A50
50 hp (37 kW), Compression ratio 5.4:1, max rpm 1,900, fuel consumption at cruise 3.8 US gph
A50-1
A50-2
A50-3
A50-4
A50-5
A50-6
A50-7
A65
65 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.

A65-1
A65-2
A65-3
A65-4
A65-5
A65-6
A65-7
A65-8
A65-8F
A65-9:
A65-12
A75
75 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.

A75-1
A75-2
A75-3
A75-4
A75-5
A75-6
A75-14
A80
80 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.

A80-1
A80-2
A80-3
A80-4
A80-5
A80-6
A80-8
O-170
Military designation for the A50, A65, A75, A80 family of engines.

O-170-1
O-170-3
O-170-5
O-170-7
A50
50 hp (37 kW), Compression ratio 5.4:1, max rpm 1,900, fuel consumption at cruise 3.8 US gph
A50-1
A50-2
A50-3
A50-4
A50-5
A50-6
A50-7
A65
65 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.
A65-1
A65-2
A65-3
A65-4
A65-5
A65-6
A65-7
A65-8
A65-8F
A65-9:
A65-12
A75
75 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.
A75-1
A75-2
A75-3
A75-4
A75-5
A75-6
A75-14
A80
80 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.
A80-1
A80-2
A80-3
A80-4
A80-5
A80-6
A80-8
O-170
Military designation for the A50, A65, A75, A80 family of engines.
O-170-1
O-170-3
O-170-5
O-170-7
Continental O-170