Carburetor: Description and Operation

Carburetor:

The model 1946 carburetor uses seven systems to provide an appropriate air/fuel mixture for fuel economy, driveability and reduced emissions under a wide range of conditions.

These systems are the;
- Fuel Inlet System
- Idle System
- Main Metering System
- Gradient Power Enrichment System
- Accelerator Pump System
- External Fuel Bowl Vent System
- Automatic Choke System

Three main assemblies make up the model 1946 carburetor: the air horn, main body, and throttle body. The air horn assembly contains the fuel bowl vent, the enrichment valve piston and the accelerator pump piston, cup, spring, and operating lever, as well as the choke plate, shaft, lever, housing and choke cap. The idle air bleed and the high speed bleed restrictors and main well tube are also contained in the air horn assembly.

The main body assembly contains the fuel inlet system including the needle and seat assembly, the float, the float hinge pin, and retainer. The centrally located venturi contains two venturi vacuum boosters and the main discharge passage. The accelerator pump well, passages, check ball and weight, main metering jet, enrichment valve, idle tube and hot idle compensator valve are also contained in the main body assembly. Venturi vacuum pickup tube, and manifold vacuum pickup tubes are incorporated in the main body, while the spark vacuum port pickup tube is located near the mounting flange in the throttle body assembly.

The throttle body regulates air flow through the carburetor and provides a suitable mounting flange for attachment of the carburetor to the intake manifold. The throttle plate, shaft lever and return spring assemblies regulate air flow. Also found in the throttle body are the spark vacuum port, idle transfer slot, curb idle discharge port, and the idle mixture adjusting screw.

Other features of the 1946 carburetor include a throttle solenoid positioner on non-A/C vehicles to prevent dieseling by permitting a lower idle speed when the ignition is turned off. Vehicles with A/C have a solo-kicker (a two-stage throttle kicker). The solenoid portion prevents dieseling by permitting a lower idle speed when the ignition switch is turned off. The kicker portion is vacuum and increases the engine idle speed when the A/C compressor is turned on. The A/C idle speed on the vacuum kicker portion is not adjustable. Altitude compensation for vehicles sold in high altitude areas is achieved through carburetor calibration.