Holley Carburetor Float

Holley Carburetor Floats: Precision Fuel Control from a Racing Legend

When it comes to keeping a carburetor's fuel bowl at exactly the right level, the float is the unsung hero of the entire fuel delivery system. Holley has spent over a century engineering these components to withstand the harshest street, strip, and oval-track conditions — and their lineup of carburetor floats reflects that depth of expertise. Whether you're rebuilding a classic muscle car carburetor or fine-tuning a dedicated race setup, Holley's float selection covers virtually every application.

Three Materials, One Right Choice for Your Build

Not all floats are created equal, and Holley makes the material decision straightforward. Holley floats are made with three different materials: brass, Nitrophyl, or Duracon (plastic). Each serves a distinct purpose:

• Brass floats — The floats constructed of brass are designed for use with alcohol or methanol fuels. Their durable soldered construction makes them the go-to choice for dedicated race engines running exotic fuels.
• Nitrophyl floats — The Nitrophyl floats are the most common, as they are used with gasoline in naturally aspirated and blow-through forced induction systems. Nitrophyl floats are great for gasoline applications, while alcohol applications must use a brass float.
• Duracon floats — Today, most Holley carburetors are built with the Duracon float, and for the most part they are all interchangeable. These modern plastic-polymer units offer a lightweight, corrosion-resistant option for street builds.

Side-Hung vs. Center-Hung: Knowing the Difference

Holley offers both side-hung and center-hung floats for most aftermarket Holley 2- and 4-barrel carburetors. A “side-hung float” has its float arm attached to the side of the float and pivots from the side of the float bowl, while a “center-hung float” has its arm attached to the float center and pivots from the center of the float bowl. The correct style depends entirely on which fuel bowl your carburetor uses, so always verify your bowl configuration before ordering.

Specialized Floats for Racing Applications

Holley's engineering goes well beyond the basics for competitors who demand more. Center-hung floats are also available with notches for jet extensions to pick up fuel during extreme g-forces; the notched floats are available in Nitrophyl only and can be purchased with or without the jet extensions. For oval-track racers, Holley's wedged floats feature a reinforced float bracket assembly that allows more fuel to flow through the bracket — especially when using bottom-feed needles and seats. Wedged floats are designed for oval track use so the float stays open in turns. This specific geometry helps prevent fuel starvation mid-corner, where consistent fuel delivery can make or break a lap time.

Broad Compatibility Across Makes and Models

Holley carburetor float kits work with side-hung and center-hung Demon and aftermarket Holley carburetor floats, as well as many OE Holley, Ford, Chrysler, GM, Motorcraft, AMC, and Rochester marine carburetors. This wide fitment means Holley floats are a reliable replacement option not just for performance carbs, but also for a broad range of factory and marine applications. Two methods of float adjustment are provided with Holley performance carburetors depending on the style of float bowl and needle and seat assembly employed: the internal (dry) setting and the external (wet) setting. Understanding which method applies to your carburetor is key to dialing in the correct fuel level from the start.

Browse the full selection of Holley Carburetor Floats to find the exact material, style, and configuration your build requires — and explore the complete Holley brand page for the full range of fuel system components that keep your engine running at its best.