What would cause this (cylinder wall scratches). This isn't my engine, but one I am potentially going to buy. They aren't deep enough to snag a fingernail. LS6 block billet rods, and diamond pistons built not too long ago.

 

Anyone?

 

Googled cylinder wall scuffing, various causes reported, however on chevytalk a post from 2011 has a photo of damage caused by failure to debur ring ends while fitting. At about the 12 o'clock position in your cylinder are couple of parallel marks that look very similar to the chevytalk post. That engine also was a recent build. Possible piston rock going on in addition.

 

Would it be feasible for you and do you have the means to remove the piston/rod assembly to inspect if you buy it? If you're getting the engine for a good price and you have the tools and know-how to do so, it may be worth while if you can do the disassemble/reassemble yourself. As mentioned above, it could be from rings.

 

Most definitely. I built my current setup now. This LS6 has billet 6.125 rods and diamond pistons with 2cc reliefs and stock polished crank. the guy went with a turbo setup and a cast iron LQ block. He gave this to me for $500. Its not the same look as when rings aren't deburred. In person at least.

 

Might be possible there may have been some sort of very small material in the cylinder which when it was last put together.

Will you please sell it to me for $600...