[Canuck]

Found This:

Propulsion
3 5M-2500 Packard-Marine V12 Engines.

These engines are 4 stroke, water cooled, 60 degree, V- type with a 6-3/8" bore and 6-1/2" stroke, for a total of 2490 cubic inches of displacement. Each engine has 48 valves, 2 inlet/2 outlet per cylinder. They have a compression ratio of 6.4:1, and are fitted with a gear-driven centrifugal supercharger and intercooler. The engines are installed with a Holley 1685F aircraft-type carburetor, and use aircraft- type dual magneto sparks, with 2 spark plugs per cylinder. The engines develop 1500 Hp at 2500 rpm.Max revolutions is 3000 rpm. Engine weight is 3100 pounds. These engines were designed to burn 100 octane aviation gasoline to achieve nominal power output.

I visited the WWII museum in New Orleans in 2001 and learned of the History of Higgins Boat Works ,the company that built a lot of small craft for the Navy including the landing barges.

Paul