How Variable Valve Timing (VVT) Systems Work

摘要

Variable Valve Timing (VVT) or Variable Cam Timing (VCT) is common on most newer engines. It's responsible for increased performance and fuel economy on many engines, and for the elimination of many EGR valves. Most systems are lube oil-activated, and they use a control solenoid as well as the camshaft sensor, crankshaft sensor, and PCM for control. Newer systems operate off rotational torque from the engine.