Auxiliary fuel delivery system

Claim 1

An auxiliary fuel delivery system for an internal combustion engine having an exhaust system, an induction system including a carburetor with an air inlet and a throttle valve variably admitting a fuel-air charge to the engine cylinders through an intake manifold, and a primary fuel system delivering fuel from a fuel source to said induction system upstream of said throttle valve for mixing with air therein, said auxiliary fuel delivery system comprising means heating a supply of the fuel taken from said same source and delivering same to said induction system downstream of said throttle valve and independently of the delivery of fuel by said primary fuel system and means responsive to high power engine requirements for effecting delivery of said heated fuel upon a predetermined increase in manifold pressure, said fuel heating means heating said fuel to the vapor point prior to delivery to said induction system including a fuel conduit connected with said induction system for delivering said heated fuel to said induction system, said fuel heating means comprising an electric heating element adjacent said fuel conduit capable of heating the fuel in the fuel conduit to the vapor point and a source of electric power connected with said heating element, said heating means further comprising said fuel conduit having a portion in heat exchange relationship with a portion of the exhaust system of said engine, said portion being disposed upstream of said heating element whereby the fuel in said fuel conduit is preheated prior to delivery to said heating element, and said heating element acting in combination with said exhaust heat exchanger to further heat, if necessary, the auxiliary fuel to insure heating to the vapor point temperature.