This engine built by H.C. Colburn of Santa Monica, California, was a valveless engine for aviation that presumed to weigh only 900 pounds for a power development of 1,100 hp.

"Colburn and his engine"

-It has eight horizontally-opposed cylinders, in the photo with covering. They worked with two stroke cycle, hence its denomination "valveless".

-Among many virtues, It had a smooth run from 30 (?) To 6,000 rpm.

-Low fuel consumption, 60% fewer parts than its equivalent of four strokes.

-No carbon formation and no detonation even using lower octane gasoline, etc.

-In the Documentation Center of Musée de l'Air et de l'Espace (MAE) in Paris, there is a dossier with this name.