Looking for some information on a safe compression ratio while running 93 Octane fuel?

 

I've seen up to 12.1 with good tuning

 

Mid to high 11s SCR and mid to high 8s DCR with a good tune will be no problem.

 

Camshaft specs & installed ICL make a big difference to the DCR, thus affecting the octane requirement of the engine.

I have 11.49 CR with a 234/242 .600/.615 117+2 cam in my 418. I use 94 octane and have 22* total WOT spark timing. Any more timing causes audible pinging after the 3-4 shift @WOT. Also I have a 160* stat that keeps the coolant at 172*174*F.

Russ Kemp