Roy McAdams of Springfield, Ohio, offered the Springfield A.1 engine (circa 1919) in kit form or completely assembled and ready to run. Two other variations offered were an opposed 2-cylinder and a 5-cylinder radial. The cost for a completed A-1 was $25.00, an A-2 Twin was $75.00 and the A-5 radial was $500.00. With a bore of 1.25″ and a stroke of 1.0″ the engines could be built to burn gasoline or “house gas” (natural gas) on spark ignition. This example indicates it was constructed for natural gas, which required supplemental oiling via oil-cups on the bearing journals.

Typically, the spark plugs were re-worked from large plugs or home built using glass tubing filled with plaster of Paris for the insulator. This engine is 4.75″-long, 4″-wide, 4.75″-high (without glow plug), and weighs 8 oz.

Exhibit added: July 1, 2008 - Last modified: March 16, 2023

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