In place of hydraulic phase shift mechanisms, the Denso system uses an electric motor in the actuator mounted axially with the inlet camshaft that spins faster than the shaft to advance the timing, and slower to retard it. Benefits claimed include better response at low engine speeds and temperatures, positive camshaft positioning for starting, and a greater adjustment range.
The three key components of GM’s variable valve timing system are a VVT-specific camshaft, a phaser assembly, and a timing cover with an integrated electric solenoid.
