Although the Blacktop head contains a a lot more open up combustion chamber (see “Head combustion- chambers”) it continue to has a better static compression ratio (see “compression ratio”), this is only because of the piston layout. The Silvertop piston includes a incredibly little dome with two deeply angled exhaust https://4age-engine-for-sale46458.blogdomago.com/30496263/what-does-blacktop-20v-4age-mean