While the Blacktop head includes a extra open combustion chamber (see “Head combustion- chambers”) it continue to has a higher static compression ratio (see “compression ratio”), this is only due to the piston style and design. The Silvertop piston features a really smaller dome with two deeply angled exhaust flycuts, https://bookmarkmargin.com/story18511137/5-simple-techniques-for-4age-blacktop-engine-for-sale