Although the Blacktop head includes a far more open up combustion chamber (see “Head combustion- chambers”) it continue to has the next static compression ratio (see “compression ratio”), this is purely because of the piston structure. The Silvertop piston includes a very smaller dome with two deeply angled exhaust flycuts, https://b16engineandtransmissionf61466.theisblog.com/31538432/indicators-on-4age-20v-you-should-know