Polaris Nikasil Coating

Hey, I have a 2013 RZR 900 with a +3mm Big Bore from Rev6. After less than 100 miles the engine started smoking. When I got it apart, I found that the nikasil coating had a large chunk taken out of it. I am curious what could have caused this. Is this a problem with the part or with assembly? I am also curious where I can get a new cylinder of this size. I can not find any of them from the higher end companies. The only ones I can find are from cheap Chinese companies. Are the cheap ones any good?