What's different about the LMM compared to the LBZ, LLY and LB7?
Here is the REAL difference unlike above:blahblah1::blahblah1:
2008 DURAMAX DIESEL 6.6L V8 Turbo (LMM)
DURAMAX DIESEL 6.6L V8 Turbo (LMM) Truck Engine
2008 Model Year Summary
Carryover from 2007i model year
• New Engine For All Applications For The 2007 Interim Model Year
• New Fuel Injectors Improve Combustion Characteristics
• Durability Enhancement For Variable-Geometry Turbocharger
• Larger Exhaust Gas Recirculation Cooler
• Closed Crankcase Ventilation System
• Diesel Particulate Filter System
• Intake Throttle For Precise Combustion Temperature Control
• Electrically Variable Engine Cooling Fan
• Increased Engine Control Processing
• Lower Output Fleet Version Dropped
FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES
NEW ENGINE FOR ALL APPLICATIONS FOR THE 2007 INTERIM MODEL YEAR
The all-new 2007 Chevrolet Silverado and GMC Sierra 2500 HD and 3500, are the first pickup truck applications for the new Duramax Diesel 6.6L V8 Turbo (LMM), which will be introduced in January, 2007. In addition, the Chevrolet Express and GMC Savana full-size vans and Chevrolet Top Kick and GMC Kodiak medium-duty trucks will also be equipped with the newly engineered Duramax Diesel 6.6L V8 Turbo (LMM) beginning in January, 2007.
NEW FUEL INJECTORS IMPROVE COMBUSTION CHARACTERISTICS
Sophisticated solenoid injectors are used to precisely control combustion and to take advantage of the cleaner Ultra Low Sulfur fuel federally mandated to be available for all on-road diesel vehicles beginning in the 2007 model year. The injectors have six specially shaped holes, developed by Powertrain engineers to better atomize fuel for complete combustion of the fuel. The injectors are programmed to inject fuel into the combustion chamber at multiple intervals during one compression stroke. By doing this, the combustion event can be tailored to lower emissions and reduce noise at its source.
DURABILITY ENHANCEMENT FOR VARIABLE-GEOMETRY TURBOCHARGER
The unique variable-geometry vane-type turbocharger is housed inside the “V” of the Duramax Diesel 6.6L V8, where it is cooled by the engine’s cooling system. For 2007, the compressor is changed to a “boreless” type, which will increase durability at high rpm.
LARGER EXHAUST GAS RECIRCULATION COOLER
To help control combustion temperatures, exhaust gas is introduced into the intake system. The exhaust gas is also cooled inside an element, which was made larger for the 2007 model year to contribute to achieving lower emissions.
CLOSED CRANKCASE VENTILATION SYSTEM
The crankcase ventilation system is a sealed chamber between both cylinder banks of the Duramax Diesel 6.6L V8 Turbo to ensure that emissions from the crankcase are kept to a minimum.
DIESEL PARTICULATE FILTER SYSTEM
To accomplish a dramatic reduction in emissions of particulate matter (PM), a complex ceramic-type exhaust gas filter is installed behind the oxidizing catalyst already in the exhaust system. The filter replaces the muffler in location, and consists of hundreds of small, porous tubes blocked at one end, which force the exhaust gas through the walls of the tubes, which trap PM. The trapped particles are then burned off by the heat of the exhaust, which reaches 550 degrees Celsius. Sensors detect the differential pressure between exhaust gas entering and exiting the filter, and signal the engine control module (ECM) to adjust combustion to maintain the exhaust gas temperature. The use of Ultra Low Sulfur fuel is necessary, and it will be the only diesel fuel available for on-road vehicles at the beginning of the 2007 Model Year.
INTAKE THROTTLE FOR PRECISE COMBUSTION TEMPERATURE CONTROL
During low load conditions such as idling for extended periods and unladen low-speed driving, the temperature of the exhaust falls. To increase the amount of load on the engine during those periods, a throttle is added to the intake system, upstream of the turbocharger. This throttle is operated by the ECM as an additional control for combustion temperatures.
ELECTRICALLY CONTROLLED ENGINE COOLING FAN
On the Chevrolet Kodiak and GMC TopKick Medium Duty truck applications only, the engine cooling fan is now controlled by the ECM. This allows the engine cooling system to be assisted by the fan only when necessary, which results in more precise control over the engine temperature and also aids efficiency and improves fuel economy slightly.
INCREASED ENGINE CONTROL PROCESSING
The powerful E35 ECM which added more processing capacity for the 2006 Model Year is reprogrammed to include substantially more functions. Adding to the existing functions such as the variable-geometry turbocharger, the E35 ECM now controls the new injectors, the data from the diesel particulate filter pressure sensors, the new intake throttle operation, and the electrically variable engine cooling fan. ( Kodiak and TopKick )
LOWER OUTPUT FLEET VERSION DROPPED
The lower-output option for fleet versions of the engine that was introduced for the 2003 Model Year has been dropped.