Alcohol Diaphragm

The Holley Alcohol Diaphragm (MPN 135-9) is a precision fuel system component designed for carbureted engines running on methanol or other specialty fuels. This diaphragm is essential for racers, hot rodders, and serious engine builders who demand fuel metering accuracy at the carburetor's core. It is particularly useful for those tuning competition drag cars, street-strip hybrids, or transitioning fuel-injected platforms back to carb configurations.

This Holley diaphragm ensures consistent atomization and precise fuel delivery across variable engine loads and RPM ranges. Engineered to handle the corrosive and solvency demands of methanol fuel, it regulates fuel bowl pressure by controlling the float needle valve response. This design maintains optimal fuel height in the bowl under various conditions, preventing flooding, vapor lock, and lean-out situations that could compromise performance.

Ideal for bracket racers and alcohol-fueled competition vehicles, this diaphragm integrates seamlessly into Holley carburetors without adding bulk. Its compact design weighs just 0.03 lbs, making it a lightweight option for vintage or custom engine builds where Holley carburetors are the standard choice. This component is crucial for maintaining engine longevity and performance in demanding racing environments.