Corrrrect

So you need to, Measure your combustion chamber and note the volume... we'll call that "Comb V"

Piston dish we'll call "Pd"

Compressed Gasket Volume "CGV

And the volume for the Crown to the Deck "CD"

and we'll do it the dodgy fitter (just stirring ) way and skip the ring land to crown, because you would physically need to measure the piston crown diameter and the bore size, then the distance from the top edge of the ring land to the crown then work out the volume....

So to help you out, the gasket volumes are ..

3.8cc for a copper gasket

4cc for a BK450

4cc for an Aluminium compsite gasket...

So, once you measure the volume of the combustion chamber, and piston dish... we'll go -->

Comb V + Pd+ CGV+ CD = Combustion space


(note that size)

Then add that to 345 (swept vol of 1 cylinder) and devide the answer by the combustion space

That will give you your compression ratio


Clear as mud?



[EDIT] Woop, doc beat me too it [/EDIT]