In the past century, the internal combustion engine has been one of the most studied and developed devices in the civilized world. Historically one of the most studied elements is the intake system. Recent1y there have been many major advances, some of which are variable valve timing, methods of lift control, and 4 (or more) valve per cylinder designs. There is still a large amount of development to go, with which gasoline powered cars will not only be the cheapest, most powerful automobile - but also the cleanest.