heres what information i would like to gather. i think it would be good for us all with non compensated cht gauges to know.

on a non compensated gauge what are your (gauge) cht readings at:

1 what ambient temp. is it? high or low humidity?
2 what is the cht reading? at cruise? at idle?
3 how much does your reading raise under load or cross wind or headwind?
4 what engine cc & cam

mike

1 what ambient temp. is it? high or low humidity?
* 90's to 100, medium/low humidity.
2 what is the cht reading? at cruise? at idle?
* 345-350 @ cruise, 340 @ idle
3 how much does your reading raise under load or cross wind or headwind?
* Max 5 to 10 degrees. I've never seen it over 350 even in 100+ Texas heat.

Mike, I am not sure if I understand your question or agree with the utility of the information. Noncompensated CHT is always actual plus ambient but I don't think that is what you are asking is it? WOT on mine should be no greater than 1400 F. on a noncompensated guage that would be 1400 F + ambient. But my engine is a 2270 and has headers. I am pretty sure CHT is going to depend on what engine we are talking about and how it is equipped. At cruise my CHT is much less than that, and under acceleration it varies wildly... I am most concerned with WOT as I have carbs. Perhaps this guage would be more stable in an EFI car?
Perhaps Jake will chime in. In the 914 info section at the top of the page you can navigate to an article Jake wrote about CHT.

Please tell me you are talking about EGT and not CHT when you are stating that your are 1400 F+....that is a bit too hot...by about 1100 degrees.

What I believe he is asking is to just a feeling for how accurate his specific gauge really it.

Rich

i think you must be refering to egt's... no? i am however unclear on how much temperature differance to add to my non compensated gauge. for example i've been told they are at 0 difference at 70* ambiant temperature. if that is true then my 215* reading on a 95* day would be 235* (215*x 25*= 240*).

mike

yes, i'm trying to figure my acual temp readings. AND i added #4 to my lead question, i may as well get some info on temp. ranges of different cam/cc combo.'s. this could be helpful to all the other engine builders out there. i know the 2056 w/ 9550 cam we built seems exceptional in the cooling dept. there may be other factors involved in the build too, i dont know.

mike

Yes. EGT. Illustration to show that most of our engines vary. If the noncompensated guage varies depending on ambient it simply isn't accurate enough. Should be ambient plus reading to be accurate.

Rob,
There are some gauges, not senders, that use 70 degrees as a baseline and call that zero.
Now it its 90 degrees outside and the reading is 250, the gauge is still accurate, its just a matter of doing some math.

250 minus 70 for the baseline settings of the virtual "zero"
the what to do with the 20 additional degress of variation....hmmmm

this is gauge specific and the manufacturer should provide you with the correct instructions regarding how to read the gauge.

BTW, this is typical airline pilot stuff, so maybe one of the flyboys will kick in here...

Rich

I don't remember seeing a gauge like that on this thing. Could I have missed something all those years?

250 minus 70? wouldn't it be plus?? for example if it's colder than baseline of 70* wouldn't that be minus?

also if there is a baseline then would't the formula be based off the number differance above or below the base temp. of 70*? like my example of:

95* ambient = (+25* differance) + 215* (guage reading) = 240* (compensated temp.)

25* + 215* = 240*

i think he's refering to the jet blue or alaska airline series
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