Patent ID: 6067949
Filing Date: 2000-05-30
Classification: F02B,F02M

Abstract:
An intake manifold for use with a downdraft carburetor of a motorcycle engine having a plurality of cylinders comprising a plenum to receive a mixture of fuel and air from the venturi of the downdraft carburetor, said plenum being in fluid communication with the plurality of cylinders of the motorcycle engine through a corresponding plurality of fuel air feed tubes, each said fuel air feed tube including a transition section and a supply section coupled to a corresponding manifold outlet port and a corresponding feed tube outlet port respectively to feed the mixture of fuel and air from the downdraft carburetor to the cylinders of the motorcycle engine, said plenum comprises a first and second side wall held in spaced relationship relative to each other by a first and second end wall, a bottom plate and a carburetor mounting plate having an aperture formed therein to receive a fuel air mixture from the downdraft carburetor wherein curvilinear transition surfaces are formed between said first side wall and said second end wall and between said second side wall and said second end wall such that said manifold outlet ports of said fuel air feed tubes disposed opposite said curvilinear transition surface control are disposed adjacent said first and second substantially vertical end walls respectively, creating a circular flow thereby facilitating the introduction of the fuel air vapor stream into said transition section of each said fuel air feed tube, each said fuel air feed tube includes a substantially cone shaped transition section adjacent said plenum and a substantially tubular elongated supply section adjacent the intake port of a corresponding cylinder on the motorcycle engine, said lower peripheral edge of each fuel feed tube is disposed at or below the upper surface of said bottom plate of said plenum at the intersection of said bottom plate and said side wall and said lower surface of said substantially cone shaped or transition section is inclined at an angle in the range of from about 0.degree. to about 15.degree. relative to said bottom plate.