The Warner Scarab Junior was an American, five-cylinder, air-cooled, radial aero engine first produced in 1930. It was a scaled-down derivative of the seven-cylinder Warner Scarab, developing 90 hp (70 kW) against the Scarab's 110 hp (80 kW).

Applications

• Aeronca L
• Culver Dart
• Rearwin Sportster

Specifications (Warner Scarab Junior 50)

Data from FAA Type Certificate Data Sheet (TCDS).^[1]

General characteristics

• Type: Five-cylinder, air-cooled, radial piston engine
• Bore: 4.25 in (108 mm)
• Stroke: 4.25 (108 mm)
• Displacement: 301 cu in (4.93 L)
• Length: 14 in (35.5 cm)
• Height: 36.5 in (93 cm)
• Dry weight: 237 lb (107.5 kg)

Components

• Valvetrain: 1 inlet and 1 exhaust valve per cylinder
• Fuel system: 1 Holley carburetor
• Fuel type: 54 octane Avgas

Performance

• Power output: 90 hp (67 kW) at 2,050 rpm
• Compression ratio: 5.2:1
• Power-to-weight ratio: 0.38 hp/lb (0.62 kW/kg)