12 Second N/A Slant 6?
OK, this 89mm KB 2.2L turbo piston has -18cc voluume.
If a head milled .113" & has 44cc chambers W/about -.087" deck, then a positive piston/block deck of .067" that would leave .055" quench. (.035" compressed head gasket)
Opening up the quench area to 89mm will add 1cc volume.
So 45cc - .035" deck (difference between .087 & .055) would reduce the voluume by about 6cc. 39 + 18 = 58cc
240 cu in /6 = 40 cu in per cylinder = 656cc per cylinder + 58cc = 714cc total cylinder/combustion chamber voluume.
714cc/58cc = 12.3:1 CR.
I would need to increase the combustion chamber voluume by 11cc (W/O increasing quench distance) to get down to 10.5:1. That would be hard to accomplish.
Would .055" quench allow me to run 93 octane W/a cam that would not build chamber pressure @ lower RPM coupled W/a less aggressive spark timing curve?