Xtreme Performance - Holley Ultra XP™ Carburetor

Introducing the Holley 4150 ALUM ULTRA XP 650 CFM in a striking Hard Black finish! These Ultra XP carburetors are designed with performance in mind, weighing up to 38% less than traditional race carbs while boasting a fuel capacity that is 20% greater. With 30 innovative features, this carburetor is truly a game changer!

The sleek Hard Core Gray™ hard coat anodized finish, combined with Black™ billet components, not only looks fantastic but also provides enhanced corrosion protection. You can also choose from a natural tumble-polished aluminum finish, with options for Black™ or Red™ metering blocks and base plates. The Aluminum Ultra XP carburetor comes in various sizes including 600, 650, 750, 850, and True 950-CFM, ensuring there's a perfect fit for your needs.

Among the exciting features of the Holley Ultra XP carburetors is the integrated idle bypass valve, which allows for precise idle adjustments while keeping the correct throttle plate to transfer slot relationship. This is particularly beneficial when using more aggressive camshafts. The high-capacity fuel bowls, offering 20% more fuel capacity, help eliminate starvation issues, while the integrated fuel shelf minimizes fuel aeration and internal baffling controls slosh. Other highlights include:

• All aluminum construction that saves 4.5 lbs - a remarkable 38% weight reduction.
• Hard Core Gray with black anodized billet aluminum metering block and booster inserts.
• Designed for drag racing, circle track, or any high horsepower engines.
• Contoured venturi inlet for balanced airflow, boosting horsepower.
• Air bleeds strategically positioned for a smoother airflow transition.
• Durable metering blocks with true gasket sealing and full adjustability.
• Dual 30cc accelerator pumps to deliver the right amount of fuel from idle to full throttle.
• Clear sight windows for easy fuel level adjustments.
• Built-in drain plug for hassle-free maintenance.
• Versatile 8AN (o-ringed) inlet threads for a variety of plumbing options.
• 4 corner idle adjustment for precise control.
• Mechanical secondaries for optimal launches off the line.
• Elongated mounting holes for compatibility with both square and large flange intakes.
• Knurled curb idle screws for easy adjustments without tools.
• Factory machined accessory mounting hole for adding a primary throttle stop.
• Stainless steel adjustable secondary link for ultimate control.
• Baseplate designed with a boss for vacuum source machining.
• Includes notched float and jet extensions.
• 100% wet-flow tested by Holley technicians to ensure it's ready to run right out of the box!

• Barrels: 4
• Billet Color: Hard Core Gray with Black
• Booster: Down Leg
• CFM: 650
• Choke: None
• Circuit: 2
• Emission Code: 3
• Finish: Hard Core Gray
• Fuel: Gasoline
• Fuel Inlet: Dual
• Material: Aluminum
• Model: 4150
• Primary Main Jet: 70
• Primary Power Valve: 6.5
• Primary Pump Nozzle Size: 32
• Product Type: Ultra XP Carburetor
• Secondaries: Mechanical
• Secondary Main Jet: 70
• Secondary Pump Nozzle Size: 32
• Supercharged Application: No
• Throttle Bore: 1.688 inch
• Venturi Size: 1.250 inch
• Warranty: Limited 90 Day

• This carburetor features a square bore flange bolt pattern, making it compatible with Holley, Edelbrock, Carter AFB, and Autolite style carburetors with a 5 3/16" x 5 5/8" bolt pattern. If your intake manifold has a spreadbore style, an adapter will be necessary for installation, similar to the Mr. Gasket #1932.