It's a 700c.c. supermono, not a punny 450
.... been dynoed at 75 rwhp
Sorry if i dont agree with hondaman ideas, it will not be the first time. what i am trying to tell you here is essentially DONT to do the angled cut in the head, i.e. NOT to do the "potential quench band cut" in the drawing. with flat pistons youll get wonderful squish if you bring the crown close enough to the head surface, so leave the head alone, get the right squish by milling the block.
the opening of the chamfers is a bit old school approach, current approach to squish is to maximize the flat areas of piston and head. check out latest heads of air cooled 2 valve Ducs.
the same idea is applied in all 4 valve heads today, nobody "opens the chambers" in them (though you could), instead, they leave large flat areas to do exactly the same as i am suggesting here.
The only evidence i have to the effectiveness of my idea (well, not entirely mine
) is the burn pattern i see that leave the piston crown clean in the squish zones due to the high gas velocity and the super low ign. advance i run to get max power, in the 25-28 degrees area.