The L9N is the natural choice in alternative-fuel engine technology. With industry leading performance, it combines all the advantages of clean burning, low cost natural gas with “no compromises” in power and torque. The L9N  is an upgraded evolution of the proven ISL G, moving to the latest Euro 6 Phase D emissions with minimal changes retaining the impressive low-end toque, transient response and quiet operation for bus and truck applications.

The L9N engine block is shared with the Cummins L9 diesel – a full skirted block for increased rigidity and strength. The design provides superior piston ring and bearing life, improved coolant flow and targeted piston cooling, for greater reliability and superior durability. The engine’s life to rebuild and rebuildability are similar to those of diesel engines. The 8.9 litre L9N uses advanced stoichiometric combustion with cooled Exhaust Gas Recirculation (EGR) to meet ultra-low emissions requirements. The cooled-EGR system takes a measured quantity of exhaust gas and passes it through a cooler to reduce temperatures before mixing it with fuel and the incoming air charge to the cylinder. This lowers combustion temperatures and knock tendency, reducing engine out emissions and noise. With a pedigree of millions of engines to date, Cummins cooled EGR technology is proven in a wide range of installations.

Stoichiometric combustion is the ideal combustion process where all fuel and oxygen is completely consumed. This means that no unburned fuel or oxygen exits through the exhaust. Combined with cooled EGR it improves power density and fuel economy to create a high performance natural gas engine. It also enables the use of simpler, lower cost exhaust aftertreatment systems. Compared with previous Cummins lean-burn natural gas engines, L9N torque at idle is improved over 30 percent, and fuel economy is improved by up to 5 percent.

Features & Benefits

• Factory-Built, Dedicated Natural Gas Engine – manufactured by Cummins on the same assembly line as Cummins diesels, the L9N shares many components and parts with Cummins L Series diesels, inheriting their renowned simplicity.
• Heavy-Duty Design – rugged features include replaceable wet liners, roller followers, by-pass oil filtration and targeted piston cooling for longer service in the toughest work environments.
• Fuel Capability – the L9N is capable of operating on compressed or liquefied natural gas (CNG, LNG). The L9N can also operate on up to 100 percent biomethane, renewable natural gas made from biogas or landfill gas that has been upgraded to pipeline and vehicle fuel quality.
• Air/Fuel Regulation – Cummins closed-loop electronic control system with sensors for engine parameters, including intake manifold pressure and temperature, fuel inlet pressure, knock detection, air/fuel ratio and fuel mass flow.
• High Power and Torque – available up to 320ps with 1356 Nm of torque for alternative fuel truck and bus applications.
• Closed crankcase ventilation (CCV) – new remote mounted system required to re-cycle blow-by gases now counted in the engine emissions.
• Cummins Wastegated Turbocharger – developed by Cummins Turbo Technologies with electronic control for precise air handling. Has a water-cooled bearing housing for durability.
• Air Intake System – charge air cooling reduces emissions by lowering intake manifold air temperatures.
• Maintenance-Free Aftertreatment – uses a Three-Way Catalyst (3WC) aftertreatment. 3WCs are effective, simple, passive devices, packaged as part of the muffler, that provide consistent emissions control performance and are maintenance-free. The L9N does not require active aftertreatment such as a Diesel Particulate Filter (DPF) or Selective Catalytic Reduction (SCR).
• High-Energy Ignition System – spark ignited system providing better performance and longer service intervals with improved spark-plug and coil durability.
• High-Efficiency Lube Cooler – lowers oil temperatures for longer engine life.
• Accessory Belt Drive System – self-tensioning serpentine polyvee belt accessory drive system for water pump, engine-mounted fan hub and most alternators. Gear-driven air compressor with provision for gear-driven hydraulic pump.
• Crankshaft – eight counterweight, fully balanced, hightensile- strength steel forging with induction hardened fillets and journals, for outstanding durability.
• Control System – full drive-by-wire. Electronic Control Module (ECM) provides full monitoring and control of the engine sensors, fuel system and ignition system. Full interface capability to Cummins INSITE and diagnostic service tools.
• Oil Filter – the combination full-flow and bypass oil filter improves filtration while minimizing oil filter replacement and disposal costs.
• Global Support – backed by the widest network in the industry, with over 5,000 service outlets worldwide.

Contact your local customer assistance centre for technical support, details on www.cummins.com/customer-assistance