If you’re an enthusiast (and you’re here, so you probably are), you’ve heard of Edelbrock. A leader in the game since 1938, Edelbrock has over the years expanded to six locations in California and North Carolina, and boasts a name known around the world.

Edelbrock’s product lineup includes a wide variety of products, from crate engines down to gaskets, and just about everything in between. Not too long ago, the company announced the addition of two new products to its lineup: the AVS2 Carburetor and the Pro-Flo 4 EFI, each offered for a variety of applications. Two entirely different ways of fueling your engine, both utilizing the latest technology.

We’re going to break down each product here and give you the down low to see if these products might be a fit for your project.

The Pro-Flo 4 EFI

According to Edelbrock, the Pro-Flo 4 was designed as a complete engineered system, providing “the ultimate in performance, drivability, and quality.” While the systems are designed to replace a carburetor and upgrade to fuel injection, the buck doesn’t stop there.

The Pro-Flo 4 EFI is not a throttle body injection-style EFI system. Here’s the difference: throttle body injection utilizes fuel rails and injectors mounted to the throttle body, pumping fuel into the air flow stream at the top of the plenum similar to a carburetor. This design is not ideal for high-horsepower applications, as the fuel is able to puddle and condense in the plenum of the intake manifold, causing cold-start issues. Also, the delayed fuel travel time results in delayed throttle response, causing air/fuel mixture separation. In the end, the center cylinders run richer than the outer cylinders, hurting fuel economy and performance.

Edelbrock’s new design avoids those issues, by relocating the fuel injector to the end of the runner on the included intake manifold, just before the air flow stream meets the combustion chamber. Because of this design, the intake manifold runner temperatures and length do not affect efficient mixture control. Also, the fuel injector is timed with the intake valve opening, allowing for the ultimate control, and fuel delivery efficiency. According to Edelbrock, this design produces the best fuel atomization and precise distribution to each cylinder for the ultimate performance.

The accompanying E-Tuner 4 mobile application is available free from the Google Play store, and uses a Bluetooth wireless connection to communicate with the ECU. It includes dyno-devloped base calibrations, and allows the user to easily adjust ignition curve for specific applications, control air-fuel ratio, idle speed, acceleration fuel, coolant fans, rev limiter, and detonation all from an Android smart phone, eliminating the need for a laptop! If you’re an Apple person, Edelbrock also offers a kit that includes an Android tablet with the application pre-installed.


What’s in the Box?

Included in the Pro-Flo 4 EFI kit are an Edelbrock intake manifold equipped with a 1,000 cfm throttle body, fuel rails, and individual injectors for each cylinder, as well as a plug-and-play single connection distributor designed to work specifically with Pro-Flo 4. The Pro-Flo 4 Kit is available for use with traditional 4150-style throttle bodies. Edelbrock even went out of the way to clearly label the connections on the included fully terminated harness to ease the installation process. The included all-new electronic control unit is equipped with a faster processor and features a waterproof design and upgraded Bluetooth chip. It measures only half the depth of the previous ECU, making it easier to hide beneath the dashboard.

The system also includes a two-year warranty from Edelbrock.

The Edelbrock AVS2 Carburetor


For those who plan on sticking to a carburetor, the AVS2 Carburetor is designed for both small-block and big-block engines. It features annular-flow primary boosters with calibration for improved off-idle and cruising, which also delivers improved fuel atomization, eliminating flat spots during idle.

Basically, the AVS2 was designed to help your classic engine start quicker, run smoother, and allow for better low-end throttle response – all the benefits of EFI but without the electronics. When upgrading from a traditional down-leg booster carburetor, improved fuel economy is a definite positive! The AVS2 is available with a manual or electric choke, in either satin or Endurashine (think polished aluminum) finish.

Design Features

Typical carburetors feature “downleg” boosters located in the carburetor primaries. This type of booster operates by dumping fuel into the center of the venturi. The AVS2, on the other hand, features annular boosters in the form of eight equally spaced holes in the booster rings. This allows for better fuel atomization, which eliminates flat spots between idle and part throttle. In some applications, this might also improve fuel mileage. Because the AVS2 is void of power valves, it is unaffected by engine backfires.

The AVS2’s two-piece design allows for float level adjustments and easy changing of metering rods and springs without draining fuel or the removal of the carburetor. According to Edelbrock, the AVS2 has the ability to “hold a tune,” meaning that tuning and adjustments stay unchanged, providing consistent performance. Additionally, Edelbrock’s “Qwik-Tune” Secondary Air Valve allows the limitless calibration of the secondary circuit. All adjustments can be made with hand tools. It can’t get much simpler than that!

All AVS2 Series carburetors are designed, manufactured, assembled and calibrated by Edelbrock in the USA.