I live in an area that old WW2 planes fly over often. Nothing like the sound of a radial engine! I try to imagine the sky with hundreds of planes when they flew in anger 80 years ago, must of been a sight to behold. Lovely flying history.
For whatever reason, the Miami Space Transit Planetarium used to have on display a cut-in-half Pratt & Whitney R2800 Double Wasp radial engine. The thing was fascinating, you could stare at it for half an hour just trying to trace how all the parts moved.