You don't want much do you
How about the new BMW F1 engine? It hits 19,000 rpm. How about that for a four stroke piston engine!
The short answer (all I can give here) is engineering. Parts engineered and built specifically to operate at high RPM.
Here is some generalities
Why? Power. Through in some cool factor. An engine is an air pump. To produce more power it must pump more air. You can do this by increasing efficiency, RPM, or size of the pump. Of course you must engineer the whole package to work together. Packaging, target market and price, usage, etc all figure into how much do you want.
Higher RPM = lighter, stronger, more careful design and assembly, more exotic materials = Bigger bucks.
Lambo = $200,000, Mustang = $20,000. So you can afford to 'play' a lot more with the engineering in a Lambo than you can in a Mustang.
So why do most of our motors not run 8000 RPMs all day? For the most part we are all using engines that where originally designed for mass produced cars and trucks at a relatively low cost point. Why do you think you hear 'there is no substitute for cubic inches' all the time? Well actually there is. It is MONEY!