Exploded Views & Diagrams (Holley 94/2100)
Rebuilding Instuctions (Holley 94/AA-1)
Accelerator Pump Circuit (Holley 94/2100)
Power Circuit (Holley 94/2100)
Float Circuit (Holley 94/2100)
Main Metering System (Holley 94/2110)
Adjusting the idle mixture screws doesn’t help (Holley 94/2100)
Originally the Holley 94 (as they are commonly called) was made by the Chandler Grove company for the 1938 Ford. Soon after that Ford contracted Holley to produce the 1 barrel carburetor which lasted until 1957. The Ford carburetor type for the 94 was AA-1.We still see some of the 94's with the Chandler Grove name on the carburetor. The earliest 94's made by Holley had Ford stamped into the carburetor. Later models may have 94 stamped. Holley made many replacement carburetors for the 94 including the 2100 and 2110 carburetor. The Chandler Grove, AA-1, 94, 2100 & 2110 designated carburetors are for the most part synonymous and use the same carburetor kit with the exception of a few carburetor numbers. Be sure to match your carburetor with the correct kit.
For dual, or triple carburetor setups be sure to match the carburetors. The Holley 94 uses a power valve, which normally runs at 7.6HG. When running 2 or 3 carburetors you will need to reduce the size, or you will get too much gas at power. Typically on a tri-power this is done by changing the 7.6 power valves out in all three carburetors for 2.5 or 3.0 valves.
Holley 2110 was used on trucks and cars with hot air chokes.
Holley 2110 on automatic transmissions used a dashpot.
The bi-metallic thermostat spring in the choke control mechanism will expand when cold, loosening and unwinding its coils. When warm, it will contract, winding the coils tighter. When the engine is cold, the thermostat spring expands, holding the choke plate in the closed position.
HOLLEY AA-1
DESIGN
The Holley Carburetor Model AA-1 is a dual downdraft until designed to meet the fuel requirements of the Ford and earlier Lincoln and Mercury V-type engines. This dual carburetor contains two throttle bores, each with its own throttle plate and venturi. However, they both utilize the same carburetor air inlet. Each has its own main metering system and idle system which draw fuel from a common supply in the float chamber. Fuel metering parts for these systems have been individually flow-tested to insure proper calibration of the carburetor.
The power enrichment system is fully automatic. A vacuum operated, diaphragm type power valve supplies added fuel to both main metering systems when the load on the engine demands high power output. The acceleratoing pump incorporates a spring over-riding feature to prolong the discharge of fuel for smooth, powerful acceleration. The carburetor is fully sealed and balanced. All air bleeds and vents are supplied with filtered air from the air cleaner, giving added protection against the accumulation of foreign matter in the passages. The float chamber is vented to the carburetor air inlet, maintaining balanced pressures in the carburetor to assure proper fuel metering. Some versions of this carburetor model contain passages which provide a vacuum for control of the Holley pressure distributor.
APPLICATION
This carburetor mode is used on all 1934 through 1950 Ford passenger cars and commercial vehicles having the V-8 engine, except the 1949-1950 F-7 and F-8 trucks. It is also used on all 1939 to 1948 Mercury passenger cars and 1937 to 1948 twelve cylinder Lincolns.
The model AA-1, used on all 1934 through 1950 Ford V-8 engines except the 1949-50 F-7 and F-8 Truck, had two 15/16” venturi and a special three bolt duplex mounting flange with two 1 1/4” throttle bores. The carburetor used on the 1939-48 Mercury has the same dimensions. The 1937-41 Lincoln carburetor has two 1” venturi and a special three bolt duplex mounting flange with two 1 1/4” throttle bores. The 1941-48 Lincoln carburetor also has two 1” venturi and 1 1/4” throttle bores, but the mounting flange is a standard 1 1/4” SAE four bolt duplex type.
An almost universal impression exists that all carburetors of this model are designated as AA-1. Actually, there is one exception to this - a slightly smaller version of this carburetor model was produced for the 1937 to 1940 “60” horsepower V-8 engine. This carburetor bears the model designation AA-7/8. It has two 13/16” venturi and a special three bolt duplex mounting flange with two 1 1/16” throttle bores. In design and construction, the AA-7/8 is similar to the AA-1.
INTERCHANGEABLE PARTS BETWEEN CARBURETORS
Numbers Parts for the R-1157-1A & R-1157A are interchangeable.R-1158A – R-1157A All except the throttle body.
R-1158-1A – R-1157A All except the throttle body.
R-1284AAS – R-1157A All except the throttle body and the float bowl.