Internal combustion engine having an afterburning device

An internal combustion engine having at least one outlet passage for the exhaust of burned gases, terminating at the exterior surface of the engine and capable of being placed in communication alternatively with an afterburner and with a by-pass by-passing the afterburner, a temperature regulated control member passing the burned gases through the by-pass at high temperature and through the afterburner at low temperature, a housing being arranged on the exterior surface of the engine in the region of the outlet passage, the housing have two openings in its surface adjacent to the engine, one of which openings communicates directly with the afterburner and the other opening with the by-pass, the outlet passage widening in the direction of flow towards the exterior surface so that it encloses the openings, and the control member being arranged pivotally in the outlet passage so that it connects the outlet passage exclusively with the one opening in its first position and exclusively with the other opening in its second position.