The Hercules Gas Engine Co. of Evansville, Ind., is usually recognized as the major manufacturer of the Economy brand gas engines that Sears, Roebuck & Co. sold through their mail order catalogs. Sears sold Economy brand engines for over 30 years, but let's start at the beginning.
Economy brand engines first show up in the 1908 Sears catalogs. They are listed as being shipped from central Iowa, and they were built by the Waterloo Gas Engine Co., Waterloo, Iowa. Serial numbers for these engines fall between 6,000 and 10,000 and probably less than 1,000 were made for Sears, with other Waterloo engines being co-mingled in this numbers series. The 6,000 serial numbers date into 1907, so Sears was apparently selling the 'Waterloo Economy' before it ever appeared in their catalogs. Hopper-cooled engines were built in 2 HP, 4 HP, 7 HP and 10 HP sizes, and 2 HP and 4 HP tank-cooled engines were also offered. They were all half-base engines with a sub-base available.
In the spring of 1909 Sears began production of gas engines at their newly purchased Holm Machine Manufacturing Co. at Sparta, Mich. These were all hopper-cooled and were built in 2 HP, 4 HP, 6 HP, 8 HP and 10 HP sizes. Eventually, 1 HP and 1-1/2 HP sizes were also built. Their first model, the Model A, was somewhat similar in design to the Waterloo-built engines it replaced. The Model A was followed by the Model B, C, CA and CX, respectively. Each of these models were a modification of the previous one. These engines first appeared in the fall 1909 Sears catalog and were last offered in the fall 1913 Sears catalog. In all, about 36,000 of these 'Sparta Economy' engines were built. There were 32,000 built at Sparta, Mich., with the last 4,000 built at the new Hercules Gas Engine Co. at Evansville, Ind.
In 1912 the Holm Machine Manufacturing Co. was acquired by the Hercules Buggy Co. of Evansville, Ind. The Hercules Gas Engine Co. was formed and new factory buildings were constructed. In the fall of 1913, the parts, patterns, machinery, equipment (and personnel) were transported by rail from Sparta, Mich., to the new factory site at Evansville, Ind.
In January of 1914, the first of the Hercules-built Economy engines were produced in the new factory at Evansville. These new engines, the Model D, appeared in the spring 1914 catalog. The Model D was a slightly modified version of the Sparta Economy Model CX that it replaced. They were offered in 1-1/2 HP, 2-1/2 HP, 5 HP, 7 HP, 9 HP and 12 HP sizes. Over the next 15 years the E, EW, F, FW, G, H (and the re-rated S models that were introduced in 1924) were built. The early 7 HP, 9 HP and 12 HP sizes were offered in the screen-cooled style, too.
In 1928 the completely redesigned YK (kerosene) engines were introduced, and in 1930 another new design, the JK, was introduced. The JK models were built until the fall of 1933, but Sears continued to offer them in their catalogs until the spring 1935 issue. All in all, Hercules built about 150,000 Economy brand engines for Sears.
In the fall 1935 Sears catalog a new kind of Economy engine made by the Stover Manufacturing and Engine Co. of Freeport, Ill., was offered. These engines were offered in three sizes, variously rated at 1-1/2 HP, 2 HP, 3 HP, 3-1/4 HP, 4 HP and 5 HP. They are easily identified because of their signature Stover flywheels with the three teardrop holes. They were last offered in the spring 1939 catalog.
The spring 1937 catalogs announced a new line of 'Powerful New Economy Air-Cooled Gasoline Engines.' Sears had been selling Briggs & Stratton engines earlier, but now they appeared under the Economy brand with a new Economy logo. These engines were still offered in 1939 catalogs, but when the Economy brand of engines was finally discontinued is unknown to the author.
Glenn Karch is a noted authority on Hercules engines. Contact him at: 20601 Old State Road, Haubstadt, IN 47639, or e-mail at: firstname.lastname@example.org