Abstract: A two fluid heat exchanger adapted for utilization in an exhaust gas recirculation system of an automotive internal combustion engine to reduce the temperature level of the exhaust gas from the combustion cycle that is metered from the exhaust manifold and recycled through the combustion cycle. The heat exchanger has a generally flat configuration with a first pair of flanged dished plates forming an inner chamber and a second pair of flanged dished plates encompassing the first pair of plates to form a fluid envelope around the inner chamber. The flanges of the pairs of plates are joined together with a spacing between the walls of the pairs of plates at the opposite ends with the inner flanges having openings therethrough to communicate between the upper and lower portions of the envelope.

Abstract: A combination control valve and heat exchanger for the exhaust gas recirculated from the exhaust manifold of an internal combustion engine to the carburetor thereof wherein the combination unit is compact and adapted to be mounted on the intake manifold or a spacer plate below the carburetor. The heat exchanger has a plurality of U-shaped tubes to receive the exhaust gas and reduce the temperature level thereof before it reaches the control valve metering the quantity of exhaust gas returned to the combustion cycle.