Engine fuel vaporizer

Claim 1

An engine fuel vaporizer for use on an internal combustion engine having an intake manifold, a carburetor mounted on the intake manifold and having one or more air/fuel induction passages aligned so as to discharge an air/fuel mixture into the intake manifold, exhaust manifolding including an exhaust gas crossover passage connecting spaced parts of the exhaust manifolding and passing through the intake manifold directly beneath the carburetor induction passages, the intake and exhaust manifolding being constructed of high thermal inertia slow heat transfer material, the improvement comprising, the crossover passage being defined by a thin walled sheet metal tube of high heat transfer potential for quickly radiating and transferring the heat of exhaust gases flowing through the tube through the tube walls in all directions to the fuel in the air/fuel mixture adjacent and contiguous to the tube, the tube having a flattened midportion of a generally rectangular-like cross section providing major and minor axes and being sPaced from the walls of the intake manifold so as to be encompassed by the air/fuel mixture for maximum heat transfer therebetween, the tube extending laterally to a width comparable to the diameter of an induction passage to constitute a splash shield for the vaporization of liquid fuel and fuel vapor coming into contact therewith, the tube having bell mouth-like shaped end sections mating with essentially annular exhaust manifolding portions, the end sections converging towards the flattened tube midportion for spreading the exhaust gas flow laterally of the tube longitudinal axis for better heat transfer through the tube walls.