Abstract: There is disclosed an evaporation chamber for converting liquid fuel to a gaseous state prior to introducing the fuel into the carburetor. The evaporation chamber consists of an outer housing and an inner housing. The inner housing is in thermal contact with the outer housing and contains a network consisting of a stacking of steel turnings which produces a sponge like surface. Exhaust gas from the engine are introduced into an inlet port which communicates with the outer housing to heat the fuel which is injected into the inner housing.

Abstract: A fuel delivery system employs an evaporation chamber which preheats the fuel by means of exhaust gases prior to injection of the fuel into a carburetor. A solenoid valve operates to control the amount of fuel introduced into the evaporation chamber and the valve is controlled in operation by means of a selector circuit which controls the operation of the valve and hence, the flow of fuel according to the speed of the engine, the pollutant content of the exhaust gases, and the temperature at which the engine is operating at.