The Fuel & Exhaust Page



Rochester Model B Carburetor

The new Rochester Products' Model "B" Carburetor as used on the Chevrolet engines, presents a number of distinct new features, features which show themselves in performance for the car owner and ease of service for the mechanic.

Foremost of the features contributing to the improved performance is the unique design of the carburetor float bowl. The new carburetor has a concentric float bowl as contrasted to an eccentric or one-sided bowl on other type units. This float bowl concentricity in conjunction with the centrally located main discharge nozzle prevents any fuel from spilling from the nozzle on road inclines. Regardless of any angle the car may assume, the fuel level is at all times below the nozzle spill point.

A second feature of the new Model "B" Carburetor is the design of the Main Well support Assembly. This design eliminates any need for an anti-percolator. This assembly contains the Main Metering Jet and Power Valve. It is attached to the Cover and is suspended in the fuel of the Float Bowl.

When the engine is not operating, the rise in heat from the engine manifold is applied to the Float Bowl, causing fuel percolation or boiling. When the main metering jet is attached directly to the Float Bowl, it allows the heat to percolate the fuel in the main passageways. As a consequence, the boiling fuel seeks escape through the main nozzle and into the engine. This often times causes difficult hot starting.

However, in the Model "B" Carburetor, the heat applied to the Float Bowl may cause minor vapors atop the fuel level but the entry to the main passageways through the main metering jet is actually insulated and surrounded by the cooler solid fuel near the bottom of the Float Bowl. This prevents any fuel percolation in the passageways.



Carter Model YF

The Model YF carburetor with hand choke is used on 4 cylinder engines. The YF carburetor has the conventional float, low speed, high speed and accelerating pump circuits, but the accelerating pump and metering rod are both vacuum and mechanically controlled through a vacuum diaphragm pump unit. This carburetor also incorporates an idle bowl vent to relieve possible hard hot start problems.





Go to Carburetor Specifications



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