Everyone knows the WW2 PT boat was a rocketship, and that it was powered with big, beefy engines. What many are unclear on is exactly what they were, and where they came from. In this video we go through the development history of the Packard M-2500 series of engines, and common misconceptions as to what they were.
No monkeys were harmed in the making of this video.

Chapters
0:00 Start
1:53 Liberty L12 engine
4:33 Packard 1A-2500
8:00 Packard 1M-2500 marine engine

Sincere thanks to Randy 'Motor Mac' Smith for the video clip of a 4M engine starting up.