What Is Valvetronic? BMW’s Innovative Throttle System.

If one reads through the press releases of BMW, it is common to stumble upon the term Valvetronic once in a while. The term is highly technical and it is seldom explained to the masses how it works. Watch this video to understand why BMW is using it and what it actually does to our cars:

This video courtesy of Engineering Explained takes us through how the Valvetronic technology works. It is a variable valve timing system that allows for continuous and precise control over variable intake valve lift, from 0.3 to 9.7 mm (0.18mm to 9.9mm, Valvetronic II and III), and duration. Too technical? Read on.

The system works in conjunction with the independent Double VANOS system that continuously varies the timing (on both intake and exhaust camshafts). Valvetronic-equipped engines rely on the amount of valve lift for load control, rather than a butterfly valve in the intake tract. To put it simply, the “gas pedal” controls the Valvetronic hardware rather than the throttle plate in normal driving.

Cylinder heads with Valvetronic have an extra set of rocker arms. These are called intermediate arms (lift scaler) and they are in position between the valve stem and the camshaft. What they do is to pivot on a central point, by means of an extra, electronically actuated camshaft. This movement alone, without any movement of the intake camshaft, can differ the intake valves’ lift from fully open, or maximum power, to almost closed, or idle.

Check out the video for more details and drawings!