Long-Forgotten Four-Barrel: the Stromberg Aeroquad

The 1952 Stromberg Aeroquad was one of the first four-barrel carburetors in the Motor City, and it was said by many to be the best. But it didn’t survive in the marketplace.

 

 

In 1952, the four-barrel carburetor arrived on the Detroit scene. Engines were growing larger and turning faster with greater volumetric efficiency, requiring greater air and fuel flow capacity. But the traditional solution, multiple carburetors, was already proven to be costly and cumbersome. General Motors led the development of a carburetor with four intake throats in a single unit, working with three suppliers: GM’s own Rochester division, Carter Carburetor, and Bendix-Stromberg.

Cadillac chose the Rochester four-barrel, while Buick called on both Carter and Stromberg to supply four-barrel carburetors for the Series 70 Roadmaster with its big 320 cubic-inch straight eight. Buick invented the catchy trade name Airpower for the feature, claiming “extra horsepower from the air!” But naturally, there was no free lunch as additional fuel was required as well.

 

All three of the new four-barrels—the Rochester 4G, the Carter WCFB (Will Carter Four-Barrel), and the Stromberg 4A Aeroquad (above)—were of similar design. Each was assembled in three sections, throttle plate, main body, and air horn cover, with a pair of float bowls. Essentially they were doubled-up versions of the time-tested two-barrel, and they were known as compound carburetors in the vernacular. The innovation was in combining the four throats in a single, cost-effective package, and in providing progressive action from the two primary front bores to the two secondary rear bores for best performance and fuel economy. On the Aeroquad, the secondaries were calibrated to start opening once the primary throttle blades were open 35 to 42 degrees.

 

When Buick introduced its new V8 for 1953, the Stromberg and Carter four-barrels were continued on the Roadmaster, and on the 1954 Super and Roadmaster as well. In mechanic’s lore, it’s said that of the two carburetors, the Stromberg was the better unit, with superior components and machining. The Aeroquad was manufactured by the Eclipse Machine division of Bendix, producers of pressure carburetors for the aviation industry, and also the pioneers of electronic fuel injection (see our feature here). Hot rodders liked the Aeroquad, too, as Stromberg carbs were familiar territory for them. But unfortunately, the Aeroquad came at a significantly higher unit cost than the Rochester and Carter four-barrels.

As the story goes, GM purchasers tried to persuade Bendix-Stromberg to streamline its manufacturing processes to bring its prices into line, but the company declined. For ’55, Buick dropped the Aeroquad in favor of Carter and Rochester carbs, while the other automakers, including Chrysler, Ford, and the rest, also went elsewhere to fill their needs for four-barrels. Stromberg would continue to supply the auto industry, but it was now out of the four-barrel carburetor business.

 

9 thoughts on “Long-Forgotten Four-Barrel: the Stromberg Aeroquad

  1. I seem to remember old timers saying Carter carbs performed better than Strombergs during the compound carb era of the Buick Fireball straight 8. The Stromberg four barrel was double the trouble of their notorious 2 barrels. It evidently took the bean counters at Buick three years to relearn the “ABC’s” of carburetion: Always Buy Carter…

  2. In ’41 and ’42 Buick offered “Dual Compound Carburetion” (2 two barrels) on their straight eights; after the war, it was a Buick engineer named Braun, who created the four barrel carburetor in 1952, and … as you have stated, the rest is history.

    • Indeed. The idea is pretty old. When the 1932 Ford V8 was introduced, an engineer at Bohn Aluminum named David Anderson recognized that with a single-plane intake manifold, there was a distribution problem. His patent drawing for a two-plane manifold shows a carburetor with four throats.

    • Actually the compound carb setup with the two 2 barrels was better for a very long engine like the straight 8 Buick as it gave more even mixture across all the cylinders.

    • WIll Carter Four Barrel is my best information, so that’s what I went with. This has been argued forever. White Cast Four Barrel, Wrought Cast Four Barrel, etc. Model W, Carter Four Barrel is a new one for me.

  3. I can’t help but note how many commenters here are old timers who designed and worked on these parts when they were mechanical designs and not the “mysterious” electronically controlled parts of today.

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