More and more racers are using E85 as a cheap alternative to race gas and now Holley has raised the bar on E85 race carbs! The popular 4150 Ultra HPs are now available with components and calibrations making them ready for ethanol. They're available in 600, 650, 750, 850 and 950 CFM and all come in exclusive Hard Core Gray hard–anodized finish – the perfect barrier to the corrosive properties of ethanol fuels.

* Requires 9.75–inch spread fuel line

• 100% Holley – Made in the U.S.A.
• 97% aluminium 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

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

6061T6 BILLET ALUMINUM METERING BLOCKS
E85 specific calibration
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
Secondary jet extensions are installed

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 4500 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 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
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
50cc secondary accelerator pump
.130" stainless needle & seats
Note: New lengthened fuel line required due to increased length of bowls

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. Helps 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
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 aluminium, some color variation may be visible on Hard Core Gray carbs.

ORIGINAL HP FEATURES
Power valve blowout protection
4-corner idle
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

Product Reviews for HO0-80845HB - HOLLEY