the piston may have a recess when the piston approaches top dead center so that an enriched zone is formed in the lower region of the compression space which can be ignited by electrodes disposed in said lower region of the compression space application_number US 76855985 A description inside the cylinder head 1 is provided an inlet valve 3 which is coaxial with the piston and to the longitudinal axis of the cylinder to which it pertains another tubular valve 2 is provided which is coaxial with and surrounds valve 3 and acts as an outlet valve valve 3 which consists of a stem 4 and a valve head 5 is also hollow and carries a nozzle carrier 6 which is screwed in on the axis of the valve and extends from the upper end of the stem 4 into the lower region of the compression space of the pertaining cylinder in addition to fuel line 44 inside the nozzle carrier 6 is located an electric lead 41 which conducts the igniting current to the electrodes 11 located on the nozzle carrier 6 the fuel line 44 through which the first pump 42 pumps fuel to the first nozzle 10 may incorporate a valve 45 through which fuel which builds up in the line 44 upon completion of the mixture forming process may flow back into the tank the vaporizing device chamber is denoted as 43 the ignition current source as 40 the second pump and the second fuel line serving to form the ignitable mixture are not shown in the drawings inside the.