Re: Excellent point and Good discussion
There's also the fact that Harleys have small bores for the displacement and two valves per cylinder. Air velocity in the intake ports has to get mighty high to get any real amount of air in at high rpm. More valve area for a given cylinder displacement allows less lift and duration to feed the same amount of air.
Of course, the better metals and design help pistons and rods handle more acceleration than they used to take. Also, you have to assume that even a very aggressive rider isn't going to constantly stay at redline.
Personally, I don't have a clue what kind of mileage can be had from a well-maintained bike engine with any rpm range. Results seem to vary so much as to be meaningless.
There's also the fact that Harleys have small bores for the displacement and two valves per cylinder. Air velocity in the intake ports has to get mighty high to get any real amount of air in at high rpm. More valve area for a given cylinder displacement allows less lift and duration to feed the same amount of air.
Of course, the better metals and design help pistons and rods handle more acceleration than they used to take. Also, you have to assume that even a very aggressive rider isn't going to constantly stay at redline.
Personally, I don't have a clue what kind of mileage can be had from a well-maintained bike engine with any rpm range. Results seem to vary so much as to be meaningless.