small block heads questions

These engines are not as bad as some when it comes to dome design. Valve angle has alot to do with it. Take a SBC with a 23* valve angle(pictured) as a example, although some early 340 race pistons approched this level. This is what happens when you get up into the 12,13,14 to 1 range and it can be intrusive to flame travel and a full burn for max power. Most engines like this have to advance the spark timing to get a full burn before the dome walls it off from the far side. Most builders i was associated with back in the day always prefered a flat top, and even a slight dish as the most efficient design.