Edelbrock 1905 AVS2 650 CFM 4-Barrel Carburetor Manual Choke Satin Non-EGR

Vehicle Fitment

• Universal fitment - designed for any carbureted gasoline engine using a square bore (Holley-pattern) 4-barrel intake manifold flange
• Optimally calibrated for small-block engines and select big-block engines requiring 650 CFM of airflow
• Compatible with single-plane and dual-plane intake manifolds including Edelbrock Performer, Performer EPS, Performer RPM, RPM Air-Gap, Torker II, and equivalent manifolds from other manufacturers
• Suitable for a broad range of classic American V8 applications: Chevrolet small-block and big-block, Ford small-block and FE/385-series, AMC V8, Buick, Oldsmobile, Pontiac, and Mopar V8 engines - consult Edelbrock's carburetor selector tool to confirm sizing for your specific engine displacement and build

Fitment Notes

• Square bore (Holley-pattern) flange only - will not bolt directly to Quadrajet (spread bore) intake manifolds without a spread bore adapter; confirm your intake manifold flange pattern before ordering
• Non-EGR design - not compatible with vehicles requiring an EGR (Exhaust Gas Recirculation) carburetor; intended for uncontrolled (pre-emissions or non-emissions controlled) vehicles, or closed-competition racing use per JEGS/Edelbrock emissions notes
• Manual choke - requires a choke cable and mounting bracket; does not include an electric or automatic choke; if electric choke operation is preferred, see Edelbrock #1906 (electric choke version of this carburetor)
• CFM sizing guide: 650 CFM is well-suited for small-block engines from approximately 302-400 cubic inches in street performance trim, and select big-block applications up to approximately 454-460 cubic inches depending on cam profile and intended RPM range; oversizing for lightly built engines will result in poor low-speed response and fuel economy
• Carburetor stud kits #8008 or #8024 available separately if needed for manifold mounting
• Calibration kit #1948 is available separately if alternate metering rod or jet combinations are needed for specific engine combinations

Features

• Annular flow primary boosters - the defining advancement of the AVS2 over Edelbrock's previous Performer and Thunder series carburetors; each primary venturi booster features eight equally spaced orifices arranged in a ring around the venturi throat, creating a cone-shaped spray of fuel into the airstream that is far more finely atomized than a conventional center-pull booster; this improved atomization virtually eliminates the off-idle stumble and mid-range flat spots that are characteristic of center-discharge booster carburetors, particularly on engines with aggressive camshafts or high-compression ratios
• Adjustable secondary air valves - the secondary throttle plates are governed by a calibrated spring-loaded air valve that opens progressively in proportion to airflow demand, ensuring smooth secondary engagement without bog or hesitation under hard acceleration; the secondary spring tension is adjustable to match specific engine and vehicle weight combinations
• Factory-set calibration - the #1905 ships with a baseline calibration (primary jets .101, secondary jets .098, metering rods .070 x .037, orange step-up spring at 5" Hg) optimized for typical small-block street builds; most installations run correctly with no jetting changes, and Edelbrock's metering rod and spring system allows fuel mixture fine-tuning without removing or draining the carburetor
• Two-piece design with no gaskets below the fuel level - eliminates the chronic fuel weepage common in carburetors with a base gasket under the bowl; the bowl and main body are a single casting below the fuel line, with the only joint above the fuel level where leaks are inconsequential
• Serviceable without removal - metering rods, step-up springs, jets, and needle/seat can all be accessed and replaced with the carburetor installed on the engine and without draining the fuel bowls
• Both timed and full vacuum ports - two vacuum ports allow the distributor advance to be connected to either ported (timed) vacuum for economy and OE-style advance, or manifold (full) vacuum for maximum advance at idle; both ports are present and the unused port is plugged
• Satin aluminum finish - all-aluminum construction provides significant weight savings over cast-iron OE carburetors; the satin finish is clean, durable, and suited for both resto-mod and traditional street rod builds
• Cast and machined in the USA - manufactured at Edelbrock's facility in the United States

Specifications

• Part Number: 1905
• Manufacturer: Edelbrock
• Series: AVS2 (Air Valve Secondary 2nd Generation)
• Flow Rating: 650 CFM
• Configuration: 4-Barrel
• Flange Type: Square Bore (Holley-pattern)
• Choke Type: Manual
• EGR: Non-EGR
• Finish: Satin Aluminum
• Material: Aluminum
• Primary Bore Diameter: 1.44 in
• Secondary Bore Diameter: 1.75 in
• Body Height: 3.25 in
• Booster Type: Annular Flow (8 equally spaced orifices per booster)
• Secondary Type: Air Valve (adjustable)
• Primary Jets: .101
• Secondary Jets: .098
• Metering Rods: .070 x .037
• Step-Up Spring: Orange (5" Hg)
• Vacuum Ports: Timed (ported) and full (manifold) - both included
• Ford Kickdown: No
• Country of Manufacture: USA
• Quantity: Sold individually

Included Components

• 1x Edelbrock AVS2 #1905 carburetor (factory-calibrated and assembled)
• Base gasket
• Top gasket

Product Description

The Edelbrock 1905 is the manual-choke, satin-finish version of the AVS2 650 CFM carburetor - Edelbrock's next-generation four-barrel that debuted at the 2017 SEMA Show and represents a significant step beyond the long-running Performer and Thunder Series carburetors it succeeds. The defining technical leap in the AVS2 is the annular flow primary booster, which replaces the conventional single-discharge center booster with a ring of eight equally spaced orifices that spray fuel in a uniform cone shape directly into the venturi airstream. The result is dramatically improved fuel atomization at all throttle positions, and the practical effect behind the wheel is the elimination of the off-idle stumble and mid-range flat spots that have historically required careful tuning workarounds in center-booster carburetor designs - particularly on engines with large camshafts or high compression ratios.

At 650 CFM, the #1905 sits in the sweet spot for the widest range of classic V8 street builds. It is well-matched to small-block Chevrolet, Ford, AMC, Pontiac, Oldsmobile, and Mopar V8 engines in the 302-400 cubic inch range in street performance trim, and works effectively on milder big-block combinations up to approximately 454 cubic inches depending on cam and compression. It bolts to any square bore (Holley-pattern) four-barrel intake manifold - Edelbrock's own Performer, Performer RPM, RPM Air-Gap, and Torker II are ideal companions, as are equivalent manifolds from other manufacturers. The factory calibration (.101 primary jets, .098 secondary jets, .070 x .037 metering rods, orange 5" Hg step-up spring) runs correctly on most typical street builds without any jetting changes out of the box.

Edelbrock's two-piece bowl design means there is no gasket below the fuel level and no chronic weepage at the base - a persistent annoyance with many competitor carburetors. Service is equally well-considered: jets, metering rods, step-up springs, and the needle and seat can all be accessed with the carburetor in place on the engine. For builders who want electric choke operation rather than manual, the #1906 is the electric choke variant of the same carburetor. If alternate calibration is needed for a specific engine combination, the #1948 calibration kit offers additional metering rod and spring options. The #1905 ships with base and top gaskets included.