Carburetor air injection system

Claim 1

A carburetor injection system for reducing the suction developed by an intake manifold and for reducing the amount of heat transferred between an intake manifold and a carburetor, comprising: a downdraft carburetor including at least one barrel: an internal combustion engine including a plurality of spaced cylinders and an intake manifold communicating with said cylinders for charging a combustible mixture of fuel and air to said cylinders; an automatic choke vlave in at least one barrel of said carburetor; a flat, substantially rectangular air injector plate sealingly positioned between a carburetor and the intake manifold and including at least two fuel passage ports through the plate, said plate having: a single auxiliary air inlet port extending through one edge of said plate and opening internally of said one edge along a part of one side of said plate which is closest to said intake manifold and said auxiliary air inlet port having a diameter between 3/64ths inch and 3/32nds inch, said diameter being non-varying throughout the length of said port; air passageway means disposed in said one side of said air injector plate for conveying auxiliary air from said air inlet port to said fuel passage ports, said air passageway means comprising: a curvilinear groove having a first semi-circular portion of uniform cross-sectioned configuration extending substantially halfway around a first one of said two fuel passage ports and also having a second semi-circular portion extending substantially halfway around a second one of said two fuel passage ports; a capillary passageway connecting said curvilinear groove with said single auxiliary air inlet port so that substantially equal lengths of said curvilinear groove lie on opposite sides of the point of intersection of said capillary passageway with said curvilinear groove to substantially equally distribute to the first and second semi-circular portions air entering said curvilinear groove from said capillary passageway; and a plurality of substantially equally spaced auxiliary air feed passageways extending radially inward from each of said semi-circular portions to communicate with the periphery of the respective fuel passage port over about 180° of the periphery of said port so that air is distributed evenly to the cylinders of said engine through said intake manifold; a flexible tubing having a first end connected to said single auxiliary air inlet port and having a second end displaced from said first end; air filter means, connected to said second end of said tubing, for filtering auxiliary air introduced into said auxiliary air inlet port through said flexible tubing; a first tar paper gasket positioned between said one side of said air injector plate and said intake manifold; a second tar paper gasket positioned between said air injector plate and said carburetor; and a throttle valve positioned in at least one barrel of said carburetor between said automatic choke valve and said air injector plate.