M3 Compression Ratio. Velocity pressure to static?

[Neil Deshpande <deshpand@xxxxxxxxxxxxxxxxxxxxxxxxx>]

If the highest measured pressure at a cylinder is 13.75 bar, and the
intake pressure is atmospheric or 1 bar (actually, I remember that about
1.012 bar is 760 mm Mercury or 1 atm), should not the compression ratio be
about 13.75:1? 

I know there is some other factor since the compression is most certainly
not 13.75. 

Perhaps the flow rate of the intake air, etc., leads to some 'charging'
effect since some velocity pressure is converted to static pressure
(Bernoulli Principle) before the valves are closed so the initial charge
is not at atmospheric.  This would explain the advantages of the ram
air/scoop thing that people keep mentioning. 

Anyone care to detail what it is. 

Neil Deshpande
86 325
88 325 is
89 325 iC

------------------------------