YTNUKLR
I thought I was talking about twin plug motor, not single. Yes that would be to high for a single plug street fuel motor.
However, factory 3.6 twin plug motors run near this compression. Granted, they have a knock sensor but with tame cams and leaner mix.
More aggressive cams, lower the effective compression level. A richer mix makes the mix less volatile and burns cooler.
It is not only the distance of the flame travel but what it has to go over or around. Sometimes smaller motor needs twin plugging more than a big displacement motor. 2.0's are an example.
930's are also an example of this. The effective compression on these with the boost turned up is closer to 11/1 and work well with single plug because of the open chamber design and rich mix. 3.6 turbos dropped the twin plug for a single plug set up.
I am far from an expert and and sory if I sould like I play one on the Internet.
