What is VTEC?

[Dale]

VTEC stands for Variable Valve Timing and Lift Electronic Control System. It is a self-developed variable valve timing and valve lift electronic control system introduced by Honda, capable of simultaneously controlling two different aspects of valve operation: opening/closing timing and lift. VTEC can adjust the valve timing and lift appropriately based on engine parameters such as speed, load, and water temperature, ensuring the engine achieves maximum efficiency at both high and low speeds. In the VTEC system, the intake camshaft features three cam lobes, each acting on one of the three rocker arms on the rocker arm shaft. When the engine operates at low speed or under low load, the three rocker arms are not connected, allowing the left and right rocker arms to actuate the two intake valves independently, resulting in different timing and lift to create a squish effect.