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Chadwick's challenge – the first supercharger

Name: Chadwick Six Stock Runabout 1910
Brand: Chadwick

Created on October 7, 2025

Text:

Karl Ludvigsen

Photos:

Archiv Karl Ludvigsen

The conspicuous curvature required by the three-stage supercharger was clearly visible in the Chadwick training quarters for the 1908 Vanderbilt Cup - Willie Haupt was at the wheel - Chadwick Supercharger

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Photographed in 1952: Lee Sherman Chadwick reproduced for posterity the superchargers with which his racing cars of the same name competed successfully in 1908 and 1909 - Chadwick Supercharger

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In their first competitions in 1907, the Chadwicks had to make do with the standard seating position of the touring car. The drive via individually encapsulated chains was a hallmark of a high-quality automobile - Chadwick Kompressor

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Trials with a single-stage supercharger in 1907 showed sufficient increase in performance to justify the construction of a three-stage supercharger. The seating position was now more suitable for racing - Chadwick supercharger

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At least one Great Chadwick Six road car benefited from supercharging. It was equipped as a 1908 Fast Runabout, reached 100 mph and cost 6500 dollars - Chadwick supercharger

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In the years 1909-1910, Len Zengle was the main driver of the supercharged Chadwick racing car. He scored the first confirmed race win for a supercharged car - Chadwick Supercharger - at Fairmount Park on October 8, 1910

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Introduced in 1907, the Great Chadwick Six with a displacement of 11.6 liters had cast-iron cylinder pairs in a T-head design, each with its own copper water jacket. The power output was 60 hp at 2500 rpm - Chadwick supercharger

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The Great Chadwick Six Stock Runabout was neither sluggish in acceleration nor in speed. But Lee Chadwick wanted more - much more - Chadwick Supercharger

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With dimensions of 127.0 x 152.4 mm, the Chadwick six-cylinder had dual ignition - by means of a magneto ignition on the intake side and an ignition coil above the exhaust valves - Chadwick supercharger

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Lee Chadwick's drawing showed the three-stage Scirocco compressor of 1908-09, which was fed by a water-heated channel from the radiator and led to the updraft carburetor - Chadwick compressor

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A section based on Chadwick's drawing depicted the three rotors keyed to the drive shaft and the way the three separate housings were nested inside each other - Chadwick compressor

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Chadwick's drawing from December 7, 1953 showed the flywheel and the Vici leather belt that drove the compressor. A spring-supported and flanged pulley maintained the tension - Chadwick compressor

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At least one replica of the compressor was made on the basis of Chadwick's drawings. The bearings were made of simple bronze, as ball bearings were almost impossible to lubricate permanently - Chadwick compressor

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At least one replica of the compressor was made using Chadwick's drawings. The bearings were made of simple bronze, as ball bearings were difficult to lubricate permanently - Chadwick compressor

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Summary

Cubic inches were not enough for Pennsylvania's Lee Chadwick. To gain more speed and power for his namesake racing cars he adapted forced induction to create the first-ever working superchargers for his cars.

This article contains the following chapters

Weakness in starting
Searching for the extraordinary
Crowned with success
Vastly superior
Inexhaustible richness of ideas

Estimated reading time: 12min

Preview (beginning of the article)

Soon after the dawning of the Twentieth Century the French and British were experimenting with designs for forced induction for cars—but not making and using them. In America, however, a car was not only competing in speed events with a supercharged engine but also exploiting its success. Its builder had taken advantage of the remnants of Philadelphia's Searchmont Motor Company, which in 1900 acquired the rights to produce the Keystone Motor Company's tiller-steered Wagonette. In 1902 Searchmont's Spencer Trask launched its range of two-cylinder cars with double-chain drive, notable as the first American cars to have forced-feed lubrication.

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