Exhaust gas heated engine intake manifolding and fuel vaporizer

Claim 1

An engine fuel vaporizer for use on an internal combustion engine having an intake manifold, exhaust manifolding, and 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, the intake manifold having a number of inlet openings in one plane corresponding to the number of carburetor induction passages and aligned with the induction passages to receive an air/fuel mixture therefrom for transmittal to the engine cylinders, the intake manifold also having in other planes essentially at angles to the one plane and spaced therefrom a number of air/fuel mixture outlets from the manifold corresponding to the number of engine cylinders, the improvement comprising: a hollow thin sheet metal heat transfer tube mounted in each of the inlets and extending from the carburetor induction passage towards the manifold outlets, the intake manifold including an engine hot exhaust gas passage passing from one side of the manifold to the other, the intake manifold also including portions spaced from each other and interconnected by portions of the heat transfer tubes, the said portions passing through the exhaust gas passage whereby the gases pass around the interconnecting portions of the heat transfer tubes to transfer heat through the walls thereof to vaporize liquid fuel therein, each tube having a closed cup shaped lower end portion with bottom and side walls and a number of openings in the side walls thereof, the openings being located axially a distance above the bottom wall to form a liquid fuel dam therebetween.