Abstract: A method is proposed for operating a four stroke diesel engine, in which method water is injected into a cylinder (2) in which a reciprocable piston (3) is arranged, and which cylinder (2) has at least one outlet (7) for conducting off exhaust gases as well as at least one intake (8) for supplying air, with the outlet (7) being closed during the exhaust stroke of the piston (3) so that the outlet (7) is already closed before the piston (3) reaches the upper idle dead center at the end of the exhaust stroke, and with water being injected into the cylinder (2) when the piston (3) is located in the region of the upper idle dead center.

Abstract: The electromagnetic valve comprises a valve housing, a valve slider and two electromagnets. The valve slider is displaceably arranged in a through-bore in the housing. The through-bore and the valve slider are provided with a hard coating in order to increase the number of switching movements.