[PFM]

Chris,

The compression ratio a motor can live with is not directly related to the number of plugs per cylinder. Bob was talking about a motor with 17 to 1 compression ratio, that motor had a single plug per cylinder. For the Porsche Hemi head the second plug was to help light the " other half" of the cylinder. Look at you piston and how it fits the head, a single plug near the intake leaves the exhaust side to fend for it's self. A lower compression motor has a more open chamber and does not benefit as much from a second spark source. If you search peanut chamber you will find that Henry welded up the heads to increase compression while using a single plug.

If octane for the higher compression is an issue consider setting your motor up to run on E85 if available in your area.