There appears to be a small amount of detonation marks at very top ridge, but the dark pits a little lower in the bore under the combustion ring are just porosity pits from the original casting. Those are nothing to worry about, but the lighter specks further down near the transfer ports are too blurry to make out from the photo. I think they are also just porosity pits that are catching the light and shining, but not 100% about that.
From Millennium Technologies website -
Porosity is gas trapped in the base metal aluminum during casting. These “holes” are exposed when the cylinder is machined or subjected to various chemicals in the plating process. The pits are usually small in size, and in good castings few and far between. When kept under acceptable levels, porosity will not adversely affect the performance or longevity of the engine. In fact, it will improve lubrication. The pits will not cause the coating to peel, nor will a ring hook on them. As far as our specifications on porosity, our cylinders carry a lifetime warranty against defects in materials and workmanship. Therefore, through extensive testing we have found that porosity is a cosmetic problem only. In our pursuit to have both cosmetic and functional perfection we do everything possible to remove these pits. In some cases this is not possible, so we release the cylinder only in cases where it will not affect performance
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