Air injection system for engine exhaust gases

Abstract

Apparatus for supplying supplemental air to exhaust gases exiting exhaust ports in a wall of a cylinder head of a multi-cylinder internal combustion engine and entering runners of an exhaust manifold through runner inlet ports aligned with the respective exhaust ports. An air injection plate is interposed between the cylinder head and the manifold. The air injection plate has openings aligned and registering with the respective exhaust ports and runner inlet ports. A fitting directs the supplemental air to the air injection plate openings to combine with the exhaust gases passing from the exhaust ports to the runner inlet ports.

What is claimed is:  
     
         1 . Apparatus for supplying supplemental air to exhaust gases exiting exhaust ports in a wall of a cylinder head of a multi-cylinder internal combustion engine and entering runners of an exhaust manifold through runner inlet ports aligned with the respective exhaust ports, comprising: 
 an air injection plate interposed between the cylinder head and the manifold,    said air injection plate having openings aligned and registering with the respective exhaust ports and runner inlet ports, and    means for directing the supplemental air to the air injection plate openings to combine with the exhaust gases exiting the exhaust ports and entering the exhaust manifold through the runner inlet ports.    
     
     
         2 . The apparatus of  claim 1 , wherein said means for directing the supplemental air includes a fitting for directing air into a hole in said air injection plate, and grooves in one surface said plate extending from said hole to a plurality of the openings in said plate, said grooves defining air paths from said hole to said plurality of the openings.  
     
     
         3 . The apparatus of  claim 1 , wherein said means for directing the supplemental air to the injection plate openings includes a gasket sealing between one surface of said air injection plate and the wall of the cylinder head, said gasket provided with an aperture having a marginal edge encompassing a plurality of said openings in said plate, a chamber defined by said one surface of said plate and said wall of the cylinder head within the marginal edge of the aperture, and means for introducing supplemental air into said chamber.  
     
     
         4 . The apparatus of  claim 3 , wherein said means for introducing supplemental air into said chamber includes an air fitting carried by said exhaust manifold, said fitting opening into said chamber through a hole in said air injection plate.  
     
     
         5 . The apparatus of  claim 4 , wherein said one surface of said plate has grooves defining air paths leading from the hole in said air injection plate to said respective plurality of openings.  
     
     
         6 . The apparatus of  claim 5 , wherein said grooves have branches which open into each of said plurality of openings at a plurality of spaced points.  
     
     
         7 . The apparatus of  claim 6 , further including a second gasket sealing between a second surface of said plate and said manifold having openings aligned and registering with the openings in said plate and the runner inlet ports.