LB7 Duramax Diesel

Related Topics:

6.6L Duramax LBZ

6.6L Duramax LLY

6.6L Duramax LMM

6.6L Duramax LML

Allison 1000 Transmission













Return to Duramax Diesel Specs.


6.6L Duramax LB7







The LB7 Duramax was first introduced in 2001 and produced until 2004. The 32 valve, V8 design utilizes a high pressure common rail direct injection system. Due to the lack of emission equipment, the LB7 is considered one of the most sought after Duramax's built, praised for great fuel mileage and having the simplest design.



6.6L Duramax LB7 Specs


6.6L Duramax LB7, 90 degree V8, diesel.

Years Produced:

2001 - 2004

VIN Code:

1 (8th digit of VIN)


403 cubic inches, 6.6 liters.

Head/Block Material:

Aluminum cylinder heads, cast iron engine block.

Compression Ratio:

17.5 : 1

Firing Order:



4.06 inches.


3.90 inches.


Turbocharged & intercooled (air-to-air). Max boost pressure approximately 20 psi.


Direct injection, Bosch 23,000 psi high pressure common rail with CP3 injection pump.


OHV (overhead valve), 4 valves per cylinder.

Oil Capacity:

10 quarts w/ filter.

Engine Weight:

Approx. 835 lbs.

Max Engine Speed:

3,250 rpm.

Peak Horsepower:

• 235 hp @ 2,700 rpm (2001 model year).
• 300 hp @ 3,100 rpm (2004 model year).

Peak Torque:

• 500 lb-ft @ 1,600 rpm (2001 MY).
• 520 lb-ft @ 1,800 rpm (2004 MY).


Additional Duramax LB7 Info:

• LB7 applications include the Chevrolet Silverado HD, GMC Sierra HD, Chevrolet Kodiak, GMC Topkick.
• LB7 injectors often failed and required frequent replacement. GM eventually recalled the poorly designed injectors, and the factory warranty was extended to cover the new injectors for up to 200,000 miles.
• The LB7 Duramax was featured in Ward's 10 Best Engines for 2001 & 2002.
• Possibly the most fuel efficient Duramax due to its lack of emissions equipment, which notoriously dampens fuel economy.
• Cast iron engine block with aluminum cylinder heads. At inception, many were weary of using aluminum heads on the high compression diesel, but the design has proven iteself over the years.
• 4 bolt mains, 2 vertical, 2 horizontal.
• At 34.88 inches long, the Duramax is over an inch shorter than the 6.5L GM diesel.
• Aluminum pistons with piston cooling jets for lower combustion & piston temperatures.
• Forged & fractured connecting rods.
• The LB7 was available mated to an Allison 5 speed automatic transmission or ZF 6 speed manual transmission.
• The LB7 Duramax was produced from 2001 to 2004.