The cranking PSI on my slant 6 is over 175 PSI and I run on pump premium with zero spark knock. It runs on 87 with no spark knock, but it runs a lot better on premium. His advice worked very well for me.
And meanwhile my 340, which is at 9.8:1 and cranks at 180-185 psi will detonate on 91 octane at sea level in the summer if I go past 34° mechanical timing.
And that’s my point, I’m not saying his advice doesn’t work, I’m just saying it won’t work for everyone or every build. I can’t get 94 octane at a normal gas station, and I drive entirely too much to run fuel I have to buy at a track.
Saying every build should be tuned for a 160° coolant temperature is naïve.
