Menasco C6S

Buccaneer
Type
National origin	United States of America
Manufacturer	Menasco Motors Company

The Menasco Buccaneer was a series of popular six-cylinder, air-cooled, in-line, inverted, aero-engines, that were manufactured by Menasco Motors Company for light general aviation and sport aircraft during the 1930s and 1940s.

The six-cylinder Menasco engines had the name Buccaneer, while the four-cylinder engines had the name Pirate. The Menasco engines came in both supercharged and normally aspirated models. The supercharged models, with the S suffix added to their designation, had superior performance at higher altitudes with a relatively small increase in dimensions and weight.

...
Wikipedia