The Walter Mars I was a nine-cylinder, air-cooled, radial engine for aircraft use built in Czechoslovakia in the late 1920s.

The 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.^[1]

• ANBO III
• Breda Ba.15
• DAR 4
• DAR 6
• Fizir FN
• Focke-Wulf A 33
• Letov Š-32
• SET 10

Data from Flight, July 1929.^[1]

• Type: 9-cylinder radial engine
• Bore: 105 mm (5.90 in)
• Stroke: 120 mm (4.72 in)
• Displacement: 9.352 L (570.7 cu in)
• Dry weight: 159 kg (350 lb)

• Fuel system: Zenith Type 42 carburettor; two plugs/cylinder and twin Scintilla magnetos
• Cooling system: Air-cooled
• Reduction gear: Direct drive

• Power output: 112 kW (150 hp)
• Compression ratio: 5.15:1
• Power-to-weight ratio: 0.72 kW/kg (0.43 hp/lb)

Related lists

• List of aircraft engines