An orifice apparatus is provided which couples a vacuum advancer of a distributor associated with an engine for a vehicle with a carburetor of the engine. The orifice apparatus includes a body having an upper and a lower opening between which an isolation wall is formed in which a plurality of orifices...http://www.google.fr/patents/US4328832?utm_source=gb-gplus-shareBrevet US4328832 - Multiple throttle level orifice apparatus
