Duramax V8 engine

The Duramax V8 engine is a family of 6.6 liter Diesel V8 engines produced by DMAX, a joint venture between General Motors and Isuzu in Moraine, Ohio. The Duramax block and heads are supplied from reliable vendors of General Motors. This engine was initially installed in 2001 Chevrolet and GMC trucks, and has since become an option in pickups, vans, and medium-duty trucks. In 2006, production at Moraine was reportedly limited to approximately 200,000 engines per year. On May 9, 2007, DMAX announced the production of the 1,000,000th Duramax V8 at its Moraine facility, followed by the 2,000,000th on March 24, 2017.

Engine RPO Codes

LB7

RPO LB7 (engine code "1") was first introduced in 2001 and continued until early-2004. It is a 32-valve design with high-pressure common-rail direct injection and an experimental composite design cylinder head.

The following trucks use the LB7:
* Chevrolet Kodiak/GMC Topkick
* Chevrolet Silverado/ GMC Sierra HD

Specifications

* Block / Head: Cast Iron / Aluminum
* Compression: 17.5:1
* Injection: Direct; Bosch high pressure common-rail
* Power / Torque: at 3,100 rpm at 1,800 rpm
The LLY was introduced in 2004 and replaced the LB7 completely mid-year

LLY

The LLY (internally called the ''8GF1'') (engine code "2") is a turbocharged engine which debuted in mid-2004 and continued until the end of 2005. It is a 32-valve design with high-pressure common-rail direct injection and aluminum cylinder heads. The LLY was GM's first attempt to implement emissions requirements on their diesel trucks. To meet this goal, they turned to a newly developed Garrett turbocharger with a variable geometry vane system and installed an EGR Valve. Learning from problems with injectors in the previous LB7, GM changed the valve covers to allow access to the injectors without having to remove the valve covers, saving significant labor costs if injector replacement became necessary.

The following trucks used the LLY engine:
* 2006 Hummer H1 Alpha
* Chevrolet Silverado/ GMC Sierra HD

Specifications

* Block / Head: Cast gray iron / Cast aluminum
* Compression: 17.5:1
* Injection: Bosch High Pressure Common-rail
* Power / Torque: at 3000 rpm / at 1600 rpm
* Head casting is 8gf1
* Block casting is #22351021213

LLY/LBZ

There are two VIN codes for the LBZ. The first is VIN 2 produced in late 2005 and early 2006. The VIN 2 engine is mechanically and physically the same as the VIN D engine but utilizes LLY engine tuning due to the LBZ tuning taking longer to be EPA certified and placed into production.

The second is VIN D. This was introduced in 2006 and continued into 2007 sold only in the "classic" body style. It has an improved engine computer tune that produces increased power and torque over the 2005 LLY version of the engine. First appearance of the Duramax in the Express/Savanna vans. The LBZ is one of the more sought after Duramax engines due to its strength, reliability, and being pre-emissions ( DPF appeared on the next generation LMM in 2007).

Changes include:
* Cylinder block casting and machining changes strengthen the bottom of the cylinder bores to support increased power and torque
* Upgraded main bearing material increases durability
* Revised piston design lowers 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 to more than
* 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

LBZ applications:

* Chevrolet Silverado HD
* Chevrolet Kodiak
* GMC Sierra HD
* GMC TopKick

LLY applications:
* Chevrolet Silverado HD
* Chevrolet Kodiak
* GMC Sierra HD
* Chevrolet Express full-size (reduced power output mated to a 4L85E transmission)
* GMC Savana full-size (reduced power output mated to a 4L85E transmission)

Specifications

2007 LLY LBZ spec sheet
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* Block / Head: Cast gray iron / Cast aluminum
* Compression: 16.8:1
* Injection: Bosch High Pressure Common-rail
* Power / Torque:

LMM

The LMM (engine code "6") debuted part way through 2007 and ended production with the start of the 2011 calendar year and is mated to the 6-speed Allison transmission. The LMM was the only Duramax offered for model years 2007–2010. A version was used in the Trident Iceni.

Specifications

* Block / Head: Cast gray iron / Cast aluminum
* Compression: 16.8:1
* Injection: Bosch High Pressure Common Rail with CP3.3 Injection Pump
* Power / Torque: at 3200 rpm / at 1600 rpm

Emission controls:
* Additional combustion control, including an even more efficient variable-geometry turbocharging system, cooled (enhanced) exhaust gas recirculation (EGR) and closed crankcase ventilation to reduce nitrogen oxides (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 (CJ-4)

Applications:
* 2007– Chevrolet Silverado HD
* 2007– GMC Sierra HD
* Chevrolet Kodiak
* GMC Topkick
* Chevrolet Express/GMC Savanna

LGH

The 6.6L Duramax diesel engine (VIN code "L") is used on 2010 interim and 2011 Chevrolet Express and GMC Savana vans and 2011 Chevrolet Silverado and GMC Sierra trucks with RPO ZW9 (chassis cabs or trucks with pickup box delete). The LGH engine is rated at at 3100 rpm and at 1600 rpm. Similar to the LML this engine also uses a DPF and DEF system to meet emission standards.

LML

The 6.6L RPO LML (VIN code "8") is the 2011–2016 version of the Isuzu/GM Duramax V8 diesel engine. It is a further advanced version of the LMM engine with the majority of the changes addressing a required drastic reduction in engine emissions. Some mechanical aspects of the engine, such as piston oil flow design for improved temperature control and oil pump design, were also improved to enhance durability even further.

The LML engine was significantly updated for 2011 to provide improved exhaust emissions that comply with the new federal emission standards for diesel engines, provide better engine rigidity and further noise reduction. New 29,000 PSI piezo injectors, a complete fuel system-hardening to tolerate up to 20% biodiesel mixtures and urea injection (to reduce nitrogen oxides) with a 5.3 gallon urea tank are updating the fuel and emissions systems. This engine has a fuel injector in the exhaust tract, to allow raw fuel injection during the particulate filter recycling routine. The RPO LML engine is rated at at 3000 rpm and of torque at 1600 rpm.

L5P

The L5P duramax is the latest version of the Duramax V8 diesel engine.(engine code Y) Introduced in the 2017 model year it is the most powerful diesel pickup truck engine GM has produced with at 2,800 rpm and at 1,600 rpm. Design spec performance can exceed at 3050 rpm and at 1975 rpm.

L5D

The L5D Duramax is a downrated version of the L5P for the Chevy Silverado MD and International CV trucks (Class 4,5,6). The L5D was downrated to increase reliability and reduce downtime. The L5D was introduced in 2018 for the 2019 model year Chevy Silverado MD and International CV trucks. Specifications for the L5D are at 2600 RPM and at 1600 RPM.

See also

* List of GM engines
* Allison 1000 transmission

References

External links

LML DURAMAX

Duramax home page

DMAX, Ltd. home page

Duramax Diesel Specs

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