0-80812BKX Ultra XP Circle Track Aluminum Carburetor 650 CFM

Name: 0-80812BKX Ultra XP Circle Track Aluminum Carburetor 650 CFM
Brand: HOLLEY
SKU: 510-0-80812BKX
Price: 1229.95 USD
Availability: InStock

^$1,229⁹⁵

Ships on 11/03/2026

Lowest Price Guarantee

650 CFM

650 CFM
Tumble Polished w/Black

Specs:
Model: 4150UXP
CFM: 650
Barrels: 4
Throttle Bore: 1.688 inch
Venturi Size: 1.250 inch
Booster: Down Leg
Secondaries: Mechanical
Circuit: 2
Choke: None
Fuel: Gasoline
Fuel Inlet: Dual
Supercharged Application: No
Material: Aluminum
Main Body & Fuel Bowl Finish: Shiny
Billet Components Color: Black
Emission Code: 3

Calibrated for Circle Track Racing!
Holley Ultra XP carbs are 38% lighter than the original Holley HP carburetor, have more fuel capacity and 30 other new features! They're available in their Hard Core Gray hard coat anodized finish with Black billet for improved corrosion protection & also available in natural tumble-polished aluminum with Black metering blocks and base plate. The Aluminum Ultra XP Circle Track Carbs are available in 650 & 750 CFM's. These Ultra XP carburetors are specifically calibrated for Circle Track & offer new features such as anti-siphon valve in the main body; high capacity HP bowls which feature 20% more fuel capacity to eliminate starvation, integrated fuel shelf to minimize fuel aeration and internal baffling to control fuel slosh. Other features include all aluminum construction, fully tunable billet metering blocks, billet base plate, wedge floats, adjustable secondary linkage and knurled (hand adjustable) curb idle screws. Holley Ultra XP carburetors are the ultimate in square bore race carburetors!

Features:

Aluminum Construction (saves 4.5 lbs - 38% weight savings)
Anodized billet aluminum metering blocks and base plate
Calibrated specifically for use on circle track
Has a set screw in the base plate for wide open throttle stop adjustment
PTFE coated throttle shafts rides in oil impregnated bronze bushings for smooth throttle actuation
Anti-siphon valve in main body to reduce pump pullover
Contoured venturi inlet offers balanced airflow for increased horsepower
Air bleeds moved outward to allow a smoother transition of airflow from the top of the carburetor into the venture
Metering blocks feature improved durability, true gasket sealing and fully adjustable (emulsion bleeds, power valve channel restrictors & idle feed restrictors)
Integrated idle bypass valve eliminates the need for holes in throttle plates and allows for proper adjustment of idle while maintaining correct throttle plate to transfer slot relationship. Helps maintain good idle control when using radical camshafts.
Dual 30cc accelerator pumps provide the perfect amount of fuel from idle to full throttle
Fuel bowls provide 20% more fuel capacity while controlling slosh with internal baffling
Clear sight windows on both sides of bowls for easy and safe fuel level adjustments
Built in drain plug in front center of bowl provides easy access to empty contents of bowl
-08AN (O-ringed) inlet threads offer a large variety of plumbing options and can be plumbed from either side; comes from the factory with -08AN inlet fittings
4 corner idle allows you to precisely control your idle system
Internal pump passage in metering block equipped with a tunable bleed off for further tuning of accelerator pump
Knurled (hand adjustable) primary and secondary curb idle screws allow for easy idle adjustment without the use of tools
Primary throttle shaft capped to prevent entry of debris & contaminates
Factory machined accessory mounting hole for easy addition of adjustable primary throttle stop. New secondary pump cam lever designed to provide positive throttle stop on secondary side
Set up with 1:1 throttle actuation
Baseplate designed with a boss that can be consumer machined for vacuum source
Includes wedge floats
100% wet-flow tested by Holley technicians to assure it arrives ready to run!

Carburetor Technical Specifications Guide, Click Here