As 8
Argus As 8 aircraft engine
Type	Piston aircraft engine
Manufacturer	Argus Motoren

The Argus As 8 was a four-cylinder, air-cooled, inverted inline aircraft engine produced in Germany by Argus Motoren in the 1930s.

Variants

As 8A

Initial production version 71 kW (95 hp) maximum for 5 minutes, 60 kW (80 hp) continuous.

As 8B

A more powerful variant developing 101 kW (135 hp) maximum for 5 minutes, 86 kW (115 hp) continuous.

As 8R

A variant produced for sport aircraft, particularly for competition use, developing 110 kW (150 hp) for take-off. Featuring:

• Increased compression ratio, from 5.36 to 5.8
• Improved cooling by increasing the numbers of cooling fins at the cylinder head and the cylinder body
• Increasing the heat dispersing area of the pistons
• Improved crankcase and oil cooling
• Improved cylinder charging
• Modified valve timing

Applications

• Albatros L 100
• Albatros Al 101
• Arado L II (As 8A)
• Arado L IIa (As 8R)
• Baumgärtl Heliofly III
• BFW M.23
• BFW M.27
• BFW M.29
• BFW M.35
• Blohm & Voss Ha 136
• Comte AC-12 Moskito
• Darmstadt D-22
• DFS 40
• Focke-Wulf Fw 44
• Heinkel He 64
• Heinkel He 72
• Klemm L 25E
• Klemm Kl 32
• Raab-Katzenstein RK.25/32
• Ruhrtaler Ru.3

Specifications (As 8B)

Data from Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944,^[1] Argus AS-8R^[2]

General characteristics

• Type: 4-cylinder inverted air-cooled in-line piston engine
• Bore: 120 mm (4.72 in)
• Stroke: 140 mm (5.51 in)
• Displacement: 6.332 L (386.40 cu in)
• Length: 1,075 mm (42.3 in) without airscrew hub
• Width: 470 mm (18.5 in)
• Height: 731 mm (28.8 in)
• Dry weight: 116 kg (256 lb) dry

128.4 kg (283 lb) equipped

Components

• Valvetrain: Overhead valves operated by pushrods and rockers
• Fuel system: One down-draught carburretor
• Fuel type: 80 Octane Aviation gasoline
• Oil system: Pressure feed at 3–6 bar (44–87 psi)
• Cooling system: Air-cooled

Performance

• Power output:
  

• 135 PS (133 hp; 99 kW) at 2,200 rpm (5 minutes) at sea level
• 125 PS (123 hp; 92 kW) at 2,150 rpm (30 minutes) at sea level
• 115 PS (113 hp; 85 kW) at 2,090 rpm (max continuous) at sea level

• Specific power: 21.3 PS/L (0.344 hp/cu in; 15.7 kW/L)
• Compression ratio: 5.35:1
• Specific fuel consumption:
  

• 0.235 kg/PSh (0.53 lb/(hp⋅h); 0.320 kg/kWh) at maximum rpm
• 0.230 kg/PSh (0.51 lb/(hp⋅h); 0.313 kg/kWh) at maximum continuous rpm

• Oil consumption: 0.008 kg/PSh (0.018 lb/(hp⋅h); 0.011 kg/kWh) at maximum continuous rpm
• Power-to-weight ratio: 1.149 PS/kg (0.514 hp/lb; 0.845 kW/kg)
• B.M.E.P.: 7.7 atm (7.8 bar; 113 psi)