Abstract: A four-stroke internal-combustion engine for a motor vehicle having inlet and exhaust valves is provided with additional outlet valves for each cylinder, which valves are adjustable by means of an actuating device and with a throttle flap arranged in the exhaust outlet, also adjustable by means of an actuating device. The actuating devices are operated by at least one directional valve, in response to actuation of a brake switch. Braking of the internal-combustion engine occurs as a result of the opening of the additional outlet valves and a throttling of the exhaust gases during the braking operation. The braking of the internal-combustion engine is speed-dependent in that engine braking is cancelled below a minimum specified speed.

Abstract: A reciprocating piston engine with at least one working space that is radially delimited by a cylinder liner retained in a cylinder block, and with at least one cylinder head which is sealingly clamped to the top side of the cylinder block and which contains liquid-cooled control parts axially delimiting the working space on one side and channels for the working medium and the cooling medium that are sealed off with respect to each other; the cylinder head thereby includes a bottom plate and side walls and possibly partition walls and the like which act reinforcingly on the bottom plate, whereby the elastic yieldingness of the bottom plate is constructed as uniformly hard as possible within the area of the circumferential configuration of the cylinder liner by weakening the reinforcing action of these walls within certain areas.