O/S intake valves...

Here a link from. Org that discusses the half moon dot in the CC
http://www.slantsix.org/articles/combustion-chamber/sl6-combustion-chamber.htm

Thank you srixon4405, If I am reading it right (reading comprehension) is not my strong point, My head with the half moon looking thing (pump) burns better.
Or did I misunderstand what I was reading, and I read it twice, ok three times ? :shaking2: