VVT Systems

It’s about time…
By Brian Roberts

Variable Valve Timing (VVT) is a system in an engine that allows for control of the valve timing at any given RPM range to maximize the power, emission reduction, and miles per gallon. There is a wide variety of systems out there that achieve this and most manufacturers have their own version to promote. Each system differs from one another, but all perform the same effect of controlling the valve timing. When an engine is in operation, the intake valves open to draw in the air fuel mixture. The longer the valves are open, the greater amount of air enters the cylinder. Getting the valves to close at the precise time to fully charge the cylinder with the most air possible is the goal. Leaving the valves open too long can result in the compression stroke pushing air back out the cylinder into the intake, thus reducing the power potential. Closing the valve too early minimizes the amount of air in the cylinder and again reduces the power potential. So, valve timing is critical to the efficiency of the engine. VVT systems are installed and take care of this precision control. Here are some of the more common systems out there so you will know how they operate.