Originally Posted by
Scoff
well, we know we have 499.5cc of swept volume per cyl. IE, 1998cc in total.
standard CR is 11:1 so from that we can calc how much volume is in the standard combuistion chamber (including gasket, valve depressions in piston, etc etc):
swept vol
------------
cr-1
499.5
-------
11-1
= 49.95cc
If we want to get to 9.5:1 we need to calculate the new combustion chamber volume:
499.5
-------
9.5-1
= 58.76cc
That tells us we need to add 8.81cc's to each chamber (58.76 - 49.95).
using pi x r2 we can work out that 1mm of piston height is worth 5.37cc's of volume, so you need to remove (8.81/5.37) = 1.64mm