Originally Posted by blue05
There is not a squish area on our heads. They are basically hemi heads. Plus we also have dished pistons. If we had flat top pistons and a matching flat spot opposite the plug those grooves might do something. All those pics were of sb chevys and fords.
Subarus have a pent roof combustion chamber with a quench pad above the intake valves and one below the exhaust valves. When you put EJ205 heads on an EJ257 block, those quench areas become much bigger and you get quench area around the whole perimeter of the combustion chamber because of the smaller chamber size of the EJ205 head. This interests me because I am in the process of building a hybrid.