Carburetor with a replaceable venturi sleeves

A carburetor for an internal combustion engine, comprising:

• a carburetor body defining open-ended parallel bores extending therethrough,
• a venturi sleeve removably positioned in each of said bores;
• said venturi sleeves each defining an annular internal open ended venturi throat for the flow therethrough of air moving from the atmosphere to an internal combustion engine, said venturi throat having a first end with an annular converging surface, a second end with an annular diverging surface, and an annular wall venturi constriction intermediate its ends constructed of a shape for generating a zone of low pressure at the venturi constriction in response to a flow of air moving through said throat from said first end through said second end;
• said carburetor body including an air inlet manifold bowl with said bores intersecting said manifold bowl;
• and
• said manifold bowl having interior concave flow director surfaces with each concave flow director surface surrounding and intersecting each of said bores, with each concave flow director surface separated from adjacent concave flow director surfaces by ridges extending between said concave flow director surfaces, said flow director surfaces being substantially coextensive with the annular inwardly converging surfaces of said venturi sleeves for substantially improving the flow of air about the first ends of the venturi throats.

A carburetor for an internal combustion engine, comprising:

• a carburetor body;
• said carburetor body including an air inlet bowl;
• said carburetor body defining at least two side-by-side parallel annular open-ended venturi throats extending therethrough and intersecting said air inlet bowl for the flow of air moving from the atmosphere through said air inlet bowl through said venturi throats to an internal combustion engine;
• said venturi throats each having a first end with an annular converging surface, a second end with an annular diverging surface, and a wall venturi constriction intermediate its ends constructed of a shape for generating a zone of low pressure in response to a flow of air moving from said air inlet bowl through said throats;
• said air inlet bowl having interior contoured flow director surfaces, with each interior contoured flow director surface surrounding and intersecting one of said venturi throats, and each flow director surface being substantially coextensive with the annular converging surface of said venturi throat smoothly directing air from the air inlet bowl into the venturi throat.

A carburetor for an internal combustion engine, comprising:

• a carburetor body defining a plurality of open-ended bores extending therethrough, and said bores each including an upper cylindrical interior portion, a lower cylindrical interior portion of larger diameter than said upper cylindrical interior portion and concentric with said upper interior cylindrical portion, and an internal shoulder means joining said upper and lower cylindrical interior portions;
• a venturi sleeve positioned in each of said bores, said venturi sleeves each having an upper outer cylindrical surface sized and shaped to match the size and shape of an upper cylindrical portion of a bore and a lower outer cylindrical surface sized and shaped to match the size and shape of a lower cylindrical portion of the bore, and external shoulder means joining said upper and lower outer cylindrical surfaces and abutting an internal shoulder means of the bore;
• alignment means formed in said lower outer cylindrical surface for engaging and aligning with an adjacent venturi sleeve;
• said venturi sleeve defining an annular internal open ended venturi passage for the flow therethrough of air moving from the atmosphere to an internal combustion engine, said venturi passage having a first end, a second end, and a wall venturi constriction intermediate its ends constructed of a shape for generating a zone of low pressure at the venturi constriction in response to a flow of air moving through said passage from said first end through said second end;
• and
• means mounted to said carburetor body for holding said venturi sleeve in said bore.

A carburetor assembly for an internal combustion engine comprising:

• a carburetor body defining four open ended venturi throats extending therethrough for the movement of air from the atmosphere toward an internal combustion engine, said venturi throats being arranged parallel to each other and in a rectangular cluster in said carburetor body, and each including an annular converging inlet surface;
• said carburetor body having an air inlet manifold bowl, with said annular converging inlet surfaces of the venturi throats intersecting said manifold bowl;
• said manifold bowl having a perimeter rim and a plurality of concave contoured interior surfaces, each of said concave contoured interior surfaces surrounding one of said venturi throats and coextensive with said annular converging inlet surfaces of said venturi throats for guiding air from said manifold bowl smoothly toward said venturi throats;
• and
• ridges extending between said concave contoured interior surfaces separating said concave contoured interior surfaces for smoothly directing air from said air inlet manifold bowl into said concave contoured interior surfaces.

A venturi sleeve for a carburetor of an internal combustion engine, comprising:

• an upper outer cylindrical surface, a lower outer cylindrical surface of a diameter larger than said upper outer cylindrical surface,
• an external annular shoulder joining said upper and lower cylindrical surfaces,
• a positioning cord formed in said lower cylindrical surface for engaging a like positioning cord of an adjacent venturi sleeve,
• an annular internal open ended venturi passage for the flow therethrough of air moving from the atmosphere, through a carburetor, toward an internal combustion engine, and
• said venturi passage having a first end, a second end and an annular wall venturi constriction intermediate its ends constructed of a shape for generating a zone of low pressure at the venturi constriction in response to a flow of air moving through said passage.

A carburetor for an internal combustion engine, comprising:

• a carburetor body defining open ended venturi throats extending therethrough for the movement of air from the atmosphere toward an internal combustion engine, said venturi throats being arranged parallel to each other and in a cluster and each including an annular converging inlet surface;
• said carburetor body having an air inlet manifold bowl with contoured interior air flow director surfaces, with said annular converging inlet surfaces of the venturi throats intersecting said air flow director surfaces;
• said air inlet manifold bowl including a perimeter rim for supporting an air filter and said contoured interior air flow director surfaces extending between said perimeter rim and each of said venturi throats and defining concave air guide surfaces, with each of said concave air guide surfaces converging toward one of said venturi throats, with each concave air guide surface surrounding a venturi throat and being coextensive with said annular converging inlet surface of its said venturi throat;
• so that the air flowing adjacent the concave air guide surfaces of the inlet manifold bowl into the venturi throats tends to follow the concave guide surfaces of said manifold bowl toward the annular converging inlet surfaces of the venturi throats substantially without an abrupt change of direction.