Ping karl and Matt: My JPI probes' ambient temperatures

[Peter R.]

karl G and Matt B, in lieu of our previous discussion about what appears to
be too low JPI CHT readings in my aircraft, I finally had the opportunity
to note the ambient temperatures for all of my JPI probes today, as the
aircraft had been sitting for a few days without the Tannis heater plugged
in.

I thought you might be interested in the readings.

Outside temperature was 53 degrees F.

Cylinder - EGT/CHT (degrees F)

1 - 50/52
2 - 51/56
3 - 51/53
4 - 54/55
5 - 50/52
6 - 52/52

Oil temp: 55

Like you, both JPI and Tornado Alley also recommended noting the ambient
temperatures as a test of the probes' proper calibrations. JPI also added
that, "The only way all probes are low at the same time simultaneously is
if the calibration is off."

I sent these results back to JPI to see if they agree that the probes are
properly calibrated.

--
Peter

[Newps]

Peter R. wrote:

>
> Cylinder - EGT/CHT (degrees F)
>
> 1 - 50/52
> 2 - 51/56
> 3 - 51/53
> 4 - 54/55
> 5 - 50/52
> 6 - 52/52
>
> Oil temp: 55


That's too wide a variation. On my EI US8A, digital oil temp and OAT I
had in my 182 all CHT's, EGT's, OAT and Oil temp were within 1 degree.

[karl gruber[_1_]]

Maybe you have the world's coolest runing engine. SOMEbody has too!

Karl



"Peter R." > wrote in message
...
> karl G and Matt B, in lieu of our previous discussion about what appears
> to
> be too low JPI CHT readings in my aircraft, I finally had the opportunity
> to note the ambient temperatures for all of my JPI probes today, as the
> aircraft had been sitting for a few days without the Tannis heater plugged
> in.
>
> I thought you might be interested in the readings.
>
> Outside temperature was 53 degrees F.
>
> Cylinder - EGT/CHT (degrees F)
>
> 1 - 50/52
> 2 - 51/56
> 3 - 51/53
> 4 - 54/55
> 5 - 50/52
> 6 - 52/52
>
> Oil temp: 55
>
> Like you, both JPI and Tornado Alley also recommended noting the ambient
> temperatures as a test of the probes' proper calibrations. JPI also added
> that, "The only way all probes are low at the same time simultaneously is
> if the calibration is off."
>
> I sent these results back to JPI to see if they agree that the probes are
> properly calibrated.
>
> --
> Peter

[Ray Andraka]

Newps wrote:

>
>
> Peter R. wrote:
>
>>
>> Cylinder - EGT/CHT (degrees F)
>>
>> 1 - 50/52
>> 2 - 51/56
>> 3 - 51/53
>> 4 - 54/55
>> 5 - 50/52
>> 6 - 52/52
>>
>> Oil temp: 55
>
>
>
> That's too wide a variation. On my EI US8A, digital oil temp and OAT I
> had in my 182 all CHT's, EGT's, OAT and Oil temp were within 1 degree.

Mine are all within 1 degree if the engine is cold, However if I have
the engine preheat turned on (I have Reiff cylinder and sump heat),
there is usually a bit more variation. I think he said that he had the
tanis heat on.

[Newps]

Ray Andraka wrote:
> Newps wrote:
>
>>
>>
>> Peter R. wrote:
>>
>>>
>>> Cylinder - EGT/CHT (degrees F)
>>>
>>> 1 - 50/52
>>> 2 - 51/56
>>> 3 - 51/53
>>> 4 - 54/55
>>> 5 - 50/52
>>> 6 - 52/52
>>>
>>> Oil temp: 55
>>
>>
>>
>>
>> That's too wide a variation. On my EI US8A, digital oil temp and OAT
>> I had in my 182 all CHT's, EGT's, OAT and Oil temp were within 1 degree.
>
>
> Mine are all within 1 degree if the engine is cold, However if I have
> the engine preheat turned on (I have Reiff cylinder and sump heat),
> there is usually a bit more variation. I think he said that he had the
> tanis heat on.


I have sump heat only. With the heat on and the Kennon nose mitten on
the temps are still the same. Every CHT and EGT is 80F and the oil temp
is 100F, it's like July in there. That's a **** poor system if you're
only seeing mid 50's with a Tanis running.

[Peter R.]

Ray Andraka > wrote:

> I think he said that he had the
> tanis heat on.

No, the Tanis heat had not been used for the three days prior to this
verification. I had mentioned the heat because when this issue came up
last week, the aircraft was plugged in and I couldn't check it.


--
Peter

[Peter R.]

Newps > wrote:

> That's too wide a variation.

3 degrees? Well, in any regard, it is not the 60 to 80 degrees below
ambient that I would have expected had there been a calibration problem.

--
Peter

[Newps]

Peter R. wrote:
> Newps > wrote:
>
>
>>That's too wide a variation.
>
>
> 3 degrees?

The table shows six degrees.

[Peter R.]

Newps > wrote:

> Peter R. wrote:
>> Newps > wrote:
>>
>>>That's too wide a variation.
>>
>> 3 degrees?
>
> The table shows six degrees.

I was comparing ambient temperature to all individual probes, not probe to
probe variations. Ambient to each probe shows no greater than a +/-3
degrees F variance.

JPI replied to my email today that the probe temperatures all looked well
within their tolerances.

--
Peter