General Motors announced this week upgrades to its Duramax 6.6L V-8 turbo-diesel engine to meet government-mandated emissions regulations for diesel engines manufactured beginning in January 2007. To meet the new emissions regulation, the Duramax 6.6L V-8 engine features:
Additional combustion control, including a more efficient variable-geometry turbocharging system, cooled (enhanced) Exhaust Gas Recirculation (EGR) and closed crankcase ventilation to reduce NOx
Additional exhaust control, including oxidizing catalyst and new Diesel Particulate Filter (DPF) to reduce soot and particulate matter
Increased-capacity cooling system
New engine control software The new Duramax 6.6L V-8 (LMM) engine is offered with increased power and torque for Chevy Kodiak and GMC Topkick medium duty applications. Versions are available with 300 horsepower and 520 lb.-ft. of torque, as well as a new 330-horsepower option with 620 lb.-ft. of torque. Additional details of the Duramax 6.6L V-8 engine's '06 enhancements include:
Cylinder block casting and machining changes to provide stronger structures with increased reliability and durability
Revised piston design lowers compression ratio from 17.5:1 to 16.8:1
Cylinder heads revised to accommodate higher peak cylinder firing pressure
Maximum injection pressure increased from 23,000 psi to more than 26,000 psi
Fuel delivered via higher-pressure pump, fuel rails, distribution lines and all-new, seven-hole fuel injectors
Improved glow plugs heat up faster through an independent controller
Revised variable-geometry turbocharger is aerodynamically more efficient to help deliver smooth and immediate response and lower emissions
Air induction system re-tuned to enhance quietness
EGR has larger cooler to provide for cooler exhaust gases going into the system
First application of new, 32-bit E35 controller, which adjusts and compensates for the fuel flow to bolster efficiency and reduce emissions
