In production from 1953-1986, the Continental O-470 family of engines are popular in light civil aircraft such as the Cessna and Beechcraft.
Continental O-470 Engine

Specifications
Type: 6-cylinder, air-cooled, horizontally opposed aircraft piston engine
Bore: 5.0 in
Stroke: 4.0 in
Weight: 391 lb
Type: 6-cylinder, air-cooled, horizontally opposed aircraft piston engine
Bore: 5.0 in
Stroke: 4.0 in
Weight: 391 lb