No, The coating can be inside, if the PC is taken apart, or on the outside of the PC. The holes would not be coated.
Although it would probably be a good place to insolate as the holes see very hostile operating conditions, but achieving the proper bond in the hole might be very difficult. If the bond is not right, any coating will fail. I will need to consult the place that has done it for me in the past to be sure. If it is possible to reliable coat the walls of the holes, the thickness is very controlled and the hole dia could be increased to compensate for any reduction.


[/quote]You cant really increase the chamber volume without elongating the timing sequence. Rembemer that whatever changes you make the fuel has to get injected at the same time. Angling etc might make for a longer timing. Distance from the injector tip to the ball certainly has to be the same.[/quote]

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