Bought a cylinder head with a known flaw thinking it could be fixed. It had a tiny hole in the combustion chamber. Found an expert aluminum welder. Said he'd have to grind it out first then weld fill it to do it right. When he ground it out, he found the tip of a carbide drill bit at the bottom.
Go figure. I can't imagine how anyone could do that to a cylinder head by accident. Guy in my car club speculated that it was done intentionally by the manufacturer to prevent selling it due to some other flaw. Can't detect any other flaw though.
Now I have this blob of weld, as expected, rather than a hole in the head. Seems the head should be milled to make the mating surface perfectly flat (been advised no more than 0.005") and that inside of the combustion chamber should be smoothed out and matched with a handheld rotary porting tool like a Dremel tool.
Sound good? Which should come first, the milling or the hand-held touch-up? I'm thinking the hand-held touch-up.