Development of a 6-Cylinder Gasoline Engine with New Variable Cylinder Management Technology

Aiming for higher output power, greater fuel economy and reduced exhaust emissions, a new V-6 3.5-liter i-VTEC Variable Cylinder Management (VCM) engine has been developed. This engine uses a cylinder-deactivation mechanism with VTEC technology that allows the number of cylinders to be controlled in three modes (three, four or all six cylinders), according to the operating conditions. This adds a four-cylinder mode to the conventional cylinder- deactivation engine. In addition to increasing the number of cylinder- deactivation modes, the new hydraulic circuits, a hydraulic pressure switching mechanism and a switchover control were also developed. These make it possible to instantaneously switch the active cylinders without impairing drivability, in the same manner as a conventional engine. The new VCM engine was mounted in a new model Accord, which not only achieved top-level power output and fuel economy for its class, but at the same time also met California's Partial Zero Emission Vehicle (PZEV) standards.