The 2005 Mustang GT's new aluminum MOD (modular) V8 is a single overhead cam design using three valves (2 intake, 1 exhaust) per cylinder. Incorporated in this new engine is Ford's VCT or variable camshaft timing, which is their version of a concept that has been used successfully by Japanese automakers for years. It essentially allows for variation of the overall valve timing and can optimize power output over a wider engine RPM range. Although not as sophisticated as some other systems out there, Ford states that their VCT is far less complex and lighter than others.

Variable Camshaft Timing – Power Without Penalty

Variable camshaft timing was a key in the quest to wring more power from the Mustang’s 4.6-liter, three-valve MOD V-8 engine, while simultaneously improving efficiency and reducing emissions. VCT lets allows the valves operate at optimum points in the combustion cycle, tailored to the engine’s speed and load at that instant.

The Mustang VCT system allows up to 50 degrees of cam variation in relation to the crankshaft angle. Ford’s "dual-equal" variable cam timing design shifts timing of both the intake and exhaust valves together, with one camshaft per cylinder head. This provides all the benefits of, but creates far less complexity and adds less weight than, VCT systems that actuate the intake and exhaust valves separately.

The cams operate both sets of valves using low-profile roller-finger followers, helping reduce friction and keep the overall engine height – and thus, hood line – low. Cam position is controlled by an electronic solenoid that modulates oil pressure to advance or retard the cam timing based on input from the engine’s electronic control computer.