Arrangement for heating the suction gases of an internal combustion engine

A heater for incoming fuel-air mixture to an internal combustion engine of the type that includes an intake manifold for said mixture having a bottom floor area;

• a plurality of heat conducting fins extending downward from the exterior wall of the intake manifold in the bottom floor area;
• an exhaust manifold disposed underneath the intake manifold adjacent to the finned area for conveying hot combustion products from the engine;
• a circumscribing wall surrounding the finned area and having a flanged lower face for mating engagement with a flanged opening through the wall of the exhaust manifold underneath the finned area;
• a partition clamped between the flanged faces of the circumscribing wall and the opening in the wall of the exhaust manifold for enclosing the fins in a chamber defined by the partition, the circumscribing wall, and the exterior wall of the intake manifold, the partition having an inlet port adjacent to one side of the circumscribing wall for introducing the combustion products into the chamber and an outlet port spaced from the inlet port adjacent to the opposite side of the circumscribing wall for exhausting the combustion products from the chamber;
• a projecting wall extending downward from the flanged opening into the exhaust manifold;
• and a butterfly type control valve mounted in the exhaust manifold in the way of the opening for rotation about a horizontal axis parallel to the wall between a first position and a second position, the valve when in the first position deflecting the flow of hot combustion gases through the inlet port to contact the fins for heating the intake gases and for returning the combustion products to the exhaust manifold through the outlet port, the valve when in the second position substantially blocking the opening through the wall of the exhaust manifold to prevent the combustion gases from contacting the fins, and the valve coming into close contact with the projecting wall when the valve is in one of said first and second positions for preventing leakage of the combustion products around the valve when the valve is in said position, wherein the improvement comprises:
• said partition being a thin plate and the projecting wall being formed integrally with the partition on a central portion of the under surface of said plate.