Quadrajet

The Quadrajet is a four-barrel carburetor manufactured by the Rochester Products Division of General Motors. It was widely used on GM vehicles, and to a lesser extent on some AMC and other manufacturer applications, from the mid-1960s through the early 1990s. Known for its versatility and fuel efficiency under light load conditions, it utilized small primary bores and larger, vacuum-operated secondary bores.

The carburetor's design incorporated a primary metering system for normal driving conditions, providing good fuel economy. When greater engine power was needed, the vacuum-operated secondary air valve opened, allowing the secondary fuel circuits to provide additional fuel and air. This design aimed to balance fuel economy with performance.

The Quadrajet was offered in various configurations, with different jetting, metering rods, and other adjustments to suit a wide range of engine sizes and performance requirements. These variations were tailored to specific vehicle applications and engine calibrations.

While highly adaptable, the Quadrajet could be complex to tune properly. Its intricate design often presented challenges in diagnosing and correcting performance issues. However, when correctly tuned, it provided a good balance of fuel economy and power, making it a popular choice for many years.