Bingo if my CR is too high it would explain the detonation possibly but also I don't know what cam is in there. Ultimately I want to try and estimate the CR but I also don't know the swept volume etc so I don't think I can do that.
I feel for you, having been through engines where I didnt know.
But unless you're going to pull the heads, just knowing its relatively high is good info.
The cam you could get a sense of with a degree wheel and dial indicator.
As far as the pinging, its not the CR's fault per se. It's that the 'typical' hot rodder thinking of more and quicker timing adv is wrong for those conditions.
Conditions are favorable for a good hot combustion right off idle so long lead isn't needed. You'll have to experiment and make decisions based on performance. If you change fuel, you may have to adjust again.
