I recently began restoring a 1919 engine. I just finished cleaning the head up and everything looks great once all the mice nests were blown out. I flushed out the passages with a pressure washer. I cleaned each of what i assume are steam holes. The two corner ones and the center each allow air to be blown into the water jacket. The ones that concern me are the two small ones next to the bolt holes between the cylinders, these do not appear to enter the jacket. Are these blind holes or am i missing something?
They should go through, 5 of, head and block.
It's a good idea to get a piece of steel cable with one end flayed, put the good end in a drill, stick the flayed end into the water passages, and spin it. You want to knock out all the crud you can reach.