The system uses a torsional assist technology instead of the conventional oil-pressure actuated approach, according to BorgWarner Morse TEC president and general manager Roger Wood. “The new technology is beneficial for both overhead valve and overhead cam engines, and represents a leap to the next generation of cam phasing,” he said, adding that VCT can help improve fuel economy, reduce emissions and enhance performance.

Variable cam timing is a means of precisely controlling the flow of air into and out of an engine by allowing the camshaft to be dynamically phased relative to its crankshaft. Wood said BorgWarner VCT technology includes devices that use camshaft torque as their actuation energy, in contrast to conventional phaser devices that depend on engine oil pressure for actuation.

"The torsional assist innovation that BorgWarner is providing to GM requires fewer engine architecture changes and yields fuel and emissions benefits greater than conventional oil- pressure actuated devices,” Wood explained.

The market for camshaft phasing technology is expected to grow 500% from of 5.2 million engines in 2000 to more than 26 million engines by 2009.