components
- Electronic fuel injectors
- Fuel-pressure sensors
- Engine sensors
- Wiring harnesses
- Electronic control components
This makes accurate engine identification particularly important when ordering QSB replacement parts.
Cummins QSB Series Marine Engine ModelsCummins QSB5.9
The Cummins QSB5.9 is an electronically controlled inline six-cylinder diesel engine with approximately 5.9 litres of displacement.
It represents an important development from the earlier mechanical 5.9-litre Cummins engine platform.
The QSB5.9 combines electronic engine management with turbocharging and charge-air cooling for marine propulsion and auxiliary applications.
Common parts requirements can include:
- Fuel injectors
- High-pressure fuel components
- Fuel pumps
- Fuel-pressure components
- Cylinder heads
- Pistons
- Piston rings
- Bearings
- Turbochargers
- Charge-air cooling components
- Sea water pumps
- Freshwater pumps
- Heat exchangers
- Oil coolers
- Oil pumps
- Sensors
- Electrical components
- Gaskets
- Seals
- Overhaul components
For detailed information, visit our Cummins QSB5.9 Marine Engine Parts page.
Cummins QSB6.7
The Cummins QSB6.7 is a later-generation QSB marine engine based around an approximately 6.7-litre inline six-cylinder configuration.
The engine uses electronic engine management, turbocharging, charge-air cooling and a high-pressure common-rail fuel system.
Parts requirements can include:
- Common-rail fuel injectors
- High-pressure fuel pumps
- Fuel-rail components
- Fuel-pressure sensors
- Cylinder heads
- Pistons
- Connecting rods
- Bearings
- Turbochargers
- Charge-air cooling components
- Sea water pumps
- Freshwater pumps
- Heat exchanger components
- Oil coolers
- Oil pumps
- Engine sensors
- Wiring harnesses
- Electronic controls
- Gaskets
- Seals
- Overhaul components
For detailed information, visit our Cummins QSB6.7 Marine Engine Parts page.
Cummins QSB7
The Cummins QSB7 designation is associated with the modern 6.7-litre QSB marine platform.
Depending on market, application and product documentation, customers may encounter references to both QSB6.7 and QSB7.
This makes it important to provide the complete engine identification rather than relying only on the general QSB7 description.
Potential parts requirements can include:
- Fuel injectors
- High-pressure fuel pumps
- Common-rail components
- Fuel-pressure sensors
- Turbochargers
- Charge-air components
- Cylinder-head components
- Pistons
- Bearings
- Cooling-system components
- Sea water pumps
- Oil-system components
- Sensors
- Electronic controls
- Wiring components
- Gaskets
- Seals
For QSB7 requirements, provide the complete engine designation and ESN so the correct configuration can be identified.
Cummins QSB Series Technical SpecificationsSpecificationQSB5.9QSB6.7 / QSB7ManufacturerCumminsCumminsEngine familyQSBQSBEngine type4-stroke diesel4-stroke dieselConfigurationInline 6-cylinderInline 6-cylinderDisplacementApprox. 5.9 LApprox. 6.7 LBoreApprox. 102 mmApprox. 107 mmStrokeApprox. 120 mmApprox. 124 mmAspirationTurbochargedTurbochargedCharge-air systemCharge-air cooledCharge-air cooledEngine controlElectronicElectronicFuel systemHigh-pressure electronic fuel injectionHigh-pressure common railCoolingLiquid cooled / marine configuration dependentLiquid cooled / marine configuration dependentApplicationsMarine propulsion / auxiliaryMarine propulsion / auxiliary
Exact specifications, ratings, emissions configurations and installed equipment vary according to the individual engine.
Cummins QSB Series Fuel System Parts
The fuel system is one of the most important areas where QSB engines differ from older mechanically controlled Cummins engines.
Depending on QSB generation and configuration, fuel-system requirements can include:
- Fuel injectors
- High-pressure fuel pumps
- Fuel rails
- Fuel-pressure sensors
- Fuel-pressure regulators
- Fuel supply pumps
- Fuel filters
- Fuel-water separator components
- Fuel lines
- Fuel fittings
- Electronic fuel controls
- Seals
- O-rings
- Gaskets
Fuel-system components should always be identified using the individual engine information.
For accurate sourcing, provide:
Engine Model + ESN + Existing Fuel-System Part NumberCummins QSB Fuel Injectors
Fuel injectors are among the most frequently requested QSB engine components.
Requirements can include:
- Complete fuel injectors
- Injector sealing components
- Injector O-rings
- Injector installation components
- Associated high-pressure fuel parts
QSB5.9 and QSB6.7 injectors should not automatically be considered interchangeable.
Injector specification can also differ between engine ratings and production revisions.
When requesting injectors, provide:
Engine model: QSB5.9 / QSB6.7 / QSB7
Engine Serial Number:
Existing injector number:
Quantity:
Cummins QSB High-Pressure Fuel Pump Parts
Depending on engine generation and fuel-system configuration, requirements can include:
- Complete high-pressure fuel pumps
- Pump components
- Fuel supply components
- Pressure-control components
- Fuel-pressure sensors
- Fuel lines
- Drive components
- Gaskets
- O-rings
- Seals
For high-pressure fuel-system components, the ESN and existing component number are particularly important.
Cummins QSB Cylinder Head Parts
Cylinder-head requirements can include:
- Complete cylinder heads
- Intake valves
- Exhaust valves
- Valve guides
- Valve seats
- Valve springs
- Rocker components
- Push rods
- Valve-train components
- Cylinder-head gaskets
- Valve-cover gaskets
- Injector installation components
- Seals
- Related hardware
QSB5.9 and QSB6.7 cylinder-head components should be identified separately.
Cummins QSB Pistons & Internal Engine Parts
Internal-engine requirements can include:
- Pistons
- Piston rings
- Piston pins
- Connecting rods
- Connecting-rod bushings
- Main bearings
- Connecting-rod bearings
- Thrust components
- Crankshafts
- Camshafts
- Timing components
- Gaskets
- O-rings
- Seals
Major internal components should always be matched to the individual engine configuration.
For overhaul requirements, provide the ESN before selecting pistons, bearings and related internal components.
Cummins QSB Turbocharger Parts
QSB marine engines use turbocharging to achieve strong power output from their relatively compact engine displacement.
Turbocharger requirements can include:
- Complete turbochargers
- Turbocharger cartridges
- Compressor components
- Turbine components
- Shafts
- Bearings
- Seals
- Oil-feed components
- Oil-return components
- Intake connections
- Exhaust connections
- Mounting gaskets
Turbocharger specifications can differ according to engine rating.
Provide the existing turbocharger identification number whenever available.
Cummins QSB Charge-Air Cooling Parts
QSB engines use charge-air cooling as part of the air-management system.
Requirements can include:
- Charge-air cooler assemblies
- Cooler cores
- Covers
- Intake pipes
- Air connections
- Cooling connections
- Hoses
- Clamps
- Gaskets
- O-rings
- Seals
- Mounting components
The QSB5.9 and QSB6.7/QSB7 platforms can use different charge-air system components.
Cummins QSB Marine Cooling Parts
Marine cooling-system requirements can include:
- Sea water pumps
- Raw-water pumps
- Freshwater pumps
- Jacket-water pumps
- Heat exchangers
- Oil coolers
- Charge-air cooler components
- Thermostats
- Thermostat housings
- Cooling pipes
- Hoses
- Mechanical seals
- Gaskets
- O-rings
Cooling arrangements can differ according to engine rating, marine installation and vessel configuration.
Cummins QSB Sea Water Pump Parts
Applicable marine installations can require:
- Complete sea water pumps
- Raw-water pumps
- Pump housings
- Pump shafts
- Impellers
- Bearings
- Mechanical seals
- Covers
- Gaskets
- O-rings
- Repair components
If the existing pump number cannot be identified, send photographs of the pump together with the engine ESN.
Cummins QSB Freshwater Pump Parts
Freshwater or engine-coolant pump requirements can include:
- Complete water pumps
- Pump housings
- Impellers
- Shafts
- Bearings
- Mechanical seals
- Gaskets
- O-rings
- Repair components
Correct pump identification should be based on the exact QSB engine configuration.
Cummins QSB Heat Exchanger Parts
Marine QSB installations can use heat exchangers as part of the engine cooling system.
Requirements can include:
- Complete heat exchangers
- Heat exchanger cores
- End covers
- End caps
- Gaskets
- O-rings
- Seals
- Cooling connections
- Mounting components
For older vessels, the installed heat exchanger may have been replaced or modified during previous repairs.
Existing part numbers and photographs can therefore assist with identification.
Cummins QSB Lubrication Parts
Lubrication-system requirements can include:
- Engine oil pumps
- Oil filters
- Oil coolers
- Oil-pressure regulators
- Oil-pressure sensors
- Oil lines
- Oil-pan components
- Crankshaft seals
- Gaskets
- O-rings
Correct lubrication components should be selected according to the individual engine.
Cummins QSB Sensors & Electronic Parts
Electronic engine management is a major feature of the QSB family.
Depending on engine generation and configuration, requirements can include:
- Engine speed sensors
- Temperature sensors
- Pressure sensors
- Fuel-pressure sensors
- Oil-pressure sensors
- Coolant-temperature sensors
- Intake-pressure sensors
- Wiring harnesses
- Electrical connectors
- Engine control components
- Displays and monitoring components
Electronic components can be highly configuration-sensitive.
Always provide the ESN and existing component number.
Cummins QSB Starter & Alternator Parts
Starting and charging-system requirements can include:
- Starter motors
- Starter solenoids
- Alternators
- Charging-system components
- Electrical cables
- Relays
- Sensors
- Switches
- Connectors
Before ordering, verify:
- Engine model
- ESN
- System voltage
- Existing starter or alternator number
Cummins QSB Gaskets & Seals
Gasket and sealing requirements can include:
- Cylinder-head gaskets
- Valve-cover gaskets
- Intake-manifold gaskets
- Exhaust-manifold gaskets
- Turbocharger gaskets
- Charge-air cooler gaskets
- Oil-pan gaskets
- Water-pump gaskets
- Crankshaft seals
- Fuel-system seals
- Injector seals
- O-rings
- Complete gasket sets
Complete gasket requirements can also be prepared together with overhaul components.
Cummins QSB Series Overhaul Parts
For a Cummins QSB engine overhaul, Alfa Marine Spare Parts can assist with applicable:
- Pistons
- Piston rings
- Piston pins
- Main bearings
- Connecting-rod bearings
- Connecting rods
- Cylinder-head components
- Intake valves
- Exhaust valves
- Fuel injectors
- High-pressure fuel components
- Turbocharger components
- Charge-air cooler components
- Water pumps
- Oil pumps
- Oil cooler components
- Sensors
- Gaskets
- O-rings
- Seals
The exact overhaul requirement should always be prepared according to the engine model and ESN.
Cummins QSB Top-End Overhaul Parts
Top-end requirements can include:
- Cylinder heads
- Intake valves
- Exhaust valves
- Valve guides
- Valve seats
- Valve springs
- Rocker components
- Push rods
- Fuel injectors
- Injector seals
- Cylinder-head gaskets
- Valve-cover gaskets
- O-rings
- Seals
For a complete top-end requirement, provide the engine identification information and quantities required.
Cummins QSB5.9 vs QSB6.7
The QSB5.9 and QSB6.7 belong to the same wider QSB family, but they are different engine platforms.
The QSB5.9 has approximately 5.9 litres of displacement.
The QSB6.7 has approximately 6.7 litres of displacement.
Differences can affect:
- Fuel injectors
- High-pressure fuel-system components
- Fuel pumps
- Cylinder heads
- Pistons
- Connecting rods
- Crankshaft components
- Turbochargers
- Charge-air cooling components
- Cooling-system parts
- Oil-system components
- Sensors
- Electronic controls
- Wiring harnesses
- Gaskets
- Marine accessories
Parts should therefore never be selected simply because both engines carry the QSB designation.
For individual engines, visit:
Cummins QSB5.9 Marine Engine Parts
Cummins QSB6.7 Marine Engine Parts
Cummins QSB6.7 and QSB7
The QSB6.7 and QSB7 designations relate to the modern 6.7-litre QSB platform, but the complete engine identification remains important.
Customers may encounter QSB6.7 or QSB7 terminology depending on engine generation, market, rating and documentation.
When requesting parts, do not rely only on the QSB7 name.
Provide:
- Complete engine designation
- Engine Serial Number
- Existing part number
- Component identification number
- Clear photographs where necessary
This allows the individual engine configuration to be identified more accurately.
Cummins QSB Series Marine Applications
Depending on engine model, rating and configuration, QSB marine engines can be found in applications including:
- Commercial workboats
- Fishing vessels
- Patrol boats
- Pilot boats
- Crew boats
- Passenger vessels
- Rescue craft
- Small ferries
- Recreational vessels
- Yachts
- Marine auxiliary installations
The engine rating and installed equipment should always be verified against the individual engine.
Cummins QSB Engine Identification
Correct identification is particularly important for QSB engines because electronic controls, fuel-system components and other equipment can differ according to production generation and engine rating.
When requesting parts, provide:
Engine family: Cummins QSB
Engine model: QSB5.9 / QSB6.7 / QSB7
Engine Serial Number (ESN):
CPL where applicable:
Existing part number:
Part description:
Quantity:
For fuel injectors, high-pressure pumps, turbochargers, sea water pumps, sensors, electronic controls, starters and alternators, photographs of the existing component can also assist.
The preferred identification sequence is:
Engine Model + ESN + Existing Part NumberWhy Source Cummins QSB Parts From Alfa Marine Spare Parts?
Alfa Marine Spare Parts supports shipowners, vessel operators, ship managers, shipyards, marine engineers, purchasing departments, repair companies and engine rebuilders with Cummins QSB Series marine engine parts and spares.
Depending on availability, we can assist with:
- Routine maintenance parts
- Fuel injectors
- High-pressure fuel pumps
- Fuel-system components
- Cylinder heads
- Pistons
- Bearings
- Internal engine components
- Crankshaft components
- Turbochargers
- Charge-air cooling components
- Sea water pumps
- Freshwater pumps
- Heat exchanger components
- Oil pumps
- Oil cooler components
- Engine sensors
- Electrical components
- Starter motors
- Alternators
- Gaskets and seals
- Top-end overhaul parts
- Complete overhaul requirements
- Genuine parts
- OEM parts
- Replacement parts
- Selected remanufactured components
For individual engine requirements, visit our Cummins QSB5.9 Marine Engine Parts and Cummins QSB6.7 Marine Engine Parts pages.
You can also browse our Cummins B Series Marine Engine Parts, Cummins C Series Marine Engine Parts, Cummins 855 Series Marine Engine Parts and Cummins Marine Engine Parts catalogue.
Alfa Marine Spare Parts is an independent marine spare-parts supplier and is not an official Cummins dealer.
Frequently Asked QuestionsWhat Is the Cummins QSB Series?
The Cummins QSB Series is a family of electronically controlled inline six-cylinder diesel engines used in marine propulsion and auxiliary applications.
Which Cummins QSB Engines Are Covered?
Our QSB family coverage includes QSB5.9, QSB6.7 and QSB7 requirements.
What Is the Cummins QSB5.9 Engine Size?
The QSB5.9 uses approximately 5.9 litres of displacement.
What Is the Cummins QSB6.7 Engine Size?
The QSB6.7 uses approximately 6.7 litres of displacement.
Is QSB6.7 the Same as QSB5.9?
No. Although both belong to the QSB family, they use different displacement and component configurations.
Is QSB7 Related to QSB6.7?
Yes. The QSB7 designation is associated with the modern 6.7-litre QSB platform. Exact engine identification should still be used when sourcing parts.
Does the Cummins QSB6.7 Use Common-Rail Fuel Injection?
Yes. The QSB6.7 uses electronically controlled high-pressure common-rail fuel injection.
Can You Supply Cummins QSB Fuel Injectors?
Yes. Depending on configuration and availability, we can assist with applicable QSB fuel injectors and associated fuel-system components.
Can You Supply Cummins QSB High-Pressure Fuel Pumps?
Yes. Provide the engine model, ESN and existing fuel-pump number whenever possible.
Can You Supply Cummins QSB Turbochargers?
Yes. We can assist with applicable turbochargers and associated components. Provide the existing turbocharger identification number for accurate matching.
Can You Supply Cummins QSB Sea Water Pumps?
Yes. We can assist with applicable sea water pumps and other marine cooling-system components.
Can You Supply Cummins QSB Electronic Parts?
Yes. Depending on availability and engine configuration, we can assist with applicable sensors, wiring components, electronic controls and related engine electrical parts.
Can You Supply Cummins QSB Overhaul Parts?
Yes. We can assist with applicable pistons, bearings, cylinder-head components, fuel-system parts, turbocharger components, pumps, gaskets, seals and other overhaul requirements.
Related Cummins Marine Engine Pages
Cummins QSB5.9 Marine Engine Parts
Cummins QSB6.7 Marine Engine Parts
Cummins B Series Marine Engine Parts
Cummins C Series Marine Engine Parts
Cummins 855 Series Marine Engine Parts
Cummins QSC8.3 Marine Engine Parts
Cummins QSL9 Marine Engine Parts
Cummins QSM11 Marine Engine Parts
Request Cummins QSB Series Marine Engine Parts
Looking for Cummins QSB Series marine engine parts, maintenance spares or overhaul components?
Send us:
Engine model: QSB5.9 / QSB6.7 / QSB7
Engine Serial Number (ESN):
CPL where applicable:
Existing part number:
Part description:
Quantity:
Required condition: Genuine / OEM / Replacement / Remanufactured
Delivery destination:
Required date:
If the part number is unknown, include clear photographs of the engine identification plate and existing component.
Email: request@alfamarinespareparts.com
You can also browse our Cummins Marine Engine Parts catalogue.
Worldwide supply of Cummins QSB Series parts for commercial vessels, workboats, fishing vessels, yachts, shipyards, marine repair companies and engine rebuilders.