Although the Blacktop head features a a lot more open up combustion chamber (see “Head combustion- chambers”) it even now has a better static compression ratio (see “compression ratio”), this is only due to piston design. The Silvertop piston incorporates a very compact dome with two deeply angled exhaust flycuts, https://andresgwmxi.blogsuperapp.com/31863927/the-basic-principles-of-4age-20v-for-sale