In many respects the “Cyclone 18” is a two-row development of the “Cyclone 9”. Of course it has 18 cylinders and was usually supercharged.

It was first run in 1937 and remained in production into the 1950s. Power was typically 2,500 hp, and famous applications included the Boeing B-29 ”Super Fortress”, Fairchild C-119 “Packet”, Lockheed C-121 “Constellation”, and Douglas A-1 “Skyraider”.

Our example is a time-expired engine from a Martin “Mars” flying boat, donated by Forest Industries Flying Tankers.