Again, you have an issue where water (coolant) is leaking into the cylinder past the exhaust valve. Another big issue I see is that someone sprayed copper coat onto the gasket which is incorrect. You should NEVER spray copper coat on a Cometic gasket as it will cause sealing problems. The ONLY gasket that will get sprayed is a steel head shim (block side only) or a head gasket with one or both sides metal. You never spray a composite head gasket as it will affect the sealing ability of the gasket. Cometic gaskets are installed dry as the black surfaces are a rubber layer and will not seal properly if not installed dry. This is not the cause of the water intrusion because the evidence shows that it came in thru the exhaust valve. Replace any bad valves, do a complete valve job, surface the heads to the proper Ra finish with a mill using a PCD insert, reinstall with new Cometic head gaskets (install dry, no sealer), and ensure any/all exhaust bolts/studs that go to water have sealer on the threads. I use a Teflon thread sealer by Permatex, and if studs/nuts, I put an anti-seize on the threads for the manifold nuts.