title: Walter Atom
text: # Walter Atom
  
  The Walter Atom is an air-cooled horizontal two-cylinder engine used on light aircraft. The Atom is a Czechoslovakian engine first produced in 1934.
  
  ## Specifications (Atom)
  
  ### General characteristics
  
  * Type: Horizontally-opposed 2 cylinder air-cooled
  * Bore: 85 mm (3.35 in)
  * Stroke: 96 mm (3.78 in)
  * Displacement: 1.09 L (66.5 cu in)
  * Length: 510 mm (20.08 in)
  * Width: 815 mm (32.09 in)
  * Height: 409 mm (16.10 in)
  * Dry weight: 40 kg (88.2 lb)
  
  ### Components
  
  * Valvetrain: 1 inlet and one exhaust valve per cylinder
  * Fuel system: 2 Amal carburettors
  * Fuel type: 68 octane
  * Cooling system: air
  
  ### Performance
  
  * Power output: 21 kW (28 hp) at 3000 RPM
  * Compression ratio: 5.2:1
  * Power-to-weight ratio: 2.14 kg/kW (3.52 lb/hp) at cruise
  