Interesting CHT display

[8181C]

I have a M14P, 9 cylinder engine with one EMS. I have built a special harness that gives me 9 EGT probes and 3 CHT Probes. I have noticed that when I do the combined instrument (CHT and EGT), I see all 9 cylinder EGTs but the 3 CHTs cover all 9 cylinders. CHT1 (cylinders 1,2,3) CHT2 (cylinders 4,5,6), CHT3 (cylinders 7,8,9) See pix. In the separated view, I see 3 CHTs and 9 EGT bar graphs. Confused Huh Is my setup wrong?

 

[dynonsupport]

We do this on purpose. In many cases where you have less CHT's than EGT's, this means your cylinders are in one block and thus the temperature is for more than one cylinder (like a Rotax or a V8), and this makes that visually apparent.

 

[8181C]

Thank you. Any way to convert the CHTs back to display the cylinders they are connected to. Doesn't make too much sense on a round engine and if not installed on a Rotax, I imagine.
Thanks

 

[Dynon]

Not sure if this is what you're, but, there isn't a way to select only 1 EGT to overlay each of the CHTs to, if that's what you mean. What you can do is name each of the CHT thermocouple inputs something different, and then make them individual bar graphs. But they won't be overlaid on the EGT widget at all in that case.

 

[8181C]

Thanks for the help. I must be missing something because the way I believe you are describing it, the overlay CHT/EGT is not intended to have CHTs connected to the individual EGT cylinders. When displayed separately, they are correct. When combined, the CHTs don't represent the cylinders they are associated with, and thereby misleading information is being displayed. Each CHT, that I have is associated in the setup with a unique cylinder. Logic would say that when they are show in the combined format, each CHT would only show on the cylinder it is assigned to. If this is correct, what is the purpose of the combined display? :-/

 

[Dynon]

We're talking past each other a bit. Your logic works for some engines (yours), but not others (Rotaxes, which the display was originally crafted for). In those engines - like the 912 - a single CHT is really representative of a group or bank of multiple cylinders. So that's the genesis of this display. The visualization doesn't exactly work for your engine. Although, one way to go is to instrument every 3rd cylinder (1/4/7, 2/5/8, or 3/6/9, and then the CHT will represent the first, second, or third in the group). But there isn't a way to have it only show up over just that cylinder.

 

[8181C]

Ok, Thank you. Now we are on the same page. I understand. Perhaps in the next, or future update, this option would be adjusted for non-rotax engines. When you have 9 cylinders, it's good to see the duel overlay because of display space on any page less than 100%.
Thank you