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.
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.
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.
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.
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.
smoother performance at low speeds the new carburetor has been designed
to permit a continuous fuel
flow to the engine. In conventional type carburetors, there is a distinct
transfer point when the
direction of fuel flow changes from the idle to the main metering system.
This causes a momentary
lag in fuel delivery to the engine. The Model "B" carburetor by the design
of a common passage for
both the idle and main metering systems, enjoys the smoother performance
due to this continuous fuel flow from the idle to the main metering system.
the period of engine warm-up, it is often advantageous to operate the engine
with the power mixtures, without advancing
the accelerator to the full wide-open position. By the use
of a vacuum operated power system in the new carburetor, these power mixtures
are readily available.
This is due to the ability of the power valve to function at any drop in
manifold vacuum below 5" Hg.,
regardless of the degree of throttle opening. In carburetors which employ
a mechanical operated power system, the throttle must be advanced to the
full wide open position to obtain the power mixtures.
prevent poor initial acceleration and to minimize hard starting in hot weather
the model "B" unit employs an anti-percolator type of pump plunger. When
the engine is not operating, the rise in heat from the engine manifold causes
the fuel in the pump system to percolate.