Duramax LLY
The LLY (internally called the 8GF1) is a 6.6 L (6599 cc) turbocharged engine which debuted in 2004 in GM trucks. It is a 32-valve design with high-pressure common-rail direct injection and aluminum cylinder heads. Output is 310 hp (231 kW) at 3100 rpm and 605 lb·ft (820 N·m) at just 1800 rpm. The engine was released with a new Garrett turbocharger with a variable geometry vane system. The valve covers were scalloped to allow access to the injectors without having to remove the valve covers, saving significant labor costs if injector replacement became necessary, and preventing leaked fuel from entering the crankcase, causing oil dilution.
The following trucks used the LLY engine:
The following trucks used the LLY engine:
- 2006 Hummer H1 Alpha
- Engine Code: LLY
- Displacement: 6.6L / 403 in³
- Bore x Stroke: 4.06 in (103 mm) x 3.90 in (99 mm)
- Block / Head: Cast gray iron / Cast aluminum
- Aspiration: Turbocharged & Intercooled
- Valvetrain: OHV 4-V
- Compression: 17.5:1
- Injection: Direct; Bosch High Pressure Common-rail
- Power / Torque: 310 hp (231 kW) @ 3,000 rpm / 605 lb·ft (820 N·m) @ 1,800 rpm




