>Yeah, but.....
>
>The issue here is that the compression numbers actually seen are HIGHER than
>those predicted. At cranking speeds, all of the cam timing factors work to
>LOWER the pressure from that theoretically predicted. Now what?
>
>-Karl
yes, but two things work to raise pressure above predicted in compression
tests, first is the fact that compressing a fixed volume of gas (doing work
on it) in a closed system that doesn't allow temperature equilibration
increases total energy and, therefore, temperature, and, therefore,
pressure beyond what would be expected at constant temperature (i know i'm
dangerously unbalanced, but i loved thermodynamics as a chemistry
undergrad!)
second, *carbon*- carbon on your heads/pistons takes up space, effectively
reduces size of combustion chamber and, therefore, increases compression
ratio, causing knocking even if timing is perfect
joe
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