Compression Ratio Calculation

[Bill Loubiere <loubiere@earthlink.net>]

Is there a calculation which you can use the compression test data to
calculate the compression ratio on your car?

I suspect that many things has happened to my MGTD before I purchased it
this year.  I was wondering how to back calculate the compression ratio
based on the compression test readings.  I don't plan to change anything.  I
just wanted to know what it might be.

Thanks
Bill