Re: REAL 80+ CC Happy Times!
Assuming no changes made to porting(which are critical in regards to piston positioning) the only way to increase it as you're alluding to is to increase the bore. In a car, one would bore out the cylinders and slap in wider pistons. From what I understand, these engines have just enough metal for the existing pistons. If one was knowledeable about custom manufacturing their own pistons to match their own crankcases...well, now we're talking about scratchbuilding.