http://auto.howstuffworks.com/camshaft2.htm

Just found this ... this explains everything that you are looking for (you can click on the "Switch to performance cam" button within the image to see what everyone's talking about. Enjoy! (Also click on next page as they had an excerpt on VTEC)

 

Could you explain this a bit more? Even if the exhaust and intake are open longer, the same amount of air will be in the cylinder regardless of how long they are open, when they close.....pressures will equalize. Just because you have more air flowing through the intake / exhaust valves should not mean that there is more air in the cylinder when they close and combustion takes place. The flow of air should not increase the pressure of the air in the sealed chamber. Some un-burned air will most likely escape during the prolonged overlap. I see how it might help by getting the exhaust fumes out faster, but not by bringing air in.

Please clarify this so I know in the future.

John

 

its not really the amount of air but the also the better mixture of air and fuel, hotter gasses have higher velocity which create a suction effect pulling in the fresh charge, also the since the fresh charge is cooler it is denser.

if you want to learn i reccomend a set of books by Carroll Smith , (tune to win, engineer to win, drive to win, prepare to win, and some other which slip my mind right now)

 

Thanks...I will look into it.

John