I haven't been able to pin down the nominal CC of an 848 head because of different static CR listed for different years, etc. With low ratio, even a few 1/10ths make a big difference.
Using nominal engine size: chamber volume in CC of 1 cylinder =
((displacement ÷ 6) ÷ (CR - 1)) × 16.387
Example:
261 ÷ 6 = 43.5"
If the static ratio were 8.25, divide by 7.25 = 6", multiple by 16.387 = 98.3cc
To get 9.0:1 in a 261 you need 89.1, etc.
