Abstract: A fuel preheater and emission control device for heating fuel being supplied through a fuel conduit from a fuel supply to the engine, and thereby improving its combustion. Fuel heating is accomplished as a result of heat exchange between the fuel and engine coolant flowing in a coolant conduit. The preheater comprises a coolant tube adapted to have heated coolant flow therethrough and a fuel tube adapted to have fuel flow therethrough enroute to the engine. The fuel tube includes a coil having a plurality of convolutions extending around the exterior of the coolant tube and a downstream section extending for a substantial distance within the coolant tube. The region of the downstream section between the most downstream convolution and the location at which the downstream section enters the coolant tube is spaced from the coolant tube in a way to minimize the likelihood of vapor lock, while the downstream section assures adequate fast heating for improved cold-weather performance and emission control.

Abstract: A fuel pre-heater for an internal combustion engine consisting of a coil in the fuel line in advance of the engine carburetor with a series of coil convolutions in heat transfer contact with the engine coolant conduit intermediate the radiator and the engine block with at least one section of said fuel line passing through said coolant conduit.

Abstract: A fuel preheater for heating fuel being supplied through a fuel conduit from a fuel supply to the engine. Fuel heating is accomplished as a result of heat exchange between the fuel and engine coolant flowing in a coolant conduit. The preheater comprises a coolant tube adapted to have heated coolant flow therethrough and a fuel tube adapted to have fuel flow therethrough enroute to the engine. The fuel tube includes a coil having a plurality of convolutions extending around the exterior of the coolant tube and a downstream section extending through the coolant tube. The region of the downstream section between the most downstream convolution and the location at which the downstream section enters the coolant tube is spaced from the coolant tube in a way to minimize the likelihood of vapor lock.