The invention provides a method for easily producing an engine block for a combustion engine. The method includes: a) providing an engine block with an open water jacket opening; b) placing an insert in the water jacket opening; and c) fixing the insert in the water jacket opening by friction welding. The shape of the insert is adapted to the shape of the water jacket opening such that the insert, when being placed, at least partially closes the water jacket opening and bridges the distance between the outer wall and the cylinder wall, thereby supporting the cylinder wall against the outer wall of the engine block. An engine block produced accordingly shows the advantages of a closed deck engine block.