Walter Mars IThe Walter Mars I was a nine-cylinder, air-cooled, radial engine for aircraft use built in Czechoslovakia in the late 1920s.Design and developmentThe Mars I was the largest capacity design of a series of three similar radial engines developed by the Walter company. Common cylinders were used for the five-cylinder Walter Vega and the seven-cylinder Walter Venus, the Mars I being a nine-cylinder engine.ApplicationsANBO IIIBreda Ba.15DAR 4DAR 6Fizir FNFocke-Wulf A 33Letov Š-32SET 10Specifications