Compression ratios - how to work out???

[matt dunn]

Ok you math genius's..

Work this out...

4AGE 20V compression ratio.

Low compression dished pistons and modified head

CC is 1587
Piston combustion volume is 15cc
Head combustion volume is 35cc

Now head gasket thickness is 1.25mm
Need to convert this to a volume amount to work out volume
Bore size is 81mm

So somehow using 1.25, 81 and pie?? you can work it out.
Been a few years since i was at school.

[fivebob]

6.44cc for the head gasket volume, 8.03:1 CR

Formula for gasket volume is (bore/20)^2 x pi x thickness/10.

And I'm willing to bet it's been a lot longer since I went to school