Pratt & Whitney R-4360-20 first start on Vimeo, posted with vodpod thanks to motor-head Carlton Palmer, who included these comments:
Hydrocarbon combustion at it’s finest. Perhaps the pinnacle of gasoline fueled piston aircraft engine technology. 28 pistons going up and down with 7 magneto’s and 56 spark plugs. Notice how the smoke begins to drop off as the piston rings bed in (Wear) with the resulting improved oil control, less smoke . Appears to have been be a very good initial test run.