Some recent posts about heads brought to mind a question? There are heads I see that seem to have been surfaced at some point. There are probably variations in each casting. At some point a head is just to used up.
I would like to know if there is a reliable way to visibly examine a head and I.D. the ones that just don't have enough material left for further milling to restore a level surface.
I think it is a judgement call. Not all heads are cast the same. 1917 Canadian high cylinder heads have a thicker deck area and can probably be milled 3/16".
I saw a model T head milled 1/4 inch. It was re-ally pushing the limit in my opinion. It had begun to enlarge around the water jacket passages. I never heard if it worked or not. One of the earlier low heads I have looks to have been milled a lot, but I have not measured it to see how much. Guess I should. I plan to use it and see what happens.
Drive carefully, and enjoy, W2
I guess I should also mention that usually when heads are milled a lot like this, it is to raise the compression. When milling to make a proper, flat, fit, they are usually only milled a small amount (often about .010 inch). I do not like milling heads a bunch for compression reasons only. The one I have was like this when I got it years ago.
Drive carefully, and enjoy, W2