This classic US nine-cylinder radial dates from 1931.
Its original rating was 575 hp, but it remained in production until the 1950s by which time the power rating had climbed to 1,525hp! Its best known applications over the years were the B-17 “Flying Fortress”, the DC-3/C-47 “Dakota”, the North American T-28B, and Grumman “Tracker”. We have two examples, one of which was restored by Jeff Phillips.
The other is in a power egg from a “Tracker”.