I really appreciate the personal response, and do not want to hijack your thread, so I will only ask a tiny bit more, and then start a build thread so as not to impose on others. For the project I am starting (52cc diesel, horizontal, crosshead) I was planning to use 12L14 for the head (with water passages), 316 stainless for the valves, normalized 4130 DOM tube for the cylinder (with water jacket), purchased Tanaka 1.5 mm thick rings, and possibly Nitronic 60 stainless for the piston (very good galling resistance and I have some of it on hand). Your endorsement of C544 for the valve guides checks off another box in the material list. I admit that I'd rather work with 7075 for the head, but it is a simple design so the 12L14 will still be easy to work. I am guessing that you will say that with a 12L14 head, either the C544 or the 12L14 head material will be suitable. Again, thank you so much for your response. The freedom with which you and all the forum members share their knowledge is much appreciated.
Graham,The drawing of the camshaft shows:-
(Currently set up to machine key ways in camshaft but)
Center bottom, order of lobes on camshaft is different to that of top right picture.
Any idea which is correct?