"I'm real excited about the three-valve head," says Terry Wagner, the Modular V-8/V-10 engine program department manager, and powertrain manager for the new Mustang. "It brings the base 4.6 to a whole new level, and gives 300 hp at a level never offered before." Normally, adding a second intake valve is a good way to kill low-speed performance. In order to maintain velocity, the engineers added the Charge Motion Control valve, which acts in much the same way as the old intake manifold runner controls in the '96-98 four-valve Cobras. Unlike those flaps, which were located at the intake manifold, the CMCV is located at the head and blocks flow to half of the intake valves at light loads. This increased the velocity in the port, which also creates a tumble motion to help control the combustion. At higher loads and higher speeds, the valves open to get maximum airflow.

The three-valve heads with VCT allowed engine designers to use a higher compression ratio with regular 87-octane gasoline to maximize the energy used by every drop of fuel. Intake runners with active charge motion control valves also shape each combustion event for strong, low-end torque and maximum high-rpm power.