Abstract: A variable area venturi carburetor has a wall movable by a servo controlled by venturi-like control vacuum to vary the area and thereby change airflow capacity and fuel flow; a tapered fuel metering rod is attached to the wall and cooperates with a stationary fuel jet; during cold engine operation, a temperature responsive device progressively blocks the flow of the control vacuum as the temperature decreases, to permit higher ported manifold vacuum also acting on the servo to open the venturi wider to change the fuel metering signal while withdrawing the fuel metering rod, to provide a change in richness. Return to normal temperature causes the control vacuum to bleed the ported manifold vacuum to the control vacuum level.

Abstract: The carburetor has a fast idle cam latch to prevent movement of the cam to a normal idle speed position, upon throttle valve kick-down operation, when the temperature is below a set level, to prevent engine stalling; the latch consisting of a bimetallic leaf spring in the path of movement of a finger attached to the cam, the spring being movable out of the path of the cam finger when the temperature is above the set level.

Abstract: The carburetor has a fast idle cam that is rotated by a temperature responsive element to progressively present steps of differing radial extent into the path of closing movement of the carburetor throttle plate, during cold weather operation, to maintain the throttle plates open beyond the normal idle speed position. As the temperature increases, the cam is rotated to decrease the throttle plate opening in proportion. During cold starts, an insert is positioned against the cam to open the throttle plates wider, regardless of the rotative position of the cam, for more air and fuel flow to start. Once started, the insert is removed by a vacuum servo, and the throttle plates permitted to assume the open position dictated by the cam step engaged. SPThis is a continuation of application Ser. No. 424,134, filed Dec. 12, 1973, now abandoned.

Abstract: A fuel line for a motor vehicle engine contains a fuel flow shut-off device having a number of valves which upon lateral rollover of the vehicle and engine move to shut off fuel flow through the line, regardless of the direction of rollover.

Abstract: A carburetor has a small air passage connected to the main induction passage by a sonic flow orifice; the small passage being supplied with compressed air at all times at a pressure and volume maintaining sonic flow; a fuel supply line is connected to the orifice for a constant flow of fuel, the rate of flow being varied as a function both of throttle valve position and manifold vacuum level.

Abstract: A variable area venturi carburetor has the cold engine cranking and running circuits integrated with the venturi valve circuit, to simplify the construction as compared to known carburetors of this type in which the circuits are independent, the integration being provided by an articulated linkage moving the venturi valve in response to engine manifold vacuum changes, the carburetor having an auxiliary air and fuel passage also controlled by manifold vacuum during cold engine operation to provide controlled air and the extra fuel required for cold cranking and running, and shutting down of the extra fuel supply and opening the air supply when the engine reaches the normal operating temperature.

Abstract: The engine has a duct connecting the gases in the exhaust gas crossover passage to the intake manifold, the duct normally being closed by a valve that is opened by manifold vacuum that is modulated as a function of carburetor throttle blade opening and connected to the duct past an air-bleed device that normally is open and closed against a spring force by unmodulated manifold vacuum below a predetermined level so that the gas recirculating valve opening signal force varies directly with manifold vacuum decreases to prevent recirculation during engine idle and cruising and wide-open throttle operations while providing controlled operation in the engine accelerating range between.

Abstract: A variable area venturi type carburetor has a movable wall that varies the venturi area. A fuel flow metering valve moves with the wall and has a flow splitter land straddled by a fuel inlet port to proportion flow of fuel under pressure to opposite sides of the land, part of the flow supplying fuel tubes to discharge fuel adjacent the venturi throat, with the remaining proportion of fuel being returned to the pump, the proportions varying as a function of the position of the splitter land and the shape of the inlet port traversed by the splitter land.

Abstract: A downdraft type carburetor having a conventional idle speed air/fuel mixture channel has an air/fuel mixing chamber that mixes the idle channel air/fuel mixture with idle bypass air from the main induction passage, the mixing chamber being connected to discharge into the induction passage below the throttle valve through a nozzle containing an orifice sized with respect to a larger orifice in the air bypass passage to provide a pressure differential creating sonic flow, the nozzle extending so that the sonic flow is followed by a shock wave, the turbulence created atomizing the fuel.