Originally Posted by
DaveReidUK
Though most "left-handed" piston engine cranks actually rotate in the conventional direction, but have a gearbox that produces prop rotation in the opposite sense.
I think that you're mistaken about this. The only twin engine airplanes I know of which have counter rotating props have direct drive engines.
Common airplanes with counter-rotating props include: The Beech Duchess, Piper Seminole, Seneca, certain models of the Navajo, including the Chieftain, and the Cessna Crusader. all with direct drive engines ie: Prop is bolted directly onto the crankshaft.
I think you'd be pretty hard pressed to name a common GA aircraft with geared engines and counter rotating props.