Variable Cam Timing
Variable Camshaft Timing (VCT) is an automobile variable valve timing technology developed by Ford. It utilizes electronically controlled hydraulic valves that direct engine oil into the camshaft phaser cavity. These oil control solenoids are bolted into the cylinder heads towards the front of the engine near the camshaft phasers. The powertrain control module (PCM) transmits a signal to the solenoids to move a valve spool that regulates the flow of oil to the phaser cavity. The phaser cavity changes the valve timing by either advancing or retarding the camshafts to allow for optimum engine performance, reduced emissions, and increased fuel efficiency.
The VCT system is used in Ford's Triton 5.4L 3-valve V8 engine; the Australian Barra 182 and 240 Inline-6s; Ford's 4.6L 3-valve V8 engine used in the 2006-present Ford Explorer and 2005-present Ford Mustang GT; and the 2.0L Zetec Inline-4 used in the 1998-2003 Ford Escort ZX2 and the Ford Contour. It was also used in 99-00 mercury cougar, and in Europe on the 1.7 Ford Puma.