Cylinder wall problems ( never seen anything like it)

Okey I finally took the thumb out of my a## and checked the engine block.
I took a Hammer and cracked the cylinder walls in big pieces.
The thinnest spot I could find was 0.110
I then took my new sonic tester and calibrated it with the cylinder wall pieces so it would be as accurate as possible and I did not find any thinner spot then 0.110". So I think that the thickness was not the issue, and all the discoulor on the walls I think was caused by the octane booster I´d had used ( never thought of that before)
Have a friend that had the exact same issue but he ran his engine on E85 fuel.
Again thanks for all the input.