Now on Exhibit: Jopson Motor

In the early 20th century, as model aviation was spreading as a hobby, there was also a growing interest in gasoline engines.  And, of course, many people attempted to make gasoline engines small enough to fit into a model airplane.  There were several successes, although none reached the production level – or the miniature size – of the Brown Jr. Motors engines in the early 1930s.

Now on exhibit in the museum gallery is one of these successful attempts, a Jopson Gasoline Motor, a four cycle, horizontal opposed type, 2 cast iron cylinders of 1 ¼” bore and 1 3/8” stroke weighing in at 7 ½ pounds.  It was designed and sold by W.G. Jopson of Manchester, England, beginning about 1910.

The Jopson 2 cylinder in-line motor, with wood prop, on wood stand.
Restored Jopson Motor. Dates c. 1910. On loan from Art Gaier.

The engine is on loan from Art Gaier.  Art spent several years restoring the engine based off of research and pictures found on the internet and through conversations with others who owned similar engines.

Technical drawing of the Jopson motor showing the inner components.
This drawing of the Jopson motor appeared in Flight Magazine around 1912. It was later re-printed in Model Aeroplanes and their Motors.

At some point in the summer, two additional engines will be exhibited along with the Jopson.  A Gamage engine, manufactured in London, and a Baby Engine, manufactured in Connecticut.  These engines will be reproductions that the museum has had commissioned – they are being made now, we’re just not sure when they will be complete.

Watch the museum’s social media sites for more information on these engines.  Even better visit the museum in person to see them for yourself!

Next up:  The Before & After of the Jopson Motor!

For more information on the National Model Aviation Museum, including our location, hours and admission fees visit:


  1. Re W.G. Jopson

    UK births and death records record that one Willian George Jopson was registered, as being born, at Ashton(-under-Lyne) during Dec. 1882. Those records also record the death of William Jopson during Dec.1942 at Ashton. Ashton is a suburb of Greater Manchester.

    Flight (March 30 1912) records one W.G. Jopson as being a member of the Manchester Aero Club.

    While it is recorded that W.G. Jopson designed the Jopson engine, it was actually made (G. Brent. Flight. March 30 1912. p293) by Messers Cook & Co of Altrincham Cheshire. This town is also a suburb of Greater Manchester.

    There is no record of one W.G. Jopson being located in London. England.

    At about this time (1913) T.W.K Clarke of Kingston-upon-Thames, Surrey was in the business of marketing components for both model aircraft and full-size aircraft: also, he sold complete airframes. It is believed that the Jopson engine appeared in his 1913 catalogue, with an asking price of £10 (probably Guineas).

    The airframe shown in Fig 144 through 146 of Model Aeroplaning. V. A. Johnson 1920 Edition with a Jopson engine installed was very likely to be by T.W.K Clarke.
    This same airframe and engine – or one identical to it – was displayed at a trade exhibition in St Petersburg (i.e. pre revolution) Russia by the Kennedy Aeronautical Company (q.v.).

    Kind Regards

    Alan Strutt. england

    1. Thank you, Alan, for your comments. I appreciate you catching the mistake of London vs. Manchester – I had mixed the Jopson and Gamage engines up. It is fixed now!

      On 8/16/2017 there’s a blog post scheduled to discuss T.W.K. Clarke’s model (the 1922 edition of the book you mentioned makes it clear that it is Clarke’s) with the engine installed.

      Thanks again and have a great day!

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