Combustion chamber deformed

[gamiller31]

I am rebuilding my 4G63, and after cleaning the head(most of it), I noticed a blister like hump in the combustion chamber next to the exhaust valve. Have you experts seen this before? If so, should I grind it down? What is the possible cause of this. There is a water passage close to this spot, but not sure whether it is too close to repair or not. Sorry for the fuzzy pictures, but I am not a photographer. TIA for taking time to reply.

 

[gamiller31]

Anybody?? Anyone seen this before, the high spot next to the valve?? Is it just casting imperfection??

 

[Defiant]

Yeah. Grind it off.

And never bump a thread again.