Cummins/Onan QSB6.7 Engine
The Cummins/Onan QSB6.7 is a 6.7 L 6-cylinder turbocharged and charge-air cooled engine rated at 1470 rpm, producing up to 163 kW. It powers generator sets from Cummins/Onan and Komatsu, including the CFP7E-F10, CFP7E-F50, CFP7EVS-F10 and CFP7EVS-F50. It holds 14.2 L (3.8 gal) of oil and 14.2 L (3.8 gal) of coolant.
Also known as: Cummins QSB6.7
Part of the Cummins/Onan QSB6.7 engine family — 7 variants share parts & fitment.
Engine specifications
| Oil capacity | 14.2 L |
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| Coolant capacity | 14.2 L |
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| Displacement | 6.7 L |
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| Cylinders | 6 |
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| Aspiration | Turbocharged and Charge-Air Cooled |
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| Rated speed | 1470 rpm |
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| Gross power | 163 kW |
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Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Cummins Filtration AH1196 (standard) and AF26124/AF26125 (heavy duty) | | AF26124 | | Amazon $145.55 eBay $60.00 KuduParts $107.00 |
| Fuel filter | Cummins Filtration FF5612 (primary) and FS1212 (secondary) | | — | | |
| Oil filter | Full-flow with by-pass valve | | — | | |
| Battery | 12V-DC, 1500 watts | | 12V-DC | | Amazon Amazon eBay eBay $69.95 FridayParts $11.85 |
| Belt | Belt guard | | — | | |
| Coolant | Tube and shell type, 60 PSI with NPTF connections | 14.2 L | — | | |
| Coolant filter | Tube and shell type, 60 PSI with NPTF connections | | — | | |
| Oil | Oil pressure range at rated: 40-70 PSI (276-483 kPa) | | — | | |
| Spark plug | Engine only - cold cranking amperes: 1400 CCA*; Engine only - reserve capacity: 430 minutes* | | — | | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Service intervals
6| Item | Action | Hours | Months | Notes |
|---|
| Lubricating oil | Test | 250 hr | 6 mo | First service — For high horsepower engines with Eliminator™ oil filter option: take oil samples every 250 hours and analyze per Cummins Engine Oil Recommendations Bulletin 3810340; repeat for at least three oil change intervals. |
| filters | Change | 1000 hr | | with CENTINEL, depending on load factors |
| ELIMINATOR self cleaning filter core | Other | 1500 hr | | Requires servicing only every 1,500 hours. Saves up to 90% of lube system maintenance costs and increases productivity. |
| Overhead valve set | Adjust | 5000 hr | | QSM, QSX and QSK19 |
| fuel filter | Change | 1500 hr | | Fleetguard NanoNet media |
| engine oil | Change | 4500 hr | | with CENTINEL, railway applications |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Service specifications
4| Type | Item | Value | Unit | Condition |
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| Other | Pressure sensing line nominal size inside diameter | 1/2 | in. (12.7 mm) | connected between the transducer (located under the FPDP) and the pump discharge flange and the discharge check valve |
| Pressure | Cooling loop cooling water pressure limit | 270 | psi | installations where the discharge pressure is greater than 270 psi (pressure reducing valve required upstream of the cooling loop) |
| Pressure | Discharge set point pressure / maximum control pressure | 100/110, 170/175, or 240/250 | psi | set by the factory and not adjustable; specify at time of order |
| Pressure | VSPLC set point range | 100 to 400 | psi | |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Recommended fluids
| Fluid | Grade | Standard | Ambient | Capacity | Notes |
|---|
| Engine oil | | Cummins Engine Oil Recommendations Bulletin 3810340 | | | Used to analyze oil samples for high horsepower engines with Eliminator™ oil filter option. |
| Fuel | B100 biodiesel | ASTM D6751 | | | Must conform prior to blending; revised to include a cold soak test; stability requirement still in effect. |
| Fuel | B20 biodiesel blend | ASTM D7467 | | | Applies to biodiesel blends B6–B20; includes oxidation stability requirement; replaces Cummins' previous EMA B20 specification requirement. Must be purchased from a BQ9000 Certified Marketer; B100 must be sourced from a BQ9000 Accredited Producer. |
| Fuel | B5 biodiesel | | | | All Cummins automotive and industrial engines are compatible with B5 biodiesel. |
| Fuel | biodiesel (Europe) | EN 14214 | | | Published by CEN, European Committee for Standardization. Equivalent biodiesel specifications required internationally. |
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Procedures
2Oil sampling for high horsepower engines with Eliminator™ oil filter option maintenance
- Take oil samples every 250 hours of operation.
- Analyze samples according to Cummins Engine Oil Recommendations Bulletin 3810340.
- Repeat for at least three oil change intervals to ensure consistent oil behavior.
Switching from petrodiesel to B20 on used engines maintenance
⚠ B20 has a solvent nature and may clean the vehicle fuel tank and lines.
- Install new fuel filters when switching to B20.
- Replace fuel filters at half the standard interval for the next two fuel filter changes.
- After the initial period, revert to intervals specified in the O & M manual.
- For EPA 2007 on-highway midrange engines, sample oil for the first 6 months to monitor fuel dilution.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Parts cataloged across the Cummins/Onan QSB6.7 family
1| Part # | Description | Category |
|---|
| 9851268101e | LinkOne parts catalogue, CD | other_service |
Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.
Aftermarket parts that fit this engine
2Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.
Common questions
What is the oil capacity of the Cummins/Onan QSB6.7?
The Cummins/Onan QSB6.7 engine has an oil capacity of 14.2 liters.
What is the displacement of the Cummins/Onan QSB6.7?
The Cummins/Onan QSB6.7 has a displacement of 6.7 liters with 6 cylinders.
Which generators use the Cummins/Onan QSB6.7 engine?
The Cummins/Onan QSB6.7 powers 6 generator set(s), including Cummins/Onan CFP7E-F10, Cummins/Onan CFP7E-F50, Cummins/Onan CFP7EVS-F10, Cummins/Onan CFP7EVS-F50, Cummins/Onan QSB 6.7.