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davidbt's avatar
davidbt
Explorer
Mar 18, 2014

LLY and LBZ

Been reading a lot of posts, still trying to figure out the difference's between the two engines. I have an 04 2500 D/M LT with 99,600 miles. Bought the truck when it had only 73,000 miles on it.

21 Replies

  • This is the info I got when I bought our LBZ.

    * Cylinder block casting and machining changes strengthen the bottom of the cylinder bores to support increased horsepower and torque
    * Upgraded main bearing material increases durability
    * Revised piston design helps lower compression ratio to 16.8:1 from 17.5:1
    * Piston pin bore diameter increased for increased strength
    * Connecting rod “ I ” section is thicker for increased strength
    * Cylinder heads revised to accommodate lower compression and reduced 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

    * Fuel injectors spray directly onto glow plugs, providing faster, better-quality starts and more complete cold-start combustion for reduced emissions
    * 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 bring more exhaust 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 DURAMAX 6600 also has a new intake air heater to reduce smoke and emissions during cold or light-load driving. The system features a 1000-watt grid heater located in the air intake duct, which is triggered automatically by the engine controller. It heats up the incoming air to speed warm-up of the engine.

    In addition 50 more horsepower and 45 more lb-ft of torque in the Silverado and Sierra