Development of Continuously Variable Valve Lift Mechanism for Improved Fuel Economy

Delphi has developed a Continuously Variable Valve Lift [CVVL] mechanism to improve spark ignition engine part throttle fuel economy through the minimization of pumping losses and reduction of cam drive torque.

The latest CVVL design is focused on meeting valve lift duration targets derived from combustion analysis at key speed and load points, reducing packaging envelope, and reducing part count for low cost. Delphi's CVVL design process, simulation used to predict performance, and hardware confirmation testing will be presented and discussed in this paper.