Edelbrock Carb Tuning

Over the last two issues, we have looked at carburetor tuning trickery, and what it takes to get your carburetor to perform. In our November issue, we looked at the time-proven Holley 4150/4160 series. Last month, we looked at the Demon carburetors from Barry Grant.

This month, we are going to take a close look at a time-honored name in the speed equipment business--Edelbrock. Ever since World War II ended 60 years ago, Edelbrock has steadfastly pursued the performance improvement of automobile and marine engines. It began with Vic Edelbrock, Sr., the man who founded the company and an industry. He passed this legacy of performance along to his son, Vic Edelbrock, Jr. Today, Vic's daughters, Camee and Christi, along with one of the most talented teams in the industry, have piloted the company into continuing greatness.

For many years, Edelbrock's core business had been intake manifolds. Today, Edelbrock offers cylinder heads, fuel-injection systems, carburetors, headers, mufflers, shock absorbers, struts, high-pressure lines, hoses, and a lot more.

Edelbrock produces two basic types of carburetors: the square-bore and the spread-bore. The square-bore is the carburetor most of us are familiar with. It has four fairly uniform throttle bores that sit on top of a square intake manifold opening. The Spread-Bore has two small primary bores and two large secondary bores, and is similar to the Rochester Quadra-Jet (factory on the '70-'71 429 Cobra Jet), Carter ThermoQuad (common on Chrysler, Plymouth, and Dodge musclecars), and the Autolite 4300D ('70-'74, 351C).

We're going to focus on the Edelbrock Square-Bore (known as the 1400 Series carburetor), and also look at the Thunder Series AVS carburetor, a more upscale performance atomizer from Edelbrock based on the 1400.

We give the Edelbrock Square-Bore carburetor a lot of credit for neatness. You can make significant changes to the Edelbrock carburetor without spilling fuel on the intake manifold. This means you can swap jets and metering rods, adjust floats, and replace gaskets without spilling a drop.

Here are the two basic types...        read full caption Here are the two basic types of Edelbrock carburetors, both based on the Carter AFB/AVS series carburetors. On the left is the 1400 Series Edelbrock Square-Bore carburetor. On the right is the Thunder Series AVS carburetor that's more upscale with black anodized hardware, Torx fasteners, and an adjustable secondary butterfly valve.

The 1400 Series Edelbrock...        read full caption The 1400 Series Edelbrock Square-Bore carburetor has a counterweighted secondary air velocity valve (butterfly) that opens when the secondaries open. Air flow through the secondary throttle bores overrides the counterweight, which allows the air velocity valve to open gradually, reducing the chance for hesitation and stumble.

The air horn removes easily...        read full caption The air horn removes easily for quick service. Just remove these screws and disconnect the linkages at the accelerator pump, choke, and secondaries.