Secondary Metering Block

The Holley Secondary Metering Block (HLY134-131) is a vital component for carbureted engine builders and performance enthusiasts who require accurate fuel delivery across the RPM range. This metering block is designed to control fuel flow to the secondary barrels of Holley carburetors, ensuring an optimal air-fuel ratio during acceleration and high-load conditions. It is essential for preventing lean-out conditions that can lead to detonation and engine damage.

Constructed from durable aluminum, the compact design of the metering block integrates seamlessly with your carburetor's secondary fuel bowl. It allows for fine-tuning of fuel delivery without the need for a complete carburetor replacement. The modular design facilitates easy access for adjustments, making it suitable for carb tuners looking to optimize fuel curves for various engine loads and conditions.

This Holley component is particularly beneficial for owners of classic Holley 4150/4160 series carburetors, as well as those involved in street, strip, and vintage racing applications. Its lightweight design contributes to a simplified setup while ensuring the necessary hydraulic balance for reliable secondary barrel operation. Whether you're tuning for performance or restoration, this metering block is a key element in achieving your engine's potential.