Walter Polaris

The Walter Polaris was a Czechoslovakian three-cylinder, air-cooled radial engine for powering light aircraft that was developed in the 1930s.^[1]

Polaris
Walter Polaris
Type	Radial aero engine
National origin	Czechoslovakia
Manufacturer	Walter Aircraft Engines

Applications

• Letov Š-39
• Rearwin Junior

Engines on display

A preserved example of the Walter Polaris engine is on display at the following museum:

• Prague Aviation Museum, Kbely

Specifications (Polaris)

General characteristics

• Type: 3-cylinder radial piston engine
• Bore: 105 mm (4.13 in)
• Stroke: 120 mm (4.72 in)
• Displacement: 3.12 L (190 cu in)
• Length: 708 mm (27.9 in)
• Diameter: 926 mm (36.5 in)
• Dry weight: 72 kg (159 lb)

Components

• Valvetrain: One intake and one exhaust valve per cylinder
• Fuel system: Carburettor
• Fuel type: Petrol
• Cooling system: Air-cooled

Performance

• Power output: 44 kW (59 hp) at 1,900 rpm
• Compression ratio: 5.15:1

See also

Comparable engines

• Blackburne Thrush

Related lists

• List of aircraft engines