Continental O-170

A65/O-170
A Continental A65-8F installed in a Pietenpol Air Camper
Type	Piston aero-engine
Manufacturer	Continental Motors

The Continental O-170 engine is the collective military designation for a family of small aircraft engines, known under the company designation of A50, A65, A75 and A80. The line was designed and built by Continental Motors commencing in the 1940s. It was employed as the powerplant for civil and military light aircraft.^[1]

The horizontally opposed, four-cylinder engines in this family are all identical in appearance, bore, stroke, dry weight and piston displacement. All feature a bottom-mounted updraft carburetor fuel delivery system. The higher power variants differ only in compression ratio and maximum allowable rpm, plus minor modifications. The lower power versions are fully convertible to the higher rated versions.^[1]

Design and development

In all models of this family of engines the cylinder heads are of aluminum alloy, screwed and shrunk onto steel barrels. Spark plug inserts and intake valve seats are made from aluminum-bronze alloy, while the exhaust valve seats are steel. The engines all employ hydraulic tappets which operate in aluminum guides that are machined into the crankcase. The tappets are built from four parts, a cam follower body, cup, cylinder and piston and operate with clearances of 0.03 in (1 mm) to 0.11 in (3 mm). The pushrods are steel and feature pressed-in ball ends.^[1]

Lubricating oil is delivered under pressure from the 4 US qt (4 L) oil sump to the drive bearings and the crankpins though the crankshaft. The cylinder walls and pistons are spray lubricated. Normal operating oil pressure is 35 psi, with minimum idle oil pressure 10 psi.^[1]

Variants

A50

50 hp (37 kW), Compression ratio 5.4:1, max rpm 1900, fuel consumption at cruise 3.8 US gph^[1]

A65

65 hp (48 kW), Compression ratio 6.3:1, max rpm 2300, fuel consumption at cruise 4.4 US gph. The exhaust valves have stellite faces. The pistons have three rings, although some early production A65s had four piston rings.^[1][2]

A75

75 hp (56 kW), Compression ratio 6.3:1, max rpm 2600, fuel consumption at cruise 4.8 US gph. The exhaust valves have stellite faces and the connecting rods have a 0.125 in (3 mm) hole drilled in the rod cap to improve lubrication. The pistons have three rings and smaller piston pins.^[1][2]

A80

80 hp (60 kW), Compression ratio 7.55:1, max rpm 2700, fuel consumption at cruise 5.2 US gph. The connecting rods have a 0.125 in (3 mm) hole drilled in the rod cap to improve lubrication. The pistons have five rings and smaller piston pins.^[1]

Applications

A50

• Aeronca KCA, 50C, 50TC, S50C^[3]
• Luscombe 8^[3]
• Piper J-3^[3]
• Piper J-4^[3]
• Porterfield CP50^[3]
• Porterfield CP55^[3]
• Taylorcraft BC^[3]
• Taylorcraft BCS^[3]

A65

• Aeronca S65C, S65CA^[3]
• Aeronca 65F, 65CA, New Chief^[3]
• Aeronca Champion
• Circa Reproductions Nieuport
• Ercoupe 415C^[3]
• Fisher Celebrity
• Fisher Dakota Hawk
• Helmy Aerogypt^[4]
• Interstate SIA Cadet^[3]
• Luscombe 8A^[3]
• Piper J-3^[3]
• Piper J-4A^[3]
• Porterfield CP65^[3]
• Rearwin Skyranger 165^[3]
• Smith Miniplane^[5]
• Taylorcraft BCS, BCS12, 65^[1][3]
• Tayorcraft BC, BC1265, BCT^[1][3]
• Taylorcraft L-2
• Taylorcraft Tandem^[3]
• Wolf W-11 Boredom Fighter

A75

• Culver LCA^[3]
• Luscombe 8C, 8D^[3]
• Piper J-4E^[3]
• Piper J-5^[3]
• Porterfield 75C^[3]
• Rearwin Skyranger 175^[3]
• Stinson HW75^[3]

Specifications (O-170-3 or A-65-8)

Data from Continental Aircraft Engine Operator's Manual^[2]

General characteristics

• Type: 4-cylinder air-cooled horizontally opposed aircraft piston engine
• Bore: 3.875 in (98 mm)
• Stroke: 3.625 in (92 mm)
• Displacement: 171 in³ (2.8 L)
• Length: 31 in (787 mm)
• Width: 31.5 in (800 mm)
• Height: 29 5/16 in (745 mm)
• Dry weight: 170 lb (77 kg)

Components

• Valvetrain: One intake and one exhaust valve per cylinder, pushrod-actuated.
• Fuel system: Updraft carburetor
• Fuel type: 80/87 octane avgas
• Oil system: Wet sump
• Cooling system: Air-cooled

Performance

• Power output: 65 hp (48 kW) at 2,300 rpm
• Specific power: 0.38 hp/in³ (17.1 kW/L)
• Compression ratio: 6.3:1
• Fuel consumption: 4.4 US gal/hr
• Oil consumption: maximum desirable 0.37 US quarts/hr
• Power-to-weight ratio: 0.38 hp/lb (0.62 kW/kg)

See also

Related lists

• List of aircraft engines
  

Notes

1. ^ ^{a b c d e f g h i j} Christy (1983)
2. ^ ^{a b c} Teledyne Continental Motors: Continental Aircraft Engine Operator's Manual, pages 4-5. Teledyne Continental Motors, FAA Approved December 1980. Continental Form No. X30012
3. ^ ^{a b c d e f g h i j k l m n o p q r s t u v w x y z aa} Wooden props (2008). "Fahlin Propellers". http://www.modernwoodenpropellers.com/fahlin.htm. Retrieved 2008-12-13. 
4. ^ Jackson (1974)
5. ^ Plane & Pilot: 1978 Aircraft Directory, page 153. Werner & Werner, 1978. ISBN 0-918312-00-0

References

• Christy, Joe: Engines for Homebuilt Aircraft & Ultralights, pages 43-52. TAB Books, 1983. ISBN 0830623477
• Donald, David (1995). American Warplanes of World War II. New York: Barnes & Noble Books. ISBN 0760722749. 
• Jackson, A.J. (1974). British Civil Aircraft since 1919 Volume 3. London: Putnam. ISBN 037010014X.