Piston skirt coating peeled off after break in

Hi

We're building a 4G63 engine with Wiseco pistons with skirt coating.

The engine run for a few kms to break it in and has been diassembled in order to verify that everting was fine.

We noticed that the coating in the pistons has dissapeared in both sides of the skirt (all four pistons look very similar)

We've also noticed that the coating is easily removable. Just passing your nail over it will produce a noticeable scratch in the coating. We'see seen your

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and we learnt that some coatings are there to stay whereas others are not that permanent.

Do you happen to know whether this Wiseco pistons are one type or the other?

Do you see a problem running the pistons as they are or should they be discarded to be on the safe side?

Thanks in advance!

It would probably be more effective to contact Wiseco directly to enquire about this.

Some coatings are designed to be a permanent coating, others are used to reduce wear/friction when running the engine in, but there's not much info'.

Ah, seems to be an "Armorglide" coating, which is a dry film coating - https://wiseco.com/blog/piston-coatings