Originally Posted by Cheburator

Sometimes I disagree with Greg...

But on this one, I am 100% with him. I have first hand experience from buying coated JE Pistons for my race car. I asked and they actually put it in writing that the super duper secret formula coating will work in the alusil bores. Engine lasted 10hrs. Of course the excuses were out straight away - not enough clearance, wrong ring gap, wrong alusil honing process, wrong engine tune etc. Did not pursue it, given the amount of variables present. All I am going to say is that all 8 pistons lost their coating on the trust faces. Not a coincidence, is it?

Bought another set of clean JE Pistons, installed dry steel liners and have been running a 434rwhp 5.4ltr GTS based engine for years now without issues. Did the same, but with clean Woessner pistons and liners in my 944 Turbo racer. Same outcome - no reliability issues with regards to block/piston assembly.

Originally Posted by slate blue

Piston coating is certainly a can of worms, I did think about getting the pistons hard chrome plated but they already had a piston coating on them so decided to go another way.

The GT3 engine and turbo engine in the 997 are nicasil as they are different engines to the other family of Porsche engines. As long as the fuel is good there is no problem. This coating was used in the last generation of F1 engines, I cannot comment on current generation engines as they are very secretive. The other coating is Sumebore,

This is used in F1 and NASCAR and Porsche engines such as the Cayenne. It is even in the Buggatti Chiron engine.

I don't think ford developed the wire transfer system first. Sumebore has been around a while. I had an enquiry about using this in the 928. I was privileged to quite a lot of information and there is many different formulas for sumebore. First the cylinder is grooved,







My cutter but requiring the special tip.



This is the factory cutter

So the coating is a purely mechanical key.

The cylinder was prepared is then sprayed with the plasma and then diamond honed lined the nicasil.

We may use this system on the replaceable liner engines. You just need a rotater, but for a block you need their machine set up on your block like the OEMs do. This would be expensive. The coating is the same thickness as the nicasil at 150 microns. The coating is diamond honed like the nicasil.