Actually the formula I mentioned was for approximating the compression ratio
from the psi reading of the compression tester. I certainly don't remember
the formula off the top of my head, but I do remember it being within about
half a point when I applied it to The White car, a TR4A I used to autocross.
I had measured that motor, so I knew what the ratio was, so I could tell that
the adibiatic (?) heating formula was close.
A better way to keep an eye on the progress of enine wear is leakdown testing.
Which I should do on the motor in the Killer Spit. The trouble with that is
one needs to make, and record in a safe place (Gee, can you guess what I did
with the original readings from Killer?) the leakdown numbers when the motor
is fairly new, and check at various intervals to see if the rate changes.
mjb.
|