>>>*Sure, I think I can. The obvious benefit is the opening is larger, simple as that.

This means more fuel/air mix can pass at a given lift. But the situation is vastly more complicated than that, otherwise we would just install the biggest valve we could get in there and be done with it.

The increased head size means an increased pattern across the cylinder, so distribution is improved. Then we know that the first .100" of valve lift offers the best atomization due to high pressure under the intake (Think of that spurt of water you get when you take your finger off the end of a water hose)

So size helps in many ways. Add in that bore size, stroke, and expected engine speed to port velocity has to be taken into account, and there are limits to what is the best size.

So just like a 2.02" intake valve adds perhaps 5-6% to a typical smallblock Chev V-8 over the stock 1.94", the same thing happens with a little Toyota 4 cylinder, or even the V-6.

The effect is less noticeable in the lower RPM ranges, and increases as engine speed increases....*EB