I have never found a satisfactory correlation between CR and
compression pressure. It's certainly not as easy as dividing
by 14.7!
There are lots of factors that affect the pressure reading, the
most important of which seems to be heating of the compressed load.
Leakdown past the rings, which one hopes is minimal but is
always present, will affect the peak number.
But to give you another data point, my Morris's 1380cc engine, with
computed CR at almost exactly 8.9:1, sees 195 psi on the cylinders.
It has Total Seal second rings (Highly Recommended!) and measures
less than 2% leakdown.
My presumably stock TR4A engine, which should be 9.0:1, tends
to get 185 or less. It also blows smoke past the rings; I haven't
measured the leakdown for some time (because I'm afraid
of what I'll see).
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