The operation of planning the surface of the pointer head. The operation improves the adhesion of the head surface to the gasket, which results in better tightness between the head and the cylinder. Collecting a much larger area of ​​the head increases the engine power. See also what to do when your pistons stick: https://www.youtube.com/watch?v=0eRQrXr1Ny8&t=3s […]