One More Thing
Not just any nine-cylinder radial
The R-985 was one of the most successful piston engines ever built; about 39,000 were manufactured between 1930 and 1953 to power light aircraft. This variant, a 1942 R-985-AN14B, drove the Avro Anson V trainer and Mcdonnell’s lone Whirlaway helicopter; earlier versions powered icons like the Lockheed Electra and Beech Staggerwing.
Cooling fins (1) around each cylinder increase its surface area, helping to disperse heat. The intake (blue) and exhaust (orange) ports have valves that open and close on top of the cylinder.
The triangular crank balance (2) in the engine’s center rotates like a gyroscope, distributing the engine’s weight evenly during inflight maneuvers.
This display at the Steven F. UdvarHazy Center, nicknamed “the dancing engine,” is rigged with LEDS to illuminate its operation. If you’re lucky, you may see it run.