Holley 0-4781S Double Pumper Carburetor 850 CFM 4150 Mechanical Secondaries Shiny Gasoline

Holley Double Pumper carburetors are a perfect performance upgrade for hot street cars and race vehicles. Double Pumper carburetors are an American icon when it comes to performance carburetors.

From their roots as the premier carburetor on many factory muscle cars to powering thousands of vehicles across the finish line, the Double Pumper is a great choice whether you are burning up the street or the quarter mile. The Double Pumper is designed for use on lightweight vehicles with a manual transmission or an automatic transmission with a high stall and low rear end gears.

The Double Pumper is available in a gold dichromate or tumble polished shiny finish and features dual accelerator pumps for additional fuel under initial acceleration, mechanical secondaries for great performance, dual feed fuel inlets for constant high volume fuel delivery and a manual choke for easy control of engine warm up. Don't trust your performance to just anyone, Holley is the only modular carburetor company that has been in business for over 100 years and has powered every Nascar champion since the 60's.

Features and Benefits:

• Shiny finish for good looks Optimized street/strip calibration that works out-of-the-box Manual choke (Cable driven, hand operated) for precise cold start control Mechanical secondaries for awesome tire turning performance 4 corner idle allows you to precisely control your idle system Dual accelerator pumps for additional fuel under initial acceleration Dual feed fuel inlets for constant high volume fuel delivery Intended for lightweight vehicles w/ manual trans or automatics with high stall & low gearing 100 percent wet-flow tested by Holley technicians to assure it arrives ready to run!

Associated Comments:

• This model of carburetor has the square bore flange bolt pattern. It can replace Holley, Edelbrock, Carter Afb, and Autolite style carburetors with 5 3/16 inch x 5 5/8 inch bolt pattern.
• If you have a spreadbore style intake manifold, you will need an adapter to install this carburetor. Similar to the Mr.
• Gasket #1932.

Details:

• Barrel Quantity: 4.0
• Body Color: Polished
• Body Finish: Polished
• Booster: Downleg
• Booster Design: Downleg
• CFM: 850.0
• Carburetor Material: Aluminum
• Carburetor Use: Performance and Race
• Choke Type: Manual
• Condition: New
• Cubic Feet Per Minute Rating: 850.0
• Finish: Shiny
• Flange Type: Square/4150
• Fuel Type: Gasoline
• Fuel Inlet: Dual
• Grade Type: Performance
• Linkage Attached: Yes
• Marine Approved: No
• Marine Use: No
• Material: Aluminum
• Model: 4150
• Mounting Hole Quantity: 4.0
• Primary Jet Diameter: 80.0
• Primary Main Jet: 80.0
• Primary Power Valve: 6.5
• Primary Pump Nozzle Size: 31.0
• Secondaries: Mechanical
• Secondary Main Jet: 80.0
• Secondary Pump Nozzle Size: 31.0
• Spacer Included: No
• Supercharged Application: No
• Throttle Bore: 1.750 inch
• Vacuum Ports: 1 timed (spark) port, 1 full, and 1 PCV port
• Warranty: Manufacturer's Limited 90 Day Warranty

Installation Guide: Download PDF

Installation / Product Video: Watch on YouTube

⚠️ California Proposition 65 Warning
California Residents: This product can expose you to chemicals which are known to the State of California to cause cancer or other reproductive harm. Please visit www.p65warnings.ca.gov for more information.