System for preheating fuel

A system for improving performance and fuel economy of an internal combustion engine having a carburetor for directing an air-fuel mixture to the engine, a fluid cooling system for cooling said engine, and a fuel supply line for directing fuel from the fuel pump to said carburetor, said system comprising:

• a heat exchanger plate assembly mounted between;
• said engine and said carburetor and including opening means therein for allowing the air-fuel mixture from the carburetor to pass therethrough into the engine;
• said heat exchanger plate assembly having a wall extending generally around said opening means;
• a first compartment formed in said exchanger plate assembly and disposed generally exteriorly of said opening means and extending therearound, said first compartment having an inlet and an outlet operatively connected to said engine cooling system for circulating relatively hot coolant fluid through said first compartment, thereby transferring heat from the engine coolant fluid to the exchanger plate assembly and to the air-fuel mixture passing through said opening means formed within said exchanger plate assembly;
• a second compartment formed in said exchanger plate assembly generally exterior of said opening means and which generally extends around said opening means;
• said second compartment lying adjacent said first compartment such that heat associated with the coolant fluid passing therethrough may be readily transferred to said second compartment;
• inlet and outlet means associated with said second compartment and operatively connected to said fuel line for routing fuel through said secondcompartment prior to its entry into said carburetor such that heat associated with said engine coolant fluid passing in said first compartment may be transferred to the gas being routed through said second compartment, whereby the heat from said engine coolant fluid acts to not only heat the gas prior to entry into the carburetor but also heats the final air-fuel mixture passing from the carburetor.