Its a tad late to get into a technical essay about squish, but very briefly:
The squish area is the thinest area between piston and cylinder head and is usually engineered to be the full circumference of the piston.
The purpose of this very close area is to force as much of the potent fuel mixture to the center of the clearance volume as possible, so when the burn is initiated we have maximum progression from the kernel of the mixture with a nice even and progressive burn outwards.
Having loose pockets of fuel in the area around the cylinder walls can result in a mixture that can, when the cylinder pressures rise, spontaneously combust, and start to destroy the surrounding metal, much the same as is evident in some of the above pictures.
Often, removing squish will be deemed to have "Fixed" an awkward engine, when in fact, the lowered CR was in fact the alteration that had the effect. This lower compression cylinder with higher squish clearance is actually more prone to det than one left alone and bowled in most cases, due to the aforementioned reasons
The moral?
Get a Pro to BOWL out your pistons, not hacksaw teh fookin tops off
brad,
Stu do you ever finish workin m8 ?
This is pleasure for me pal, i enjoy chattin shit to folks, its better than watching tv etc IMO.