The engines are all carburetor-equipped, feature dual magneto ignition and have a displacement of 233 cubic inches (3.82 L). The first O-235 model was certified on 11 February 1942.
The O-235 was developed into the lighter-weight Lycoming IO-233 engine for light sport aircraft.
O-235-C1Power 115 hp (86 kW) at 2800 rpm, dry weight 246 lb (112 kg) Provision for dual pump drives, tractor and pusher installation.
O-235-C1APower 100 hp (75 kW) at 2450 rpm, dry weight 236 lb (107 kg) Similar to O-235-C1 except ignition timing, lower rpm and power. Optional 2 position or automatic propeller governor drive.
O-235-C1BPower 115 hp (86 kW) at 2800 rpm, dry weight 245 lb (111 kg) Similar to O-235-C1 except with retarded breaker magnetos.
O-235-C1CPower 108 hp (81 kW) at 2600 rpm, dry weight 243 lb (110 kg) Similar to O-235-C1 except with Slick magnetos.
O-235-C2APower 115 hp (86 kW) at 2800 rpm, dry weight 246 lb (112 kg) Similar to O-235-C1 except with a type 1 propeller flange.
O-235-C2BPower 115 hp (86 kW) at 2800 rpm, dry weight 247 lb (112 kg) Similar to O-235-C2A but with two S-1200 series magnetos.
O-235-C2CPower 108 hp (81 kW) at 2600 rpm, alternate rated maximum continuous power rating of 100 hp at 2400 rpm, dry weight 244 lb (111 kg) Similar to O-235-C2B except with Slick magnetos and shielded ignition harness.
O-235-E1Power 115 hp (86 kW) at 2800 rpm, dry weight 250 lb (113 kg) Similar to O-235-C1 except crankcase and crankshaft supply pressurized oil to a constant speed propeller. Accessory case changed to accommodate a standard propeller governor drive.
O-235-E1BPower 115 hp (86 kW) at 2800 rpm, dry weight 249 lb (113 kg) Similar to O-235-E1 except for S4LN-200 series retarded breaker magnetos.
O-235-E2APower 115 hp (86 kW) at 2800 rpm, dry weight 250 lb (113 kg) Similar to O-235-E1 except Type 1 propeller flange.
O-235-E2BPower 115 hp (86 kW) at 2800 rpm, dry weight 251 lb (114 kg) Similar to O-235-E2A except incorporates S-1200 series magnetos.
O-235-F1Power 125 hp (93 kW) at 2800 rpm, dry weight 250 lb (113 kg) Similar to O-235-C1 except compression ratio, fuel grade and rating.
O-235-F1BPower 125 hp (93 kW) at 2800 rpm, dry weight 249 lb (113 kg) Similar to O-235-F1 except retarded breaker magnetos.
O-235-F2APower 125 hp (93 kW) at 2800 rpm, dry weight 250 lb (113 kg) Similar to O-235-F1 except a Type 1 propeller flange.
O-235-F2BPower 125 hp (93 kW) at 2800 rpm, dry weight 251 lb (114 kg) Similar to O-235-F2A but with S-1200 series magnetos.
O-235-G1Power 125 hp (93 kW) at 2800 rpm, dry weight 253 lb (115 kg) Similar to O-235-F1 except provisions for using constant speed propeller.
O-235-G1BPower 125 hp (93 kW) at 2800 rpm, dry weight 252 lb (114 kg) Similar to O-235-G1 except has retarded breaker magnetos.
O-235-G2APower 125 hp (93 kW) at 2800 rpm, dry weight 253 lb (115 kg) Similar to O-235-G1 except a Type 1 propeller flange.
O-235-G2BPower 125 hp (93 kW) at 2800 rpm, dry weight 254 lb (115 kg) Similar to O-235-G2A except S-1200 series magnetos.
O-235-H2CPower 108 hp (81 kW) at 2600 rpm, alternate rated maximum continuous power rating of 100 hp at 2400 rpm, dry weight 243 lb (110 kg) Similar to O-235-C2C except Type 1 dynafocal mounting.
O-235-J2APower 125 hp (93 kW) at 2800 rpm, dry weight 252 lb (114 kg) Similar to O-235-J2B except magnetos.
O-235-J2BPower 125 hp (93 kW) at 2800 rpm, dry weight 253 lb (115 kg) Similar to O-235-F2B except Type 1 dynafocal mounting.
O-235-K2APower 118 hp (88 kW) at 2800 rpm, dry weight 252 lb (114 kg) Similar to O-235-F2A except ignition timing, lower power and reduced compression ratio.
O-235-K2BPower 118 hp (88 kW) at 2800 rpm, dry weight 253 lb (115 kg) Similar to O-235-F2B except ignition timing, lower power and reduced compression ratio.
O-235-K2CPower 115 hp (86 kW) at 2700 rpm, dry weight 248 lb (112 kg) Similar to O-235-K2A except Slick magnetos.
O-235-L2APower 118 hp (88 kW) at 2800 rpm, alternate ratings of 115 hp (86 kW) at 2700 rpm, 112 hp (84 kW) at 2600 rpm, 110 hp (82 kW) at 2550 rpm and 105 hp (78 kW) at 2400 rpm, dry weight 252 lb (114 kg) Similar to O-235-J2A except ignition timing, lower power and reduced compression ratio.
O-235-L2CPower 115 hp (86 kW) at 2700 rpm, alternate ratings of 115 hp (86 kW) at 2700 rpm, 112 hp (84 kW) at 2600 rpm, 110 hp (82 kW) at 2550 rpm and 105 hp (78 kW) at 2400 rpm, dry weight 249 lb (113 kg) Similar to O-235-L2A except Slick magnetos and lower maximum continuous rating.
O-235-M1Power 118 hp (88 kW) at 2800 rpm, alternate ratings of 115 hp (86 kW) at 2700 rpm, 112 hp (84 kW) at 2600 rpm, 110 hp (82 kW) at 2550 rpm and 105 hp (78 kW) at 2400 rpm, dry weight 255 lb (116 kg) Similar to -L2A except provision for controllable propeller and has AS-127 Type 2 propeller flange.
O-235-M2CPower 118 hp (88 kW) at 2800 rpm, alternate ratings of 115 hp (86 kW) at 2700 rpm, 112 hp (84 kW) at 2600 rpm, 110 hp (82 kW) at 2550 rpm and 105 hp (78 kW) at 2400 rpm, dry weight 252 lb (114 kg) Similar to O-235-M1 except Slick 4200 series magnetos and Type 1 propeller flange.
O-235-M3CPower 118 hp (88 kW) at 2800 rpm, alternate ratings of 115 hp (86 kW) at 2700 rpm, 112 hp (84 kW) at 2600 rpm, 110 hp (82 kW) at 2550 rpm and 105 hp (78 kW) at 2400 rpm, dry weight 252 lb (114 kg) Similar to O-235-M1 except Slick 4200 series magnetos.
O-235-N2APower 116 hp (87 kW) at 2800 rpm, alternate ratings of 113 hp (84 kW) at 2700 rpm, 110 hp (82 kW) at 2600 rpm, 108 hp (81 kW) at 2550 rpm and 103 hp (77 kW) at 2400 rpm, dry weight 252 lb (114 kg) Similar to O-235-L2A except reduced compression ratio and reduced power ratings.
O-235-N2CPower 116 hp (87 kW) at 2800 rpm, alternate ratings of 113 hp (84 kW) at 2700 rpm, 110 hp (82 kW) at 2600 rpm, 108 hp (81 kW) at 2550 rpm and 103 hp (77 kW) at 2400 rpm, dry weight 249 lb (113 kg) Similar to O-235-L2C except reduced compression ratio and reduced power ratings.
O-235-P1Power 116 hp (87 kW) at 2800 rpm, alternate ratings of 113 hp (84 kW) at 2700 rpm, 110 hp (82 kW) at 2600 rpm, 108 hp (81 kW) at 2550 rpm and 103 hp (77 kW) at 2400 rpm, dry weight 255 lb (116 kg) Similar to O-235-M1 except reduced compression ratio and reduced power ratings.
O-235-P2APower 116 hp (87 kW) at 2800 rpm, alternate ratings of 113 hp (84 kW) at 2700 rpm, 110 hp (82 kW) at 2600 rpm, 108 hp (81 kW) at 2550 rpm and 103 hp (77 kW) at 2400 rpm, dry weight 255 lb (116 kg) Similar to O-235-P1 except a Type 1 propeller flange.
O-235-P2CPower 116 hp (87 kW) at 2800 rpm, alternate ratings of 113 hp (84 kW) at 2700 rpm, 110 hp (82 kW) at 2600 rpm, 108 hp (81 kW) at 2550 rpm and 103 hp (77 kW) at 2400 rpm, dry weight 252 lb (114 kg) Similar to O-235-M2 except reduced compression ratio and reduced power ratings.
O-235-P3CPower 116 hp (87 kW) at 2800 rpm, alternate ratings of 113 hp (84 kW) at 2700 rpm, 110 hp (82 kW) at 2600 rpm, 108 hp (81 kW) at 2550 rpm and 103 hp (77 kW) at 2400 rpm, dry weight 252 lb (114 kg) Similar to O-235-M3C except reduced compression ratio and reduced power ratings.
Data from Operator's Manual, Textron Lycoming Aircraft Engines.
Type: 4-cylinder air-cooled horizontally opposed piston aircraft engineBore: 4.375 inches (111.1 mm)Stroke: 3.875 inches (98.4 mm)Displacement: 233.3 in3 (3.823 L)Dry weight: 240.0 lb (108.9 kg)Valvetrain: Pushrod-actuated valvesFuel system: CarburetorFuel type: 80/87 avgasCooling system: Air-cooledPower output: 100 hp (75 kW)Specific power: 0.57 hp/in³ (26.0 kW/L)Compression ratio: 6.5:1