Duramax V8 engine
The Duramax V8 engine is a family of 6.6-liter diesel V8 engines produced by DMAX, a wholly owned subsidiary of General Motors in Moraine, Ohio. The Duramax block are supplied by Fritz Winter, a German foundry. The 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 was first introduced in 2001 and continued until early 2004. It featured a 32-valve design with high-pressure common-rail direct injection and aluminum cylinder heads.The following trucks use the LB7:
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
LLY
The LLY 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-only Hummer H1 Alpha
- Chevrolet Silverado/GMC Sierra 2500HD/3500
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. This also marked the first appearance of the Duramax in the Express/Savana vans. The LBZ is one of the more sought-after Duramax engines because of its strength, reliability, and being pre-emissions.
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 added strength
- Connecting rod "I" section is thicker for added 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
- Chevrolet Silverado 2500HD/3500
- Chevrolet Kodiak
- GMC Sierra 2500HD/3500
- GMC TopKick
- Chevrolet Silverado/GMC Sierra 2500HD/3500 Classic
- Chevrolet Silverado 2500HD/3500
- Chevrolet Kodiak
- GMC Sierra 2500HD/3500
- Chevrolet Express full-size
- GMC Savana full-size
Specifications
- Block / Head: Cast gray iron / Cast aluminum
- Compression: 16.8:1
- Injection: Bosch high-pressure common-rail
- Power / Torque: 360 bhp @3200 rpm / 650 lb-ft @1600 rpm
| Code | Years | Power output | Torque | Redline |
| LB7, GMC Sierra 2500HD / 3500 Classic ) | 2001–2004 | @ 3200 rpm | @ 1600 rpm | 3450 rpm |
| LLY, GMC TopKick Medium Duty | 2004–2005 | @ 3000 rpm | @ 1600 rpm | 3200 rpm |
| LBZ, GMC TopKick Medium Duty ) | 2006–2007 | @ 3000 rpm | @ 1600 rpm | 3200 rpm |
| LLY | 2006–2007 | @ 3200 rpm | @ 1600 rpm | 3450 rpm |
LMM
The LMM 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
| Code | Years | Power output | Torque | Redline |
| LML | 2011–2016 | @ 3000 rpm | @ 1600 rpm | 3450 rpm |
| LMM | 2007–2010 | @ 3200 rpm | @ 1600 rpm | 3450 rpm |
| LMM | 2007–2010 | @ 3000 rpm | @ 1600 rpm | 3250 rpm |
| LMM | 2007–2010 | @ 3000 rpm | @ 1600 rpm | 3250 rpm |
| LMM | 2007–2010 | @ 3200 rpm | @ 1600 rpm | 3450 rpm |
| LGH | 2010–2016 | @ 3100 rpm | @ 1600 rpm | 3450 rpm |
Emission controls:
- Additional combustion control, including an even more efficient variable-geometry turbocharging system, cooled exhaust gas recirculation, and closed crankcase ventilation to reduce nitrogen oxides
- Additional exhaust control, including oxidizing catalyst and new diesel [particulate filter] to reduce soot and particulate matter
- Increased-capacity cooling system
- New engine control software
- Use of low-ash engine oil
- 2007–2010 Chevrolet Silverado HD
- 2007–2010 GMC Sierra HD
- 2007–2010 Chevrolet Kodiak
- 2007–2010 GMC TopKick
- 2007–2010 Chevrolet Express/GMC Savana
LGH
The 6.6L Duramax diesel engine is used on 2010 interim and 2011 Chevrolet Express and GMC Savana vans and 2011 Chevrolet Silverado/GMC Sierra HD trucks with RPO ZW9. The LGH engine is rated at at 3,100 rpm and at 1,600 rpm. Similar to the LML, this engine also uses a DPF and DEF system to meet emissions standards.LML
The 6.6L RPO LML 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 comply with the new federal emissions standards for diesel engines, provide better engine rigidity, and further noise reduction. The engine gained new 29,000 PSI piezo injectors as well as a completely reworked fuel system which was now powered by the Bosch CP4 pump, that also now supports up to 20% biodiesel mixtures and a urea injection with a 5.3 gallon DEF tank. 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 3,000 rpm and of torque at 1,600 rpm.