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.
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.
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.
Lubricating oil is delivered under pressure from the 4 US qt (3.79 L) oil sump to the drive bearings and the crankpins through the crankshaft. The cylinder walls and pistons are spray lubricated. Normal operating oil pressure is 35 psi, with minimum idle oil pressure 10 psi.
A5050 hp (37 kW),
Compression ratio 5.4:1, max rpm 1,900, fuel consumption at cruise 3.8 US gph
A50-1A50-2A50-3A50-4A50-5A50-6A50-7A6565 hp (48 kW), Compression ratio 6.3:1, max rpm 2,300, 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.
A65-1A65-2A65-3A65-4A65-5A65-6A65-7A65-8A65-8FA65-9:
A65-85?
A7575 hp (56 kW), Compression ratio 6.3:1, max rpm 2,600, 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.
A75-1A75-2A75-3A75-4A75-5A75-6A75-14A8080 hp (60 kW), Compression ratio 7.55:1, max rpm 2,700, 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.
A80-1A80-2A80-3A80-4A80-5A80-6A80-8O-170Military designation for the A50, A65, A75, A80 family of engines.
O-170-1O-170-3O-170-5O-170-7A50Aeronca KCAAeronca 50CAeronca 50TCAeronca S50CLuscombe 8Piper J-3Piper J-4Porterfield CP50Porterfield CP55Taylorcraft BCTaylorcraft BCSA65Aeronca L-3Aeronca S65CAeronca S65CAAeronca 65FAeronca 65CAAeronca ChampionAirdrome Fokker D-VIIIBearhawk LSAChristavia Mk ICirca Reproductions NieuportCoupé-Aviation JC-01Ercoupe 415CE & P SpecialFalconar F11 SportyFisher CelebrityFisher Dakota HawkHelmy AerogyptHenderson Little BearInterstate SIA CadetJameson RJJ-1 Gipsy HawkJodel D.112Luscombe 8ALuscombe 10Piper J-3Piper J-4APorterfield CP65Rearwin Skyranger 165Smith MiniplaneStolp SA-900 V-StarTaylorcraft BCSTaylorcraft BCS12Taylorcraft 65Tayorcraft BCTaylorcraft BC1265Taylorcraft BCTTaylorcraft L-2Taylorcraft TandemTurner T-40Warner Revolution IWolf W-11 Boredom FighterA75Bearhawk LSACulver LCAJodel D.121Luscombe 8CLuscombe 8DPiper J-4EPiper J-5Porterfield 75CRearwin Skyranger 175Stinson HW75A80Harris Geodetic LW 108Shirlen Big CootieVought V-173Data from Continental Aircraft Engine Operator's Manual
Type: 4-cylinder air-cooled horizontally opposed aircraft piston engineBore: 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)Valvetrain: One intake and one exhaust valve per cylinder, pushrod-actuated.Fuel system: Updraft carburetorFuel type: 80/87 octane avgasOil system: Wet sumpCooling system: Air-cooledPower output: 65 hp (48 kW) at 2,300 rpmSpecific power: 0.38 hp/in³ (17.1 kW/L)Compression ratio: 6.3:1Fuel consumption: 4.4 US gal/hrOil consumption: maximum desirable 0.37 US quarts/hrPower-to-weight ratio: 0.38 hp/lb (0.62 kW/kg)
