Jason had also cced the heads by using a graduated burette to find out exactly how many ccs of fluid it took to completely fill the combustion chamber, with a plastic plate of the proper diameter for the bore size set into the head. Our heads measured an even 64cc on each chamber. Jason did some quick calculations, and found that, with our 0.085 deck height and 64cc combustion chambers without any barrel spacers between the case and the cylinder, e would have a compression ratio of 7.05-to-1. Of course, you need to have a spark plug screwed into the combustion chamber, to avoid a liquid mess at the bottom of your work table.