| GM High Value engine | |
| Manufacturer: | General Motors |
| Production: | 2004–2011 |
| Successor: | GM High Feature engine |
| Configuration: | Naturally aspirated 60° V6 |
| Block: | Cast iron |
| Head: | Aluminum |
| Valvetrain: | OHV with VVT |
| Compression: | 9.8:1 |
| Fuelsystem: | Sequential multi-port fuel injection |
| Fueltype: | Gasoline, E85 |
| Oilsystem: | Wet sump |
| Coolingsystem: | Water-cooled |
| Emissions Control: | Catalytic converter |
| Emissions Level: | California emission standards |
The High Value engine family from General Motors is a group of cam-in-block or overhead valve V6 engines. These engines feature cast iron blocks and aluminum heads, and use the same 60° vee bank as the 60° V6 family they are based on, but the new bore required offsetting the bores by away from the engine center line. These engines (aside from the LX9) are the first cam-in-block engines to implement variable valve timing, and won the 2006 Breakthrough Award from Popular Mechanics for this innovation. For the 2007 model year, the 3900 engine featured optional displacement on demand or "Active Fuel Management" which deactivates a bank of cylinders under light load to increase highway fuel economy. It was rumored that GM would produce a 3-valve design, but that never came to be. These engines were produced primarily at the GM factory in Tonawanda, New York, and at the Ramos Arizpe engine plant in Mexico.[1] The assembly line for this engine was manufactured by Hirata Corporation at its powertrain facility in Kumamoto, Japan.
As of the 2012 model year, GM no longer sells these engines in any U.S. market vehicles.
These engines should not be confused with the 3.5L DOHC LX5 (Shortstar) V6 engine.
The LX9 3500 is an OHV engine based on the 3400 V6. Bore and stroke are, for a displacement of . According to a GM press release from October 2002, the 3500 V6 offered improved performance and fuel efficiency, as well as reduced emissions and NVH compared to the 3400 V6. The 3500 V6 featured an updated powertrain control module, electronic throttle control, fuel injection system, exhaust manifold, catalytic converter, accessory drive system, and improved cooling and sealing systems.[2] Power output ranges from to, and torque ranges from to .
Applications:
The LZ4 3500 is an OHV engine that uses a block similar to the 3.9L LZ9 V6. It was introduced for the 2006 model year Impala and Monte Carlo. Bore is the same, but the stroke is reduced to for a displacement of . It includes continuously variable cam timing (fixed overlap). Output is at 5800 rpm and at 4000 rpm. Horsepower rating changed for the 2007 model year to at 5800 rpm and torque at 4000 rpm. The Chevrolet Malibu, Pontiac G6, and Saturn Aura came equipped with this engine for 2007 (previously, the Malibu and G6 had the non-VVT 3.5 L LX9). In 2008, the SAE horsepower rating was dropped to, keeping torque as is. On Pontiac G6 convertible models, horsepower was rated at .
Applications:
Note: GM often refers to this engine in its literature as a "3.5L V6 with Variable Valve Timing."
The LZE 3500 is an OHV flexible-fuel engine based on the 3.5L LZ4 V6 (it can use either plain gasoline or E85) and includes continuously variable cam timing (fixed overlap). Bore and stroke are, for a displacement of . Output is at 5800 rpm and at 4000 rpm.
Applications:
Bore and stroke are for a displacement of .
The LZ9 3900 has roller rocker arms, a variable length intake manifold, and Variable Cam Timing, a novelty on a pushrod engine. A computer-controlled plenum divider, along with the VVT cam function, improves efficiency across a broader RPM range.
It produces up to and of torque, with a wide torque curve. At least 90% of the maximum torque output is available from 1500 rpm to 5500 rpm.
Applications:
The LGD 3900 is a flexible-fuel version of the LZ9, and like its 3.5L LZE counterpart, it can run on E85, pure gasoline, or any mixture of the two. This is the last version of the 3900 V6. The LGD was not available with Active Fuel Management. Output is slightly reduced at 230 horsepower at 5700 rpm and 235 lb-ft of torque at 3200 rpm.
Applications:
The LZ8 3900 has the same Variable Cam Timing technology as the LZ9. The 2007 model year introduces the Active Fuel Management system (formerly known as Displacement on Demand), which can turn off a bank of cylinders under a light load for increased fuel economy. Output is slightly lower than the LZ9 at and . For 2008, it was replaced by the LZG 3900, a flexible-fuel version of the LZ8.
Applications:
The LZ8 was replaced by the LGD for 2009.