| December/January 1988

Stover Engine


Clarence Criswell

Alfred Buchi

Almost immediately after the diesel engine became a reality, the concept of supercharging was advocated. Dr. Alfred J. Buchi was granted the first of many turbocharger patents already in 1905. His work as a diesel engineer took him to the famous firm of Carels Bros. in Belgium, and with Sulzer Bros., Winterthur, Switzerland. Despite the obvious potential for a turbocharged engine, Dr. Buchi was unable to convince his employer to move in this direction until 1911.

Curiously, Buchi's work went almost unnoticed in the United States. However, the French-built Rateau turbocharger was used to a limited extent during World War One in connection with high-altitude aircraft engines. About 1918, General Electric Company, functioning as the American licensee to the Rateau patents, took up this work in the U.S., concentrating their efforts primarily on aircraft turbochargers. American-built Rateau units were later used during World War Two on the Flying Fortress bombers. Most of these units were built by General Electric and Allis Chalmers.

Cheap fuel and little concern for excessive weight: horsepower ratios were major factors in the apathy of the American diesel engine manufacturers toward turbo charging. During the 1930's Buchi saw the turbocharger applied to marine diesel engines, and in this regard, German manufacturers and shipbuilders took the lead. With the outbreak of World War Two, the Elliott Company of Ridgway, Pennsylvania acquired a manufacturing license for the Buchi turbocharger designs in 1940. During the 1940-45 period, United States builders produced more turbochargers than had been built in the entire world between 1923 and 1940. In addition to marine and other applications, large numbers of Elliott-Buchi turbochargers were installed on electrical generating engines.

A purely American development was the application of turbo charging to dual fuel engines. The first company to suggest this improvement was Worthington Corporation in 1945.

Briefly, several different methods of supercharging have been used. The Buchi method utilized the exhaust gases to power a high-speed turbine- it in turn operates a blower which serves to substantially raise the intake air pressure somewhat above atmospheric. Some engines, including certain Fairbanks-Morse diesels, use a reciprocating compressor. A positive pressure blower of the Roots type has been used on GM and Buda diesels to name a couple of styles. Crosshead-type engines have been designed so that the lower end served as a huge compressor and receiver. Altering the intake valve setting to induce a greater intake air velocity, and consequently, a greater air volume has been used. A very inexpensive, although rather cumbersome method, is the concept of inertia charging by using a very long intake air pipe.