Detonation, or something else?

[Laga]

Anybody ever see marks like this in the cylinder?

They are in all 8 cylinders with this one being the worst. They are also in the same location in the cylinders, with them being what would be the outside of the cylinder when sitting in the car. They are more like discoloration than scores or scratches as they are smooth and cannot be felt. Otherwise the block is in very good shape. The engine builder thinks they are from detonation. I’m not so sure. Pistons do not show any sign of detonation. Any thoughts? I did have a 93 octane performance tune from Bama from ‘05 to ‘16. Then a Brenspeed tune with the install of the Edelbrock supercharger in ‘16 and then E85 Lito tune from ‘18 to present. I’m getting forged bottom installed.

 

[msvela448]

It almost looks like water was sitting in the cylinder for a prolonged amount of time. Kind of like an etching effect. Should be fine with some honing, I think.

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[Laga]

It almost looks like water was sitting in the cylinder for a prolonged amount of time.

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That’s what I was thinking. E85 produces more water than gasoline. And, the car is not driven every day.

 

[Dino Dino Bambino]

Detonation would cause increased rocking of the pistons in the bores at TDC resulting in scoring of the cylinders at the front and rear.
Those marks definitely aren't from detonation as they're in the wrong place for that. At worst you might need to hone the cylinders a little to remove any glazing.

It almost looks like water was sitting in the cylinder for a prolonged amount of time. Kind of like an etching effect. Should be fine with some honing, I think.

This.