Carburetor - HOLLEY 6520 2-Bbl: Description

The Holley 6510-C and 6520 carburetors are "staged" dual venturi electronic feedback carburetors. The primary bore is smaller than the secondary bore. The primary side of both carburetors contains float systems, idle system, main metering system, pump system and choke system. The secondary side contains main metering system and power system. Fuel for both primary and secondaries is provided by a common fuel supply. The main metering system is incorporated within carburetor primary and secondary.

The primary main metering system provides air/fuel mixture for normal engine operation. The air/fuel mixture is controlled by a duty cycle solenoid. The control solenoids are electronically actuated by the Spark Control Computer to maintain the air/fuel ratio close to 14.7:1 during normal engine operation.

The secondary main metering circuit provides more fuel for full power operation. Both carburetors are equipped with diaphragm-type accelerator pumps to provide additional fuel for sudden acceleration. Both carburetors are equipped with electric chokes to assist cold engine starts.

A Solenoid Idle Stop (SIS) and carburetor switch inform the computer of throttle position. A wide open throttle/air conditioner cutout switch is also used on Chrysler Corp. models to cancel A/C operation during wide open throttle conditions.