If you want performance then you know you have to get as much air into the cylinder as possible! The bigger the valves the more this is possible! The stock Sprite motor has only 1.3" intake valves, the stock Cooper "S" has 1.41" intake valves. Our Special Big Intake valve is 1.464"! This is a competition quality valve that will also work long and hard on any street car! Our race valves are produced in EN214N steel, stellite tipped and use the later narrow collet groove and current valve head shapes. Sold individually.