The 4593A-3 Marathon carburetor is a three-barrel carburetor for V8 engines, designed for maximum power and efficiency in racing applications. It features three main components: a main body assembly, a float chamber, and a metering system. The main body assembly houses the air valve, mixture control valves, the throttle plates, and vacuum ports.
The float chamber is designed to regulate the amount of fuel entering the main body assembly. It accomplishes this by using a float, which rests on top of a needle valve, set by a spring-loaded lever. When atmospheric pressure increases or decreases, the size of the opening between the lever and the float changes, allowing more or less fuel to pass into the main body.
The metering system is the last component of the 4593A-3 Marathon. It is composed of two primary parts—the primary jets, which are adjustable, and the secondary jets, which are fixed. Both jets control the amount of fuel the carburetor delivers to the engine. The primary jets allow either more fuel or less fuel to be delivered, depending on the situation, while the secondary jets help to achieve optimum idle and cruise settings.
In summary, the 4593A-3 Marathon carburetor from Barry Grant is a powerful, efficient three-barrel carburetor for V8 engines. It features a main body assembly, a float chamber, and a metering system. It is designed to deliver maximum power and performance for racing applications.