60 cc's closed chamber so a squish area is possible but I can find no piston that will give an acceptable (9 to 1) CR and maintain a squish area.
Flat top pistons, which BTW I also haven't been albe to find will produce around 12 to 1 -- ah if only 110 octane gas were available. It looks like I need a 30cc dish. Actually a D dish if squish area is to be maintained.
Does anyone know? Is 30cc's an impossibly large dish? I've seen 18. Not for this engine but I at least know an 18cc D dish is possible.
With those heads and the right pistons this 400M would be a screamer.
I also plan a fuel injection. The thermactor will have to be changed to blow into the cats instead of the intake manifold as that would interfere with a O2 sensor but I see no problems there -- except possibly legal. Just because it's better, greener, doesn't mean it's legal but I'm hoping if we get inspections here they will be car guys enough to see reason but who knows. A closed loop fuel injection, three way cats and a combustion chamber with a proper squish area would be greener than anything produced by Detroit until at least 1990 and mine is a '77.
If anyone knows anywhere online piston, piston information (I don't even know the stock specs), for the 400M may be found please help.