Seven magnetos, 56 spark plugs, and 28 cylinders.

It's a Pratt and Whitney 4360 Wasp radial engine introduced in 1944, and freshly restored.

Each row of pistons was slightly offset from the previous, forming a semi-helical arrangement to facilitate efficient airflow cooling of the successive rows of cylinders, with the spiraled cylinder setup inspiring the engine's "corncob" nickname. A mechanical supercharger geared at 6.374:1 ratio to engine speed provided forced induction, while the propeller was geared at 0.375:1 so that the tips did not reach inefficient supersonic speeds. Initially, it developed 3,000 horsepower, later models gave 3,500 horsepower.

Turn up the volume and run the wife, the cat and anyone else who doesn't like the roar of raw power out of the room.


Pratt & Whitney R-4360-20 first start from Dave O on Vimeo.

Some more stories on corncobs and Corsairs.