Fun Facts: John Deere E and EP Engine Trivia

By Staff
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Introduced in 1937, the John Deere EP – Environment Protected – was only made in the 3 hp size.
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Front view of the John Deere EP.
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John Deere E magneto, serial no. 184111.
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James McCosh Edwards' 1923 magneto patent.

The February/March 2010 issue of Gas Engine Magazine included an excellent article by Richard Dechant on the John Deere EP engines. I would like to add some information recently obtained from the John Deere Archives. As noted in Richard’s article, the first John Deere EP, introduced in 1937, was serial no. 3433975, and a total of 978 EP engines were produced that year.

The most interesting information is what happened to the last 24 EP engines. Handwritten in ink in the original JD ledger is the following information, which shows the date of action by month/day/year, the action taken and the serial numbers of the affected engines. No explanation was given as to why engines were scrapped or placed in the bargain list.

John Deere E magnetos

What we refer to as the John Deere Model E magneto was not actually a John Deere magneto, but one developed by James  McCosh Edwards of Associated Manufacturers Co. On Oct. 18, 1923, he applied for a patent for a “Magneto Lubricating Device,” and the patent was granted on July 28, 1925, patent no. 1,547,417.

According to an article by Bill Vossler in the October/November 2015 issue of GEM, Iowa Dairy Separator Co. was established in 1898 and was then reincorporated under the Associated name in 1909. If this is so, why is the company recorded in the John Deere ledger for several years of the 1920s (starting in 1923) as Iowa Dairy in lieu of Associated? It would seem logical to have it listed as Associated. Also, Edward’s 1925 patent lists Iowa Dairy Separator as the assignee, not Associated. The magneto serial number listed for each engine is handwritten in the ledger.

Associated was sold in 1946 to Hamilton Engineering Co. of Illinois, the same year John Deere terminated Model E sales. A letter dated Sept. 30, 1936, shows a close relationship between John Deere and someone presumably at Associated. I found the letter at the John Deere Archives, and they gracefully let me copy it.

Of principle interest, the letter discusses the receipt of five magnetos from Associated that were all stamped with the same serial number, 17989, and the need to individually identify them. The letter, written by E.L. Fay at John Deere and sent to P.A. Mongerson, presumably at Associated, lays out how the magnetos will be identified with unique prefixes tying them to the specific engines on which they were installed. The engines and magnetos are identified as shown.

The letter closes with the following statement: “It is desired that the Associated Mfg. Co. have these prefixes so that their records may be corrected to the point where these magnetos will be known to have been shipped out on recent engines rather than on the serial number as originally shown as that would indicate a much older magneto than they actually are.”

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