Electromechanical valve actuation revisited.

Thierry Morin, chairman and CEO of Valeo (www.valeo.com) says electromechanical valve actuation is--at most--16 months away from full production feasibility. "Unfortunately," he adds, "OEMs are not as ready," though Valeo has in place development contracts with a American and a European automaker. "The earliest we will see it," he says, "is 2008 in a low-volume application."

James Schwyn, Valeo's R & O director--North America, says the problems with noise and size have been largely eliminated. "The diesel-like clatter is gone," he claims, "and the system is designed to fit under current valve covers." This has been accomplished through the use of small damper springs that soften the deceleration of the valve at each end of its stroke. In addition, more sophisticated control algorithms lessen the load while still giving infinitely variable valve lift and phasing independent of piston movement. These changes also make the units able to operate in all weather conditions.

Valeo claims the system--which would be applied to the inlet valves directly--on average would reduce fuel consumption and emissions by 20%, and increase torque by the same amount. Further, not only does this system eliminate the camshafts, drive chains/belts, cam phasers, and drive gears/pulleys, it also eliminates their rotational mass, parasitic losses, and cost. "An electromechanical valve system will be more expensive at first," says Morin, "but prices will drop dramatically as volumes increase. Even in low volumes such a system is much, much less expensive than hybrid drive."

Also, though 42-volt electrical systems were designed to handle the load of just such a valve train, Schwyn says Valeo has eliminated the need by packaging an efficient OC-to-DC converter that takes the 14-volts produced by a vehicle's electrical system and steps it up to 42 volts. "You don't have to tear up the electrical architecture or heavily modify the engine to run our system," he says.--CAS