Do the cams push the pistons?

No, the camshafts do not push the pistons directly. Instead, they control the opening and closing of the engine's valves, which allows the air-fuel mixture to enter the combustion chamber and exhaust gases to exit. The pistons are moved by the combustion process within the cylinders, which is initiated by the ignition of the air-fuel mixture. The camshaft's timing is crucial for ensuring that the valves operate in sync with the pistons' movement.