Originally Posted by
pdfbt40
Pity, if you were planning a CR increase (without changing pistons) you could have started with a 1.8 head. That will give a 11.0:1 on a 2.0 without any other machining.
If you've found 55cc quoted as a head volume, its most likely an American source as that's the combustion chamber volume on their (lower compression) engines IIRC.
Martin
1.8 and 2.0 blacktop heads are the same mate and they are stamped 1.8/2.0 in the casting ,the silvertop 1.8 and 2.0 are different from what i have been told .