Without tearing down the engine to measure, is there a way to determine the compression ratio that a car has?
I would like to know what I am running but don't have an idea on how to check it.
The link in the above post if all the information is know will give you the compression ratio. But there are also other factors, such as rod length, cam which change the valve stroke compression on closing.
The simple way to understand compression ratio is if you ...
Send a piston to the bottom (valves open) and you could pour 10 gallons of water through the sparkplug hole.
Than sent the piston TDC (valve closed) and you could now only pour in 1 gallon, thats a 10 to 1 compression. Compression is based on volume... piston size + valve CC, bore, stroke etc.