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Eye Candy for the Hot Rodder - The Stromberg 97 Carburetor

Nick Hibben - December 12, 2016

Stromberg-97.com reproduction carbs are built to original Stromberg blueprint specs, with key improvements

Stromberg-97.com reproduction carbs are built to original Stromberg blueprint specs, with key improvements

Modern fuel injection systems do a terrific job of producing horsepower and controlling emissions, but they don't have much style. For getting the gearhead's blood flowing not much compares with the look and sound of three Stromberg 97 carburetors atop a hot rod's motor.

Stromberg Gets Its Start

Stromberg was a carburetor company founded in the early years of the 20th century. After winning a major patent infringement lawsuit against Detroit rival Zenith they incorporated in Chicago in 1916. Thirteen years later the company was acquired by Bendix and relocated to South Bend, IN.

After the move they continued supplying the burgeoning Detroit auto industry, but also expanded into aviation. Over the years Stromberg developed progressively more sophisticated carburetors for aircraft engines, and it might be argued, played a big part in allied air superiority during WWII.

Stromberg and Ford

1932 saw the launch of the now famous "flathead" Ford V8. By 1934 it was using a 170 cfm Stromberg Model 40 two barrel carburetor to produce an impressive for the time 85 hp. A year later the Model 48 came out, also flowing 170 cfm, quickly followed in 1936 by the 155 cfm Model 97. This last carb was standard equipment on flatheads through early 1938 and is the model most sought after by hot rodders today.

The 97 wasn't the only Stromberg carburetor of that era though. Between 1937 and '38 the smaller Ford V8-60 engine used a 125 cfm Model 81 and V12-powered Lincolns received the 160 cfm LZ.

Carburetor Naming & Identification

This naming strategy did have some logic. Model 48 carbs took their name from the 0.048" jet diameter. They are, however, identified by a 1 1/32 stamped on the side of the fuel bowl that indicates the size of the venturi in inches. Following the same strategy, 81's are marked as such on the bowl, where they also indicate their 13/16" or 0.812" venturi.

The venturi on the Model 97 measures 31/32" or 0.969" which is where the 97 comes from. While most 97's are clearly marked as such on the side of the bowl, a few were not. These can be identified by the venturi numbers. (For the curious, L carburetors had a venturi of 1.000".)

One point to note is that the 48 and 97 use the same base, identified by the EE-1 marking, so are interchangeable. (The base on the 81 is smaller.) Some carburetors were built by Bendix in their Elmira, NY facility and are recognizable by a "1-1" rather than EE-1 cast into the base.

Replacing Holleys

Around the same time that the business with Ford was growing Stromberg began producing a replacement for the Holley 94's. These were known as Stromberg 97's Type 1. Their advantage over the Holley was that the former used a vacuum-actuated power valve while that on the Stromberg was mechanical.

Positives

  • The mechanical power valve. When using two or three carburetors, low manifold vacuum causes the diaphragm to open up prematurely, leading to an over-rich mixture.
  • Jets are easy to change with the carburetor still in place, making Strombergs easy to tune. (An attractive feature for drag racers.)
  • The throttle base is considered to have a smoother action with less tendency for the valves to stick.
  • Compared to other vintage carbs, Strombergs get much better fuel economy and often offer better midrange torque.

Downsides

  • Stromberg carburetors were designed for fuel delivery at 2-1/2 psi. That's lower than the Ford pumps supplied so to avoid flooding it's advisable to use a regulator.
  • Another troublespot is the accelerator pump. As originally manufactured, this used leather, which dries out and cracks. Replacement parts use rubber which is less authentic, but more reliable.
  • Strombergs can have icing problems in freezing wet weather.

Using Strombergs

Used as a pair, the 47's, 97's and 81's work well on smaller displacement engines. Obviously they were intended for the Ford flathead motor but today there are a number of aftermarket manifolds designed for the three bolt base. Edelbrock, Offenhauser and Weiand are three manufacturers with products. In addition, there are many plates and adapters that allow various combinations such as three carbs in what's called a three-deuce setup.

Hot rods, where Stromergs are mostly used today, look and sound better with velocity stacks on the carburetor intake. These are widely available from companies such as Muroc in heights from 4" to 11". Just don't forget to use an air filter of some kind! Alternatively, various designs of air filter housings are available from a number of companies including Speedway.

3-deuce setup on an Offenhauser intake

3-deuce setup on an Offenhauser intake

Parts & Replacements

Finding original Stromberg bodies is getting harder, and they tend to fetch quite high prices. They can be rebuilt and there are a number of aftermarket kits available. There's also a company in the UK manufacturing new Strombergs. They go by the name of Stromberg 97.

Look Good, Run Great

Whether you're restoring a Ford V8 or building a hot rod, Stromberg double barrel carburetors finish the job. While the Stromberg 97 is the best known, the 48, 81 and L have their fans too. Whichever you use, they will look and sound amazing. And if they're going in your 'rod don't forget to complete them with chrome velocity stacks!

Copper rolled edge velocity stacks by So-Cal Speed Shop

Copper rolled edge velocity stacks by So-Cal Speed Shop

X-1 setup with Stromberg 97's and velocity stacks

X-1 setup with Stromberg 97's and velocity stacks

Resources

  • Stromberg 97 - Stromberg 97 genuine carburetor parts and carburettor spares.
  • Mr Stromberg.com - specializing in Stromberg 97 / 48 / 81's.
  • 97 Heaven - currently only rebuilding carburetors.

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