Stover Engines: The Cooper-Stover Junior Range

Unraveling the history of Stover engines "Down Under."

| April/May 2015

I first became interested in old stationary engines around 1998, when I was given what turned out to be a 1920 3 HP Cooper tank-cooled Type W. It was built by Stover Mfg. & Engine Co., Freeport, Illinois, and supplied to Chicago Flexible Shaft Co., Chicago, Illinois, for export to Cooper Engineering Co., Sydney, Australia. It is from the Stover Junior Range of horizontal, open crank engines produced from 1910 to 1923, and it is found in Australia as either a hopper- or tank-cooled engine.

What made me look more closely at this engine was an e-mail in July 2012 from Joe Maurer in regard to tank-cooled Type Ws in the Stover ledger records. He mentioned this in his column in the August/September 2011 Gas Engine Magazine, in which he said the following:

“A recent request from Tim Clancy of Orange, New South Wales, Australia, to look up his Stover no. W112529 started an interesting chain of events. Tim’s engine is hopper-cooled. He casually mentioned that his mate, Rod Schoonderbeek, had Stover no. W127245 that was tank-cooled. I had never heard of a 3 HP tank-cooled Type W, but the records confirmed it. There were at least three groups of Type W 3 HP tank-cooled engines, all sent to Chicago Flexible Shaft Co.”

Stover publications

I started with a look at the Stover range of Junior engines, from 2-1/5 HP to 14 HP. This information comes from a repair price list for Stover horizontal hopper-cooled engines dated effective July 1, 1925. There is no mention of the Junior Range, but I was able to confirm from C. H. Wendel’s Power in the Past Vol. 3 that the engines listed below are from this range:
Prefix W: 2-1/5 HP & 3 HP. The 2-1/5 HP was first produced on Nov. 15, 1910, and rerated to 3 HP in September 1915 by increasing the rated speed from 375 RPM to 500 RPM.
Prefix T: 4 HP and 5 HP. The 4 HP was first produced on July 26, 1910. I have no information as to when this engine was rerated to 5 HP. Were the last ones shipped to Australia in 1923 5 HP engines?
Prefix RX: 6 HP. This looks to have been released in December 1915 to replace the rerated Type X.
Prefix X: 6 HP and 8 HP. It was released as a 6 HP engine on Dec. 5, 1911, and rerated to 8 HP in December 1915.

I have not found any information on the three following engines:
Prefix U: 10 HP
Prefix RH: 12 HP
Prefix RF: 14 HP.

Of note is that the above referenced Stover publication only mentions hopper-cooled engines in the Junior Range.