Exhaust Gas RECIRCULATION (EGR) System (CAPRI II): Description

The Exhaust Gas Recirculation (EGR) system is designed to reintroduce small amounts of exhaust gases into combustion cycle, thus reducing generation of oxides of nitrogen (NOx). The amount of exhaust gas reintroduced and timing cycle are controlled by engine vacuum and temperature. Spacer entry system has EGR valve mounted on spacer block between carburetor and manifold.

A venturi vacuum amplifier is used to change a relatively weak vacuum signal in throat of carburetor to a strong manifold vacuum signal at EGR valve. A relief valve is also used to dump or cancel output EGR signal whenever venturi vacuum is equal to, or greater than manifold vacuum. This allows EGR valve to close at or near wide open throttle, when maximum engine power is required.