VVT - Variable Valve Timing

[trinacriabob]

I have a rented Monte Carlo for the Easter weekend with a OHV V6 with VVT (variable valve timing). Both the 3500 and 3900 in the MC/Impala have VVT as of this year.

How does this system work? Is it an electronic chip? Can it be expected to function trouble free for a long time? The whole concept sounds complicated.

Care to shed light on VVT if you know it /understand it?

[Ghost Dog]

BORGWARNER LAUNCHES BREAKTHROUGH VCT TECHNOLOGY

FOR NEW FAMILY OF GM V6 ENGINES

   

Chicago, Illinois, February 2, 2005 – BorgWarner Morse TEC has begun production of its first high-volume variable cam timing (VCT) systems for a new family of General Motors V6 engines being introduced this year. This system uses a Torsional Assist™ technology instead of the conventional oil-pressure actuated approach. This new technology represents a leap to the next generation of cam phasing. The launch is BorgWarner’s first production of its VCT technology and constitutes a major step in the expansion of BorgWarner’s growing engine management business.

“This production launch is a milestone that has been years in the making, and reflects a breakthrough that will revolutionize the use of variable cam timing,” said Roger Wood, President and General Manager, BorgWarner Morse TEC. “VCT is a natural extension of our global position in the fixed timing drive market. We are delighted to provide GM, and the drivers of vehicles equipped with these new engines, with improved fuel economy, reduced emissions and enhanced performance.” This new family of sophisticated V-6 engines, which includes 3.5L and 3.9L variants, are the first mass-produced overhead valve engines to feature cam phasing in an overhead-valve engine design. Later this year, the new 3.5L and 3.9L V-6 engines will debut in the 2006 model year Chevrolet Impala, Chevrolet Monte Carlo, and Pontiac G6.

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. BorgWarner VCT technology includes devices that utilize camshaft torque as their actuation energy, in contrast to conventional phaser devices that depend on engine oil pressure for actuation.

“The Torsional Assist (TA)™ innovation that we are providing to GM is unique to BorgWarner as well as the industry. It requires fewer engine architecture changes and yields fuel and emissions benefits greater than conventional oil-pressure actuated devices,” Wood said. “The launch is another example of how BorgWarner is exceptionally positioned to engineer, manage and supply completely integrated variable cam timing systems.”

http://www.morsetec.com/rel_05b.html