Abstract: At least one inlet channel (4) for each cylinder is developed as a filler channel in which there is a flap valve (13) turning on an axis (12). During full load operation, the flap valve (13) is in a rest position, which does not influence the flow through the inlet channel (4). During partial load operation, however, the flap valve (13) is in a working position, in which it shapes the flow in the inlet channel so unsymmetrically that at the mouth (6) of the inlet channel (4) leading into the cylinder (1) the compressed air flowing out in large quantities has a tendency toward spiral and/or turbulence-reinforcing directions. In this way, fuel preparation is improved during the partial load operation of the motor, leading to combustion with low smoke and noxious substance levels and low consumption.