New computer-controlled valve-lift control technology for GM’s 2.5-liter Ecotec engine will debut on the 2014 Chevy Impala.
The Ecotec is a dual-overhead-cam, inline-4 configuration, so this technology will not directly transfer to the new Gen V small-block, unless GM makes a radical move to DOHC architecture. But IVLC confirms GM’s commitment to technology that can change valve timing to improve engine efficiency at different speeds, and there are methods available to use on a traditional cam-in-block design–if that’s the direction GM will take with its new V8.
Called Intake Valve Lift Control (IVLC), the technology features a new rocker arm that switches between low- and high-lift cam profiles for the intake valve. The mechanism is actuated by an oil-control valve through a dual-feed stationary hydraulic lash adjuster. The engine’s ECU selects the lift profile based on engine speed, load and other conditions. In low-lift mode, the engine pumps only enough air to meet the driver’s need–resulting in better fuel economy. At higher speeds and heavier loads, the high-lift mode provides additional power.
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