The High Value engine family from General Motors is a group of Cam in Block or "Overhead valve" V6 engines. They use the same 60° vee bank as the 60° V6 family they are based on, but the new 99 mm (3.90 in) bore required offsetting the bores by 1.5 mm (0.059 in) away from the engine centerline. 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 features 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 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 ^[4] at their powertrain facility in Kumamoto, Japan.

As of the 2012 model year, GM no longer sells these motors in any US market vehicles.

The LX9 3500 is an OHV engine based on the 3400 V6. It incorporates electronic throttle control. Bore and stroke is 94 mm × 84 mm (3.70 in × 3.31 in), for a displacement of 3.5 L; 213.5 cu in (3,498 cc). A GM Press Release for the 2004 Malibu described the 3500 thus: "3.5L V6, will debut in the 2004 Chevrolet Malibu. The engine offers improved performance and fuel efficiency, and runs smoother and quieter than earlier generation V6 engines. The 3500 V6 features an advanced powertrain control module, improved fuel injection system, a redesigned exhaust manifold and a new catalytic converter contribute to reduced emissions, as well as improved efficiency and performance characteristics. Improvements in cooling, sealing and the accessory drive system add to the engine's overall quality, reliability and durability." Power output ranges from 196 hp (146 kW) to 201 hp (150 kW), torque ranges from 213 lb⋅ft (289 N⋅m) to 221 lb⋅ft (300 N⋅m).

It was used in the following vehicles and model years:

The LZ4 3500 is an OHV engine that uses a similar block as the 3.9L LZ9 V6 . It was introduced for the 2006 model year and Monte Carlo. Bore is the same 99 mm (3.90 in), but the stroke is reduced to 76 mm (2.99 in) for a displacement of 3.5 L; 214.2 cu in (3,510 cc). It includes continuously variable cam timing (fixed overlap). It has a cast iron block and aluminum heads. Output is 211 hp (157 kW) at 5800 rpm and 214 lb⋅ft (290 N⋅m) at 4000 rpm. Horsepower rating changed for the 2007 model year to 224 hp (167 kW) at 5800 rpm and 220 lb⋅ft (298 N⋅m) torque at 4000 rpm. The Chevrolet Malibu, Pontiac G6, and Saturn Aura became equipped with this engine for 2007 (previously the Malibu and G6 had the non-VVT 201 hp (150 kW) 3.5 L LX9). In 2008 SAE ratings dropped the horsepower ratings to 219 hp (163 kW), keeping torque as is. On Pontiac G6 convertible models, horsepower was rated at 217 hp (162 kW).

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 15% Gasoline and 85% Ethanol, E85) and includes continuously variable cam timing (fixed overlap). It has a cast iron block and aluminum heads. Bore and stroke is 99 mm × 76 mm (3.90 in × 2.99 in), for a displacement of 3.5 L; 214.2 cu in (3,510 cc). Output is 211 hp (157 kW) at 5800 rpm and 216 lb⋅ft (293 N⋅m) at 4000 rpm.

Applications:

Bore and stroke is 99 mm × 84 mm (3.90 in × 3.31 in) for a displacement of 3.9 L; 236.8 cu in (3,880 cc).

The new LZ9 3900 features Variable Cam Timing, a new feature on a pushrod engine, roller rocker arms and has a variable length intake manifold. A computer controlled plenum divider that, along with the VVT cam function, improves efficiency across a broader RPM range.

It produces 240 hp (179 kW) and 240 lb⋅ft (325 N⋅m) torque, with a wide torque curve. 90% of the torque is available from 1500 rpm to 5500 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 233 hp (174 kW) and 240 lb⋅ft (325 N⋅m).

This engine is used in the following vehicles:

The LGD 3900 is a flexible fuel version of the LZ9, and like its 3.5 L counterpart the LZE, it can run on E85, pure gasoline or any mixture of the two. Output is identical to the LZ9.

The LZG 3900 is a flexible fuel version of the LZ8 that replaces the LZ8 in the Chevrolet Impala. It keeps the Active Fuel Management system introduced on that engine and produces a nearly identical 233 hp (174 kW) and 240 lb⋅ft (325 N⋅m).