Balloon
Except for the fact that valve temperature does not track EGT.
Hmm. As I have posted a couple of times already neither EGT nor CHT correlates perfectly with the valve temp on its own. But together they do. A sense of proportion is called for here. No, the valve temp does not exactly track EGT - I have never said that - but it does correlate very well. Yes, valve temp peaks slightly rich of EGT but that is because it is also inlfuenced by CHT. That is what the engineering literature tells us and it is what the NACA report shows us.
As long as you keep misrepresenting that I will keep correcting you.
Here again is the graph:
The position that you and Walter Atkinson have taken (and as far as I can tell it is an APS thing) is flat out wrong. Let me repeat your position
"EGT and exhaust valve temperature are not in any way related". Wrong.