2008 GM 3.6L V6 VVT (LY7)
3.6L V6 VVT (LY7) CAR AND TRUCK ENGINE
• New Applications in 2008 Saturn VUE XR & Redline, Chevrolet Equinox Sport & Pontiac Torrent GXP,G8 and Chevrolet Malibu
New Application in 2008 Saturn VUE XR & Redline, Chevrolet Equinox Sport & Pontiac Torrent GXP and G8, and Chevrolet Malibu LT & LTZ
The 3.6L V6 VVT is available as an option on these packages. These are transverse installations, equipped with GMPT’s new 6T70 Hydra-Matic six-speed automatic transmission.
Full Description of Carryover Features
In 2007, a new high-output version of the 3.6L V6 VVT powered the new Saturn Outlook and GMC Acadia crossover sport-utility vehicles. This engine is a transverse installation, matched with GM Powertrain’s 6T75 Hydra-Matic six-speed automatic transmission and either front- or all-wheel drive. In 2008, we will continue to offer this same combination of engine/transmission for the Acadia and Outlook. In 2008, the 3.6L makes its debut in the Pontiac G8 as the base engine for this new vehicle offering.
The 3.6L V6 VVT HO generates more horsepower thanks to changes in the cylinder heads and induction system, increasing airflow through the engine. The intake ports have been reshaped to increase flow, and the intake manifold features longer runners that reduce airflow restrictions. Finally, the exhaust cams have been re-profiled to speed the flow of exhaust gas out of the engine at wide-open throttle. Maximum lift does not change, but duration increases to keep the exhaust valves open a fraction longer. Preliminary figures indicate a horsepower increase of nearly six percent compared to the previous most powerful version of the 3.6L V6 VVT.
The higher output version retains the 3.6L V6 VVT’s sophisticated variable intake system. The aluminum intake manifold has a valve in its plenum, managed by the engine control module (ECM), which opens and closes according to engine speed. At idle, the valve is open. From just past idle to mid rpm, the valve closes and effectively creates two separate plenums, each feeding the intake runners and ports for half of the cylinders. This optimizes airflow at lower engine speeds to maximize low-end torque. At higher engine speeds, the plenum plate opens, creating a single, higher-volume plenum feeding all cylinders for freer breathing and high-rev horsepower. The variable intake manifold (VIM) allows optimal airflow for a given engine speed without the compromises of a fixed-volume plenum. In combination with cam phasing, it means impressively linear torque delivery.
This higher output version of the 3.6L V6 VVT features its own comprehensive acoustic package, with a full sound-dampening cover between the cam covers. The base Saturn Outlook will be equipped with single exhaust in both front- and all-wheel drive variants. All other vehicles built with the higher-output 3.6L V6 VVT will feature dual exhaust.
The 3.6L V6 VVT is available as an option on the G6 coupe and sedan and the Saturn Aura sedan. This is a transverse installation. Accessory drive is similar to that in the Buick LaCrosse, but in the G6 and Aura the 3.6L V6 VVT will be equipped with Powertrain’s new 6T70 Hydra-Matic six-speed automatic transmission.
Smaller Pitch Timing Chain
The 3.6L V6 VVT in the Cadillac CTS has a new timing chain with a smaller pitch (7.7 mm compared to 9.5mm previously) and more links. The chain features an inverted tooth design. The smaller links engage at a lower impact speed, which decreases the noise generated. In conjunction with the new chain, the number of teeth on the sprockets is also increased, increasing the meshing frequency and further reducing noise and vibration.
The new timing chain is a running change that will occur in all of GM Powertain’s V6 VVT engines through the course of the 2007 model year.
Dual-Spray Fuel Injectors
Fuel injectors on the 3.6L V6 VVT now have two tiny spray nozzles. Developed with Bosch, the dual-spray injectors improve fuel atomization in the combustion chambers compared to single-tip injectors, allowing more complete combustion. The new injectors allow better emissions management. All 3.6L V6 VVTs except those built for the Buick LaCrosse are equipped with the dual-spray fuel injectors.
Improved Oil Pan
The oil pan on 3.6L V6 VVTs built for the Cadillac CTS, SRX and STS have been stiffened to improve powertrain rigidity and reduce vehicle vibration. The oil pan bolts to the transmission bell housing as well as the engine block, eliminating points of vibration.