Abstract: An internal-combustion engine comprising an intake system has a chamber with an intake connection and individual suction pipes which are connected with a cylinder head and which, by means of valves, lead into the individual cylinders. An air supply and air purification system is connected with the intake connection. An air guiding pipe is connected with the intake connection of the chamber, which air guiding pipe projects freely into the chamber and is arranged coaxially with respect to it. The mouth opening of the air guiding pipe extends in a plane at a right angle with respect to the lateral wall of the chamber and has an identical distance to the center axes of the individual suction pipes of a second and third cylinder of the internal-combustion engine.

Abstract: An internal-combustion engine having an intake system comprises a chamber having an intake connection and individual suction pipes which are connected with a cylinder head and which lead into the individual cylinders. The interior of the chamber is connected to a pollutant reducing system which comprises at least one of the systems, such as a housing venting system, an auxiliary-air feeding system, a fuel vapor catch system and an exhaust gas return system. An intake pipe, which projects into the chamber of the intake system, which has a mouth opening approximately in a plane between two central individual suction pipes, is fastened to the intake connection, and a pipe connection, which connects the systems of the pollutant reducing system, leads into the interior of the chamber.

Abstract: An intake system for an internal-combustion engine, having a suction manifold comprising a chamber, has an intake connection on the inflow side and several individual suction pipes on the outflow side, which suction pipes lead into a cylinder head of the internal-combustion engine and are connected with the individual cylinders. The intake connection has an air guiding device which extends approximately to a plane extending between the two center suction pipes, and a wall of the air guiding device directed toward the interior openings of the suction pipes is arranged at a distance from these openings.

Abstract: A ring-shaped duct, which is connected to a coolant circulating system, extends in a throttle valve housing in an air intake section of an internal-combustion engine. A ventilating pipe for the crankcase gases is connected to the throttle valve housing, is divided into branches in the throttle valve housing and leads into ventilating points in front of and behind the throttle valve. The coolant, which circulates in the ring-shaped duct, simultaneously prevents an icing of the throttle valve and of the ventilating points.