Jaba
oggers, let me make it really simple.
YOUR hypothesis is true….until.
The valve temperature "tracks" the EGT, because as the mixture at any given mass airflow is leaned, the EGT goes up AND the CHT goes up. But why does the CHT go up? Because the peak cylinder pressures go up. Just like your air compressor in the garage.
Now at the moment your hypothesis is true right up until the moment they stop tracking each other and diverge. Hypothesis BUSTED. end of argument
Haha, you wish. I have explained why the valve temp peaks just before the EGT twice already. It is because: "the spread between where CHT and EGT peak as a function of mixture means the valve temp will not peak precisely at either but between them." The valve is heated by the working fluid and cooled by the head -and ultimatley the air. Therefore one would expect the valve temp to peak between peak EGT and peak CHT.
Now when the CHT tracks the valve temp hypothesis is tested in exactly the same way, and it does not diverge, it follows the valve temperature…..
...but it does "diverge" as we can see:
...what can you make from that?
..that you really really want the report to show no "divergence" between CHT and valve temp even though it doesn't!
Because when Lycoming did their test with far newer equipment they plotted even better curves showing this in detail. I do not have them at hand, but in several weeks I will be right there in the dyno room and will surely be able to get them, if I remember.
We shall see. However, John Deakin already tried to make this point with Lycoming 'data' so maybe we already have it:
"It should be intuitively obvious then, that the valve temperature will correspond most closely with the cylinder head temperature (not the EGT), and indeed, old data from Lycoming (1966) confrirm this" he wrote, and here's the 'data':
...I added the pecked lines. There isn't actually a curve on there for the valve, but anyway he says:
"Note that CHT, valve guide, and valve head temperature all increase together, all peak at roughly the same point on the mixture curve (just rich of peak EGT), and all fall together."
...and they do sort of peak in the same place but there is a trend; The valve seat peaks leaner and hotter than CHT, and the guide leaner and hotter still and very much closer to peak EGT than peak CHT. And if the valve was on there it would definitely be hotter than the guide. And yet the APS opinion is that has nothing to do with the exhaust gas temperature.
I think most people can understand that if the guide - which isn't even in the combustion chamber - is running hotter than the valve seat, and the cylinder head, it is because it is being heated by the hot exhaust flow. Or bearing in mind that only 25% of the valve heat goes through the guide while 75% goes through the seat, why isn't the seat hotter than the guide? Because of the exhaust gas.
I find it very strange that you persist in arguing against this ground truth.