2. If the Lycoming and Continental paradigm of large displacement
light slow turning engine was so great for aircraft, they would be
great for a lot of other things as well.

Airboats.
Hovercraft.
Tanks (some WWII tanks used a radial aircooled engine, which some
homebuilders converted for their airplanes).
APUs (Lyc O-290-G).
Helicopters.
Cars (Franklin, VW, Corvair, Tucker, and others, though the RPM was
higher, as it is in the same basic aircraft engines that are used in
helicopters).

Dan