More oil lube will fix the problem.

While running a break in, did you ever notice the engine suddenly runs a bit heavy and slowly comes back to normal again? That was such a moment the piston did grow and polished off again. For several years I was involved with an engine development and have broken in many engines and have seen this grow many times. I was told some manufacturers put their pistons or piston material in an oven to give them a 1st heat treatment to lower this effect.

So a grown piston can be fixed with some oil? Oh wow!

Do you have a franchise or stock in an oil co? Would almost seem that way. Contrary to what you might believe, more oil isn't always the answer.