Bill, in regards to sparkplug placement, you are wrong. The SOHC placement is superior and allows for a more efficient combustion. There is a significant power loss with a centralized plug (especially with domed pistons) and the charge burn can be hindered upon combustion.

With the right valve springs, valvefloat will hardly be an issue. I would be more concerned with the stroke and piston speeds.

BTW, I didn't bring up the F1 car example, matraca112 did.