Rochester Model B
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.