Why do Mopar Engines Have a Different Sound From Chevys and Fords??
Harley went so far as to patent the "Harley sound". They even went after one of the Japanese manufacturers (I forget which one), when they changed their valve layout after doing some homework. The result was an engine that sounded an awful lot like a Harley engine, and a lot less like the Japanese metric cruiser that it was.
Anyway, the sound will be tied to the valve positioning, exhaust port design
It was Honda with the a.c.e. American classic edition. What they changed was the crank timing. The sound is created by the 45 degree V twin with a 360 degree crank or common crank pin.
I definitely can tell when a 4.6L Ford mod motor is coming. The new Corvette has a destinct sound too but more from the exhaust arrangement. V8's with a 180 degree cranks or headers have a unique sound too.