Though the Blacktop head features a far more open combustion chamber (see “Head combustion- chambers”) it continue to has a greater static compression ratio (see “compression ratio”), this is purely due to piston style and design. The Silvertop piston encompasses a very small dome with two deeply angled exhaust flycuts, https://kameronopnnl.tokka-blog.com/31575567/5-easy-facts-about-toyota-4a-ge-described