While the Blacktop head encompasses a far more open combustion chamber (see “Head combustion- chambers”) it continue to has a better static compression ratio (see “compression ratio”), this is only due to piston style and design. The Silvertop piston encompasses a very tiny dome with two deeply angled exhaust flycuts, https://ariabookmarks.com/story4171812/indicators-on-4age-20v-turbo-engine-for-sale-you-should-know