Dad's air compressor blew up. He took off the cylinder head to find a screw or two rattling around inside the compression chamber. I happily offered to clean up the damage.
Firstly, I sandblasted out all the dirt and grime, and flattened the seating area on a flat granite block with 1000 grit sand paper.
The intake valves were easy - chase the 8 threaded holes with the appropriate tap. It was a very odd sized - #5-40. I use #4, 6, 8, and 10 all the time, but this is my first opportunity to work with a #5. I had to go to my machinist buddy to get a #5 modified bottoming tap.
The exhaust valves needed to upsize a little. The threads were bad, so I went from a #5-40 to a #8-32 button head stainless steel screw. Drill out the hole, thread it, and also drill out the valves and valve retainers to the OD of the screw.
I think this should now work nicely. Delivery is set for Easter weekend.
