Posted by Kaegi [108.162.246.44] on Friday, February 24, 2017 at 19:45:13 :
In Reply to: Compression Ratio posted by Matt Wilson [162.158.69.102] on Friday, February 24, 2017 at 16:02:59 :
I disagree with your guy. flatheads are way less likely to ping than overhead valve engines. that is why they perform much better on low grade gas than over head valve will on the same fuel. running 89 octane in a flathead is like running avgas in an overhead. I have shaved .075 off the head and put in way bigger than stock cams and never had ping issues. compression at about 150 psi if I remember right. been a while