So, what is the magic number to run pump gas? Obviously, if so much credence is given to this one parameter, then someone has to have a number they are looking for. Otherwise, it is just a guessing game.

The fact is, there are engines that will rattle with less than 8:1, and others won't rattle at 10:1 DCR. How do you know what is correct? How can a tool be so valuable if the target is constantly moving, and the real world numbers don't correlate to the formula result? I'm not saying the DCR doesn't have some value if used properly, but when ALL parameters aren't considered, like is often the case, the DCR is almost meaningless.

I think Brad is showing his frustration that he built his engine to run on pump gas, using a DCR calculation, and it didn't work out that way. There are lots of guys out there blowing their stuff up from detonation, when they thought they were safe. And yet, guys are still recommending engines be built using the DCR. That being said, if that's what works for you, go for it.