This Buell new-engine thread just won't die...
Look guys, you just can't take a different engine and jam it into a motorcycle, as you might with an automobile. Bikes and their engines are intimately related. The character of a bike is dependant on the engine. Swapping motors leads to other changes in the bike structure that inevitably result in a different motorcycle.
This would be especially important in any redesign of the Buell. One of the key elements that separates the current Buell design from other V-twin sportbikes is the frame geometry and extremely short wheelbase, which gives the bike that Atomic Unicycle feel that I love so much. Ducatis have wheelbases like semis, and as a result they feel quite different than Buells. I ain't saying that's bad... but it is not the Buell "feel".
Designing this imaginary new Buell motor in a way that would allow it to fit in the space the Sportster motor occupies in existing frame might be a real challenge, and might not be possible. Altering the frame will change the character of the whole bike.
You want really big power from this new motor, don't you? Well then you will require water cooling. Which of course means you must find a place for a water pump, hoses, and that damn radiator. There is no place on the current Buell to locate these things. In order to accomodate them the frame must be altered and the wheelbase lengthened. There we go again... it no longer feels like a Buell. (Note: I don't want to see another damn reference to the V-Rod motor in this thread--- while it is a wonderful power plant indeed, it is absolutely WRONG in a Buell--- it's way too big and heavy and expensive).
And what configuration will the new Buell motor be? 90-deg.? 60 deg.? Like an Italian motor? Perhaps... but call me the old fossil that I am--- I really don't want to give up the heartbeat of that 45-deg. V-twin. I love that pulse, and those other engines just don't have it, no matter what kind of open pipe you might put on them.
We would all like more power, but aside from bumping up the displacement of the current engine another 100cc or so, I don't see how to get that power without destroying the character of the bike, which I am not willing to do. Track days aside, the current engine is perfect for real-world street/commute/canyon riding. I rarely feel as though I am being "left-behind", and if I do, its not because of any lack of ponies, its because I have two left feet.
Do not sell H-D short on engineering talent and marketing smarts. If Buell TRULY needs a new engine, mama will buy. But I really don't believe it is required. But perhaps I'm way off base here... anyway, didn't mean to rant.