| Duramax Diesel engine | |
| Manufacturer: | DMAX Ltd. |
| Production: | 2001–present |
| Configuration: | 90° V8 |
| Predecessor: | 6.2 and 6.5 L Detroit Diesel |
| Valvetrain: | OHV 4 valves x cyl. |
| Fueltype: | Diesel |
| Fuelsystem: | High-pressure common-rail direct injection |
| Coolingsystem: | Water-cooled |
| Block: | Cast gray iron |
| Head: | Aluminum |
| Turbocharger: | Garrett variable-geometry vane with intercooler |
| Timing: | Gears |
| Compression: | 16.8:1, 17.5:1 |
| Management: | Bosch |
| Emissions Control: | Oxidizing catalyst, DPF, EGR |
| Emissions Level: | EPA |
| Displacement: | 6599cc |
| Bore: | 103mm[1] |
| Stroke: | 99mm |
| Power: | NaNhp |
| Torque: | NaN0NaN0 |
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 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.[2] 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.[3]
RPO LB7 (engine code "1") 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.[4]
The following trucks use the LB7:
The LLY was introduced in 2004 and completely replaced the LB7 mid-year.
The LLY (internally called the 8GF1) (engine code "2") is a 6599cc turbocharged engine which debuted in mid-2004 and continued until the end of 2005 (except the Hummer H1 in 2006). 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:
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 (DPF appeared on the next generation LMM in 2007).
Changes include:
LBZ applications:
LLY applications:
| Code | Years | Power output | Torque | Redline |
|---|---|---|---|---|
| LB7 (Chevrolet Silverado 2500HD / 3500 Classic (auto trans), GMC Sierra 2500HD / 3500 Classic (auto trans)) | 2001–2004 | 3000NaN0 @ 3200 rpm | 5200NaN0 @ 1600 rpm | 3450 rpm |
| LLY (Chevrolet Kodiak Medium Duty (LRX option), GMC TopKick Medium Duty (LRX option), Hummer H1 Alpha) | 2004–2005 | 3100NaN0 @ 3000 rpm | 6050NaN0 @ 1600 rpm | 3200 rpm |
| LBZ(Chevrolet Kodiak Medium Duty (LPD option), GMC TopKick Medium Duty (LPD)) | 2006–2007 | 6050NaN0 @ 1600 rpm | ||
| LLY (Chevrolet Express, GMC Savana) | 2500NaN0 @ 3200 rpm | 4600NaN0 @ 1600 rpm | 3450 rpm |
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.[6] A version was used in the Trident Iceni.[7]
| Code | Years | Power output | Torque | Redline |
|---|---|---|---|---|
| LML (Chevrolet Silverado/GMC Sierra HD) | 2011–2016 | 3970NaN0 @ 3000 rpm | 7650NaN0 @ 1600 rpm | 3450 rpm |
| LMM (Chevrolet Silverado/GMC Sierra HD) | 2007–2010 | 3650NaN0 @ 3200 rpm | 6600NaN0 @ 1600 rpm | |
| LMM (Chevrolet Kodiak/GMC TopKick (LYE option)) | 3300NaN0 @ 3000 rpm | 6200NaN0 @ 1600 rpm | 3250 rpm | |
| LMM (Chevrolet Kodiak/GMC TopKick (LRX option)) | 3000NaN0 @ 3000 rpm | 5200NaN0 @ 1600 rpm | ||
| LMM (Chevrolet Express/GMC Savana) | 2500NaN0 @ 3200 rpm | 4600NaN0 @ 1600 rpm | 3450 rpm | |
| LGH (Chevrolet Express/GMC Savana) | 2010–2016 | 2600NaN0 @ 3100 rpm | 5250NaN0 @ 1600 rpm |
Emission controls:
Applications:
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/GMC Sierra HD trucks with RPO ZW9 (chassis cabs or trucks with pickup box delete). The LGH engine is rated at 3350NaN0 at 3,100 rpm and 6850NaN0 at 1,600 rpm. Similar to the LML, this engine also uses a DPF and DEF system to meet emissions standards.
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 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 (to reduce nitrogen oxides) 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 397hp at 3,000 rpm and 7650NaN0 of torque at 1,600 rpm.[11]
The L5P Duramax is the latest version of the Duramax V8 diesel engine.(engine code Y). Introduced in the 2017 model year, it was the most powerful diesel engine GM had produced, with 445hp at 2,800 rpm and 9100NaN0 at 1,600 rpm. Design specification performance can exceed 550bhp at 3,050 rpm and 10500NaN0 at 1,975 rpm.
The L5P Duramax received an increase in horsepower and torque for the 2024 model year; 470hp at 2,800 rpm and 9750NaN0 at 1,600 rpm. Design specification performance can exceed 550bhp at 3050 rpm and 10500NaN0 at 1975 rpm.[12]
The L5D Duramax is a downrated version of the L5P for the Chevrolet Silverado MD and International CV trucks (Class 4, 5, and 6). The L5D was downrated to increase reliability and reduce downtime. The L5D was introduced in 2018 for the 2019 Chevrolet Silverado MD and International CV trucks. Specifications for the L5D are 350hp at 2,600 rpm and 7000NaN0 at 1,600 rpm.