Mercedes-Benz CAMTRONIC System: How it Works / Cylinder Deactivation on the M177 Engine

The CAMTRONIC system, which is a cylinder deactivation feature found on certain Mercedes-AMG vehicles with the M177 engine. The CAMTRONIC system allows the engine to switch between eight-cylinder and four-cylinder operation to improve fuel efficiency while still providing the performance expected from a sports car. The video goes on to explain how the CAMTRONIC system functions, including the use of zero cams on certain cylinders to deactivate the valves and prevent fuel from entering the combustion chamber. The video also mentions that this feature is activated in certain driving conditions such as slippery or comfort driving mode. Overall, it is a technical video explaining the working of the CAMTRONIC system on the mentioned Mercedes-AMG cars.

Wow! This four-door coupe is clearly a sports car in which the complete performance can be called up when you press the accelerator pedal, and then the driving pleasure starts. But there's more, you can also drive this vehicle fuel efficiently. This is made possible by the CAMTRONIC system with cylinder cut-off, which is standard with the M177 engine. To switch from eight-cylinder to four-cylinder operation, a dual mass flywheel was added to the engine to prevent unwanted vibrations from being transmitted to the drivetrain. This means that the driver is not aware of the changeover and can only see via the instrument cluster whether the engine is in the 4 or 8 cylinder mode.

The CAMTRONIC system includes two actuators on each cylinder bank on the intake camshaft, shown here in blue, and two actuators on the exhaust camshaft, shown here in red. Let's take a closer look. The camshaft consists of several cam pieces on which there is a cam for actuating the valves. Let's start the engine. Here you can see how the blue cam operates the roller cam follower, this pushes the valve spring and the valve opens. In cylinders 2, 3, 5 & 8, the cylinders that are switched off, there is a so-called zero cam next to the cams. Let's take a closer look at the zero cam. To do this, we remove the housing of the actuators on the intake and exhaust camshaft and let the engine rotate a little slower.

A tappet, which is located in the actuator, extends when actuated and engages in the cam track of the cam piece. Due to the rotation of the camshaft and the shape of the cam track, a lateral force acts on the cam piece, and it moves axially. This switches over to the zero cams, as you've just seen, an elevation in the cam track ensures that the tappet is pushed back into its initial position. Here you can see very clearly that the roller cam follower is not operated and the valve remains closed. To reset the camshaft, a second tappet also moves into a corresponding cam track, and the reset takes place accordingly. The two tappets are only engaged during the actuation. When the cylinder is cut off, the valves on the outlet side are deactivated first. Here, you can see this clearly. Subsequently