I don't really like the sound of a six. I think even a Porshe sounds like a boat. There is something completely magical about the sound of a highly tuned V-8 though. Can you imagine a Valkerie-type power cruiser with a 2000cc, 200hp V-8? I'm not even a cruiser guy at all (2003 Aprilia Falco), but I'd buy one of those just to put loud pipes on it and listen to myself cruise around.
Look up the Morbedelli V8. Developed in the early '90's, it never made it into production. Only three were made. It was a twin cam, 850cc motor and it looked like a scaled down Cosworth V8 F1 engine. It fit so nicely in the frame. Mounted long ways, it had shaft drive with a paralever rear suspension. Estimated retail price had it gone into production - $45,000.
"One afternoon I was cruising one of my favorite twisty two-lane backroads at about 60 mph when suddenly I was buzzed by an F15 Eagle about 50 feet off the deck -- or at least that's what it sounded like."
I had two A-10s come over at treetop level when I was on a twisty in New Hampshire. PHWAORRR! I crapped 'em.
Same thing happened to me on a Montana road when I was going flat out my Honda Interceptor at the time. A was tucked in when I hear this roar building. I though it was my engine ready to blow or some potential catastrophe, and then... VVRRRROOOOOOOM... a 12 cylinder Lamborghini Countach with Alberta plates flew past me like I was standing still. What a rush. Boy did I feel inadequate suddenly with my little V4.