Cummins Westport B6.7N
The Cummins Westport B6.7N is a 6.7-litre, six-cylinder inline natural gas engine for shuttle and school bus, as well as medium-duty truck applications. The engine is compatible with compressed natural gas (CNG), liquified natural gas (LNG), and renewable natural gas (RNG). Cummins announced the B6.7N in 2017, and it replaced the Cummins Westport ISB6.7 G in 2018.
The B6.7N uses a three-way catalyst which works by introducing a catalyst to convert the nitrogen oxides to nitrogen gas and oxygen gas, carbon monoxide to carbon dioxide, and hydrocarbons to carbon dioxide and water. The engine also features cooled exhuast gas recirculation (EGR) and spark-ignited stoichiometric combustion. Crankcase emissions are captured and rerouted back to the engine. A new engine control module offers faster processing and is telematics capable. The 2018 B6.7N is certified to CARB optional low NOx emissions standards of 0.1 g/bhp-hr and meets the 2017 EPA greenhouse gas emissions requirements.
- Cummins Westport B6.7N brochure. 2018