The invention relates to a piston engine comprising an engine block that contains several cylinders. The inventive piston engine also comprises a fresh-gas supply device that is provided with several supply pipes (1) which are arranged on the cylinders and are fixed to the engine block. Said piston engine further comprises a fuel injection system that is provided with a high-pressure supply line (5) which is allocated to the cylinders. The aim of the invention is to fix the supply pipes (1) and the high-pressure supply line (5) to the engine block in a simpler manner. Holding-down clamps (7) for the supply pipes (1) are configured on the high-pressure supply line (5) in such a way that the high-pressure supply line (5) fixes the supply pipes (1) to the engine block.