Ultra HP 950 CFM XP 4BRL Double Pumper -Hard Core Grey

Holley HP Carburetors have been the standard in racing Carburetors for nearly two decades. So how do you make them better? You make them 38% lighter, increase the fuel capacity by 20% and add 30 other new features! They're available in our all–new Hard Core Gray™ hard coat anodized finish with Black™ billet for superior corrosion protection. They're also available in natural tumble–polished aluminum with your choice of Black™ or Red™ metering blocks and base plate. The Aluminum Ultra HP comes in 600, 650, 750, 850, and True 950–CFM.

*Requires 9.75–inch spread fuel line, options at the bottom of the page.

• 100% Holley – Made in the U.S.A.
• 97% aluminum construction
• 38% weight savings
• 20% more fuel bowl capacity
• 10 new fuel bowl features
• 10 new base plate features
• 6 new metering block features
• 5 new main–body features
• 1 new carburetor...Ultra HP

Features

• American Made - Materials and Assembly
• Aluminum Construction (saves 4.5 lbs - 38% weight savings)

6061T6 BILLET ALUMINUM METERING BLOCKS

• Improved durability, true gasket sealing (sealing surface integrity), bright dipped anodized for good looks and corrosion protection
• Fully adjustable (emulsion bleeds, power valve channel restrictors & idle feed restrictors). Power valve channel restrictors now machined lower in metering block for improved fuel delivery to power valve circuit
• Accelerator pump channel now internally drilled eliminating need for external plug
• Excess material removed for improved fuel capacity
• Integrated pry-point assists in disassembly from fuel bowl and mainbody preventing damage to gaskets and gasket surfaces
• New snap in place bowl vent whistle makes removal and/or replacement easier

6061T6 BILLET ALUMINUM BASE PLATES

• Improved durability, true gasket sealing, bright dipped anodized for good looks and corrosion protection
• Elongated (dual pattern) mounting holes allow fitment on intakes with square flange (Holley 4150™ style) or large flange (Holley Dominator® style)
• Dedicated race-only throttle lever with all unnecessary street attachment points & tangs removed
• 950 CFM throttle shaft comes slabbed and undercut for improved airflow
• Stainless steel adjustable secondary link. Provides choice of 1:1 or progressive secondary throttle actuation for ultimate control of secondary opening rate
• 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 throttle stop
• Throttle body and new secondary pump cam lever designed to provide positive throttle stop on secondary side. Delivers safe & reliable 90° opening and return of throttle plates while ensuring maximum airflow
• Baseplate designed with a boss that can be consumer machined for vacuum source

ALL NEW FUEL BOWL DESIGN

• Completely redesigned from the ground up for racing
• 20% more fuel capacity vs. a traditional v-bowl eliminates fuel starvation and provides consistent air/fuel ratios
• Internal baffling to help control fuel slosh and minimize float level fluctuations in hard launching or cornering situations
• Fuel shelf below the needle and seat to greatly minimize fuel aeration and promote more consistent metering
• Fuel trough designed into floor of bowl to route fuel flow directly to the jets and assist in keeping jets covered by fuel
• Clear Pyrex® sight windows on both sides of bowls for easy and safe fuel level adjustments
• (A) Built in drain plug in front center of bowl provides easy access to empty contents of bowl
• (B) Contoured entry provides smooth fuel flow directly to needle & seat
• -8AN (o-ringed) inlet threads offer a large variety of plumbing options (come standard with -8AN o-ring to -6AN male adapter and -8AN plug). Can be plumbed from either side
• Material added in key areas (needle & seat area, fuel inlet, sight window area) for added strength in the demanding race environment
• Note: New lengthened fuel line required due to increased length of bowls (see Holley p/n 34-42, 34-43, 34-44 or Earl’s p/n AT104195ERL, AT104295ERL & AT104286ERL)

UPDATED MAIN BODY DESIGN

• Air bleeds moved outward to allow a smoother transition of airflow from the top of the carburetor into the venturii
• 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. H elps maintain good idle control when using radical camshafts.
• All unnecessary mounting bosses removed for a smoother, cleaner appearance
• Contoured hex head squirter screws for streamlined airflow
• Cast in Holley HP logo for easy identification by race sanctioning bodies
• Available in 600, 650, 750, 850 and True 950 CFM
• Available tumble polished with Red™ or Black™ billet.
• Available in all new Hard Core Gray™ hard coat anodized with Black™ billet. First-ever hard coat anodizing on fuel bowls and mainbody - actually penetrates the aluminum for superior corrosion protection.
• Adjustable Throttle Stop bracket and WOT Microswitch brackets available
• Due to hard coat anodizing process on cast aluminum, some color variation may be visible on Hard Core Gray™ carbs.

ORIGINAL HP FEATURES

• Power valve blowout protection
• 4-corner idle
• 30cc GLFT accelerator pumps
• Screw-in air bleeds
• Dominator style fuel bowls allow plumbing from either side
• Symmetrical venturii bores
• Spun in boosters
• Notched floats and jet extensions
• Stainless steel throttle plates