B6.7N

Cummins Westport introduces the new B6.7N natural gas engine for the school bus, shuttle, and medium-duty truck markets. Rated up to 240 hp / 560 lb-ft torque, the B6.7N offers a reliable, low-emissions, and low cost option for your fleet. The B6.7N is certified to California Air Resources Board Optional Low NOx standard of 0.1 g/bhp-hr - 50% fewer NOx emissions than current EPA regulations.

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NOx emission 0.1 g / bhp-hr. (50% below EPA)
Maximum Horsepower 240 HP | 179 kW
Peak Torque 560 LB-FT | 759 Nm
Governed Speed 2,630 rpm
Type 4-cycle, spark-ignited, in-line
6 cylinder, turbocharged, CAC
Engine Displacement 409 CU IN | 6.7 LITERS
Number of Cylinders 6
Operating Cycles 4
Net Weight (dry) 1,150 lb | 522 KG
Fuel Type CNG / LNG / RNG
Aftertreatment Three-Way Catalyst
Base Warranty 2 Years, Unlimited Miles
Engine Model Advertised Horsepower
(kW) @ rpm
Peak Torque 
lb-ft (N•m) @ rpm
Governed
Speed
Truck    
B6.7N 200 200 (149) @ 2400  520 (705) @ 1600 2630 rpm
B6.7N 220 220 (164) @ 2400  520 (705) @ 1600  2630 rpm
B6.7N 240 240 (179) @ 2400  560 (759) @ 1600  2600 rpm
School Bus    
B6.7N 200 200 (149) @ 2400  520 (705) @ 1600 2630 rpm
B6.7N 220 220 (164) @ 2400  520 (705) @ 1600  2630 rpm
B6.7N 240 240 (179) @ 2400  560 (759) @ 1600  2600 rpm
Shuttle Bus    
B6.7N 200 200 (149) @ 2400  520 (705) @ 1600 2630 rpm
B6.7N 220 220 (164) @ 2400  520 (705) @ 1600  2630 rpm
B6.7N 240 240 (179) @ 2400  560 (759) @ 1600  2600 rpm

B6.7N < 33,000 lb (14,968 kg) GVW

Overall, maintenance for the B6.7N  is similar to that of diesel engines, but there are a few key differences:

  • Motor oil specifically formulated for natural gas engines is required. Do not use diesel engine oil in a natural gas engine. If diesel engine oil is used, valve torching, piston scuffing and reduction in spark-plug life will occur.  
  • For more information, see the links below or visit Cummins QuickServe Online.
Maintenance Item^ Hours Distance Months
Oil And Filter* 500 15,000 mi (24,000 km) 6
Spark Plugs 750 25,000 mi (40,000 km) 9
Spin-on Fuel Filter 1,000 30,000 mi (48,000 km) 12
Overhead Set Adjustment 1,500 45,000 mi (72,000 km) 18
Coolant System Drain 2,000 60,000 mi (96,000 km) 2 yrs
Closed Crankcase Ventilation Filter 2,000 60,000 mi (96,000 km) 2 yrs
Ignition Coil Extension 5,000 150,000 mi (240,000 km) 5 yrs
Air cleaner / element Follow manufacturer's published recommendations

Consult your Owners or Operation and Maintenance manual for the complete daily and routine maintenance schedule
^Based on a duty cycle of 30 mph / 48 kph average speed. Distance intervals may decrease based on average speed.
*Requires Natural Gas Engine Oil. 

  • Electronic Control Module: A new engine control module, CM2380, provides full monitoring and control of the engine sensors, and the fuel and ignition systems. It offers faster processing to support heavy duty On-Board Diagnostics requirements (500K baud rate). It is also telematics capable, and provides improved diagnostics and durability.
  • On-Board Diagnostics (OBD): The OBD system continuously monitors the engine and after-treatment system. It gives the vehicle owner or repair technician electronic access to the status of various vehicle subsystems for diagnostic purposes.
  • Closed Crankcase Ventilation (CCV) system: The CCV system reduces engine emissions by capturing crankcase emissions and rerouting these gases back to the engine. This results in more complete combustion and lower emissions.
  • Enhanced Three-Way Catalyst (TWC): TWCs are effective, simple, passive devices. They provide consistent emissions control performance, are maintenance-free and can be mounted vertically or horizontally on the vehicle. No active aftertreatment such as a diesel particulate filter or selective catalytic reduction is required.

  • High-Energy Ignition System: A new Ignition Control Module (ICM) provides better performance and improved spark plug and coil durability, plus self-diagnostics.