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GM'S 2007 Duramax 6.6L V-8 Turbo-Diesel Delivers Class-Leading Torque While Meeting New Emissions Requirements

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Duramax 6.6L Diesel Engine

MILFORD, MI - August 25, 2006: GM Powertrain's powerful Duramax 6.6L V-8 turbo-diesel engine is revised to meet new, stringent 2007 federal emissions regulations and continues to deliver the outstanding power and torque ratings customers expect.

Upgrades to the engine and a new diesel particulate filter system help ensure the engine meets government-mandated emissions regulations for diesel engines manufactured beginning in January 2007, which require a 90-percent reduction in particulate matter and 50-percent reduction in NOx.

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GMC Topkick

"Maintaining power and torque leadership with the Duramax is important to us because it's the benchmark that built the engine's class-leading reputation with our customers," said Charlie Freese, executive director, GM Powertrain Diesel Engineering.

The new Duramax 6.6L V-8 (LMM) engine delivers superior performance

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Chevy Kodiak

ratings. It 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.

Final advertised ratings for the Chevrolet Silverado and GMC Sierra 2500 and 3500 HD pickups and GM's full-size vans will be released later this year.

Chevrolet Silverado & GMC Sierra

The Duramax delivers outstanding acceleration and towing performance. Upgrades implemented in 2006 enhanced the efficiency, smoothness and quietness of the Duramax engine, which was already known as one of the industry's quietest and strongest diesels.

The new emissions standard

The Duramax 6.6L V-8 has new equipment to help it meet the government-mandated 2007 emissions standard. It requires a 90-percent reduction in particulate matter compared with the current standard, which was implemented in 2004, and a 50-percent reduction in NOx.

The use of reformulated, ultra-low sulfur diesel fuel - which goes on sale nationwide this fall - is required to meet the new emissions standard. The new fuel's sulfur content is limited to 15 parts per million (ppm), versus the current standard of 500 ppm. Diesel engines manufactured prior to 2007 can continue to use the current diesel fuel.

To meet the new emissions regulation, the Duramax 6.6L V-8 engine features:

Additional combustion control, including an even 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 Use of low-ash engine oil How the DPF works

The 6.6L engine's DPF is based on GM-patented technology and proven supplier components. It traps diesel particulate matter in a honeycomb-like ceramic "brick" after it travels through an oxidizing catalyst. Remaining exhaust gases are routed out through the exhaust system. To ensure optimal performance, the system must undergo periodic "regeneration" to release accumulated soot from the filter. The regeneration process uses heat to burn off the soot and, in most cases, is performed automatically.

An onboard computer controls fuel injection and oxygen content to adjust the exhaust energy to the appropriate level to clean the particulate trap. Periodic servicing of the filter is required to remove accumulated ash. The DPF and corresponding components will change the exhaust system length and/or outlet design, depending on the vehicle model. Also, an expanded underbody heat shield is added. Vocations such as sweepers, airport ground support, municipal and refuse trucks will likely be most affected by the changes.

Duramax 6.6L V-8 details

Revised for 2006, the Duramax diesel uses a variable-geometry turbocharger to optimize boost performance over a wide range of operating conditions. This provides the customer with seamless and immediate response, while simultaneously helping to reduce emissions. The turbo, which spins up to 120,000 rpm, is high-speed-balanced for minimal noise and vibration, while contributing to the engine's overall smoothness and refinement. Maximum boost is 20 psi. 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 Upgraded main bearing material increases 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

The engine also features a rigid cast iron cylinder block with induction-hardened cylinder bores; four-bolt, cross-drilled main bearing caps; forged steel, nitride-hardened crankshaft; aluminum pistons with jet-spray oil cooling; aluminum cylinder heads with four valves per cylinder; integrated oil cooler and a charge-cooled turbocharging system. Features, such as easy-access fuel filter and timing gears, reduce maintenance time and effort.


2007i Duramax Diesel 6.6L V-8 Turbo ( LMM )

Type: Duramax 6.6L V-8 turbo-diesel

Displacement: 6599cc

Compression ratio: 16.8:1

Valve configuration: overhead valves (4 valves per cylinder)

Assembly site: Moraine, Ohio

Valve lifters: mechanical roller

Firing order: 1 - 2 - 7 - 8 - 4 - 5 - 6 - 3

Bore x stroke: 103 x 99mm

Fuel system: direct-injection diesel with high pressure common rail

Applications: Horsepower: hp ( kW )

Chevrolet Silverado HD 360 hp ( 268kW ) @ 3200 rpm*

GMC Sierra HD 360 hp (268kW) @3200 rpm*

Chevrolet Kodiak Medium Duty ( LYE option ) 330 hp ( 246kW ) @ 3000 rpm

GMC TopKick Medium Duty ( LYE option ) 330 hp ( 246kW ) @ 3000 rpm

Chevrolet Kodiak Medium Duty ( LRX option ) 300 hp ( 224 kW ) @ 3000 rpm

GMC TopKick Medium Duty ( LRX option ) 300 hp ( 224 kW ) @ 3000 rpm

Chevrolet Express 250 hp ( 186 kW ) @ 3200 rpm*

GMC Savana 250 hp (186 kW) @ 3200 rpm*

Applications: Torque: lb-ft ( Nm )

Chevrolet Silverado HD 650 lb-ft ( 881 Nm ) @ 1600 rpm*

GMC Sierra HD 650 lb-ft (881 Nm) @ 1600 rpm*

Chevrolet Kodiak Medium Duty ( LYE option ) 620 lb-ft ( 841 Nm ) @ 1600 rpm

GMC TopKick Medium Duty ( LYE option ) 620 lb-ft (841 Nm) 2 1600 rpm

Chevrolet Kodiak Medium Duty ( LRX option ) 520 lb-ft ( 705 Nm ) @ 1600 rpm

GMC TopKick Medium Duty ( LRX option ) 520 lb-ft (705 Nm) @ 1600 rpm

Chevrolet Express 460 lb-ft. ( 624 Nm ) @ 1600 rpm*

GMC Savana 460 lb-ft (624 Nm) @ 1600 rpm*

Fuel shut off: 3250 rpm Kodiak and TopKick (medium duty) 3450 rpm Silverado and Sierra (heavy duty), Express and Savana

Emissions controls: cooled exhaust gas recirculation, catalytic converter, diesel particulate filter (DPF) & intake throttle


Block: cast iron

Cylinder head: cast aluminum

Intake manifold: cast aluminum

Exhaust manifold: cast nodular iron with steel pipe extension

Main bearing caps: cast nodular iron

Crankshaft: forged steel

Camshaft: steel

Connecting rods: forged steel, stress fractured

Additional features: charge air cooling recommended oil change interval: Per the computerized Oil Life System. Requires CJ-4 engine oil to Maximize Life recommended coolant change interval: 5 years or 150,000 miles

* Final advertised power ratings will be announced later this year.