JPI Engine Data Analysis Questions

[Jay Honeck]

I've had the EDM-700 in my panel since 2002. I was able to download
the engine data once, way back when the unit was new, but then my old
laptop's battery died, and I never could remember to bring it (or its
power cord) to the hangar. And, quite frankly, IMHO the saved data
was presented in a less-than-useful format. So, I never downloaded
it again.

Fast forward to 2007, and I've got a new Vista laptop. After half a
dozen failures, I finally got JPI's new(er) EZTrends software to
work. (First my old serial-to-USB cable wasn't Vista-compatible, then
the old EZSave software wasn't Vista compatible, then the COM ports
weren't configured right, then...)

After all this tinkering and updating, I was at last able to download
my last 22 flights, going back to October. The new EZTrends software
is very cool (and far superior to the old EZSave), showing a snapshop
of each cylinder's EGT and CHT taken every 6 seconds throughout the
flight. Using built-in features, you can graph & view maximums,
minimums, averages, and trends of all parameters, including outside
air temperature and oil temperature.

The graphs seem to paint a rosy picture. At no point did any cylinder
exceed maximum allowable temperatures. All the averages are nice,
straight lines, declining somewhat as we entered the colder months.
There appear to be no alarming trends.

So, to you computer gurus out there -- now what? Should I be looking
for anything other than peaks and trends? Is there any parameter, or
combination of parameters to watch out for? What do you guys do with
your data?

Thanks!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Stan Prevost[_1_]]

What I have started doing is looking at average, peak-to-peak variation, and
standard deviation on each channel, over a half-hour or so of stable cruise.
I am watching for any trend or sudden change in variability of data on a
channel. Doesn't tell all, but I hope it will alert me to something going
awry, whether it is engine or sensor. And it was easy to do in Excel.

Stan


"Jay Honeck" > wrote in message
...
> I've had the EDM-700 in my panel since 2002. I was able to download
> the engine data once, way back when the unit was new, but then my old
> laptop's battery died, and I never could remember to bring it (or its
> power cord) to the hangar. And, quite frankly, IMHO the saved data
> was presented in a less-than-useful format. So, I never downloaded
> it again.
>
> Fast forward to 2007, and I've got a new Vista laptop. After half a
> dozen failures, I finally got JPI's new(er) EZTrends software to
> work. (First my old serial-to-USB cable wasn't Vista-compatible, then
> the old EZSave software wasn't Vista compatible, then the COM ports
> weren't configured right, then...)
>
> After all this tinkering and updating, I was at last able to download
> my last 22 flights, going back to October. The new EZTrends software
> is very cool (and far superior to the old EZSave), showing a snapshop
> of each cylinder's EGT and CHT taken every 6 seconds throughout the
> flight. Using built-in features, you can graph & view maximums,
> minimums, averages, and trends of all parameters, including outside
> air temperature and oil temperature.
>
> The graphs seem to paint a rosy picture. At no point did any cylinder
> exceed maximum allowable temperatures. All the averages are nice,
> straight lines, declining somewhat as we entered the colder months.
> There appear to be no alarming trends.
>
> So, to you computer gurus out there -- now what? Should I be looking
> for anything other than peaks and trends? Is there any parameter, or
> combination of parameters to watch out for? What do you guys do with
> your data?
>
> Thanks!
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"

[Jay Honeck]

> What I have started doing is looking at average, peak-to-peak variation, and
> standard deviation on each channel, over a half-hour or so of stable cruise.
> I am watching for any trend or sudden change in variability of data on a
> channel. Doesn't tell all, but I hope it will alert me to something going
> awry, whether it is engine or sensor. And it was easy to do in Excel.

In another forum a guy mentioned that you want to look for
fluctuations up and down in EGT, as it is an early indicator of a
sticky valve.

The question, of course, is what's a "normal" fluctuation, and what's
"abnormal"... Looking at my data most cylinders go up and down 10 to
15 degrees pretty regularly...

I'm assuming that's "normal" because they're all doing it -- but it
would be good to see some hard data on what these lines actually mean.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Stan Prevost[_1_]]

Hope the formatting doesn't get mangled. It looks OK as I enter it.

This is a typical snapshot analysis of data from my EI UBG-16 analyzer. It
covers about 23 minutes of cruise data. Columns are analyzer channels
(EGT1, CHT1, EGT2, ........., TIT, Oil, Cowling Temp, and an unused
channel).

Top row is peak-to-peak variation (max minus min). Center row is average.
Bottom row is standard deviation.

5 3 5 2 3 2 3 2 5 2 4 1 2 1 1
1408 269 1443 312 1460 258 1438 281 1431 236 1361 240 1605 195 122
1.6 0.7 0.8 0.6 0.8 0.5 0.8 0.6 1.3 0.6 1.4 0.5 0.8 0.4 0.5


Lycoming TIO540-AH1A, 800 hrs since new, LOP (no GAMIs).


"Jay Honeck" > wrote in message
...
>> What I have started doing is looking at average, peak-to-peak variation,
>> and
>> standard deviation on each channel, over a half-hour or so of stable
>> cruise.
>> I am watching for any trend or sudden change in variability of data on a
>> channel. Doesn't tell all, but I hope it will alert me to something
>> going
>> awry, whether it is engine or sensor. And it was easy to do in Excel.
>
> In another forum a guy mentioned that you want to look for
> fluctuations up and down in EGT, as it is an early indicator of a
> sticky valve.
>
> The question, of course, is what's a "normal" fluctuation, and what's
> "abnormal"... Looking at my data most cylinders go up and down 10 to
> 15 degrees pretty regularly...
>
> I'm assuming that's "normal" because they're all doing it -- but it
> would be good to see some hard data on what these lines actually mean.
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"

[Stan Prevost[_1_]]

Well, I see it did get mangled. Let me try to fix it.

5 3 5 2 3 2 3 2 5 2
4 1 2 1 1
1408 269 1443 312 1460 258 1438 281 1431 236 1361 240 1605 195 122
1.6 0.7 0.8 0.6 0.8 0.5 0.8 0.6 1.3 0.6 1.4
0.5 0.8 0.4 0.5

That's a little better, barring further mangling.


"Stan Prevost" > wrote in message
...
> Hope the formatting doesn't get mangled. It looks OK as I enter it.
>
> This is a typical snapshot analysis of data from my EI UBG-16 analyzer.
> It covers about 23 minutes of cruise data. Columns are analyzer channels
> (EGT1, CHT1, EGT2, ........., TIT, Oil, Cowling Temp, and an unused
> channel).
>
> Top row is peak-to-peak variation (max minus min). Center row is average.
> Bottom row is standard deviation.
>
> 5 3 5 2 3 2 3 2 5 2 4 1 2 1 1
> 1408 269 1443 312 1460 258 1438 281 1431 236 1361 240 1605 195 122
> 1.6 0.7 0.8 0.6 0.8 0.5 0.8 0.6 1.3 0.6 1.4 0.5 0.8 0.4 0.5
>
>
> Lycoming TIO540-AH1A, 800 hrs since new, LOP (no GAMIs).
>
>
> "Jay Honeck" > wrote in message
> ...
>>> What I have started doing is looking at average, peak-to-peak variation,
>>> and
>>> standard deviation on each channel, over a half-hour or so of stable
>>> cruise.
>>> I am watching for any trend or sudden change in variability of data on a
>>> channel. Doesn't tell all, but I hope it will alert me to something
>>> going
>>> awry, whether it is engine or sensor. And it was easy to do in Excel.
>>
>> In another forum a guy mentioned that you want to look for
>> fluctuations up and down in EGT, as it is an early indicator of a
>> sticky valve.
>>
>> The question, of course, is what's a "normal" fluctuation, and what's
>> "abnormal"... Looking at my data most cylinders go up and down 10 to
>> 15 degrees pretty regularly...
>>
>> I'm assuming that's "normal" because they're all doing it -- but it
>> would be good to see some hard data on what these lines actually mean.
>> --
>> Jay Honeck
>> Iowa City, IA
>> Pathfinder N56993
>> www.AlexisParkInn.com
>> "Your Aviation Destination"
>

[Stan Prevost[_1_]]

Dang it, it got worse!


"Stan Prevost" > wrote in message
...
> Well, I see it did get mangled. Let me try to fix it.
>
> 5 3 5 2 3 2 3 2 5 2
> 4 1 2 1 1
> 1408 269 1443 312 1460 258 1438 281 1431 236 1361 240 1605 195 122
> 1.6 0.7 0.8 0.6 0.8 0.5 0.8 0.6 1.3 0.6 1.4
> 0.5 0.8 0.4 0.5
>
> That's a little better, barring further mangling.
>
>
> "Stan Prevost" > wrote in message
> ...
>> Hope the formatting doesn't get mangled. It looks OK as I enter it.
>>
>> This is a typical snapshot analysis of data from my EI UBG-16 analyzer.
>> It covers about 23 minutes of cruise data. Columns are analyzer channels
>> (EGT1, CHT1, EGT2, ........., TIT, Oil, Cowling Temp, and an unused
>> channel).
>>
>> Top row is peak-to-peak variation (max minus min). Center row is
>> average. Bottom row is standard deviation.
>>
>> 5 3 5 2 3 2 3 2 5 2 4 1 2 1 1
>> 1408 269 1443 312 1460 258 1438 281 1431 236 1361 240 1605 195 122
>> 1.6 0.7 0.8 0.6 0.8 0.5 0.8 0.6 1.3 0.6 1.4 0.5 0.8 0.4 0.5
>>
>>
>> Lycoming TIO540-AH1A, 800 hrs since new, LOP (no GAMIs).
>>
>>
>> "Jay Honeck" > wrote in message
>> ...
>>>> What I have started doing is looking at average, peak-to-peak
>>>> variation, and
>>>> standard deviation on each channel, over a half-hour or so of stable
>>>> cruise.
>>>> I am watching for any trend or sudden change in variability of data on
>>>> a
>>>> channel. Doesn't tell all, but I hope it will alert me to something
>>>> going
>>>> awry, whether it is engine or sensor. And it was easy to do in Excel.
>>>
>>> In another forum a guy mentioned that you want to look for
>>> fluctuations up and down in EGT, as it is an early indicator of a
>>> sticky valve.
>>>
>>> The question, of course, is what's a "normal" fluctuation, and what's
>>> "abnormal"... Looking at my data most cylinders go up and down 10 to
>>> 15 degrees pretty regularly...
>>>
>>> I'm assuming that's "normal" because they're all doing it -- but it
>>> would be good to see some hard data on what these lines actually mean.
>>> --
>>> Jay Honeck
>>> Iowa City, IA
>>> Pathfinder N56993
>>> www.AlexisParkInn.com
>>> "Your Aviation Destination"
>>
>

[Steve]

The information I received in the Savvy Aviator seminar is:

A regular, one minute cycle of about 50 to 100 degrees (I think that
was the number) of EGT for one cylinder is an indication of a burned
(not sticky) exhaust valve that will fail, typically 100 hours after
first indications. The mechanisim seems to be that the valve rotates
as it goes up and down, about one rpm. Every time the nick in the
valve meets the nick in the valve seat extra gas escapes. Once you've
seen the plot of this, it shows up like a neon light.

- Steve Mills
N2679V 'Vicky" @ PDK
Cardinal RG '75



On Mon, 10 Dec 2007 06:18:02 -0800 (PST), Jay Honeck
> wrote:

>> What I have started doing is looking at average, peak-to-peak variation, and
>> standard deviation on each channel, over a half-hour or so of stable cruise.
>> I am watching for any trend or sudden change in variability of data on a
>> channel. Doesn't tell all, but I hope it will alert me to something going
>> awry, whether it is engine or sensor. And it was easy to do in Excel.
>
>In another forum a guy mentioned that you want to look for
>fluctuations up and down in EGT, as it is an early indicator of a
>sticky valve.
>
>The question, of course, is what's a "normal" fluctuation, and what's
>"abnormal"... Looking at my data most cylinders go up and down 10 to
>15 degrees pretty regularly...
>
>I'm assuming that's "normal" because they're all doing it -- but it
>would be good to see some hard data on what these lines actually mean.

[Jay Honeck]

> A regular, one minute cycle of about 50 to 100 degrees (I think that
> was the number) of EGT for one cylinder is an indication of a burned
> (not sticky) exhaust valve that will fail, typically 100 hours after
> first indications. The mechanisim seems to be that the valve rotates
> as it goes up and down, about one rpm. Every time the nick in the
> valve meets the nick in the valve seat extra gas escapes. Once you've
> seen the plot of this, it shows up like a neon light.

Interesting stuff!

If you've ever seen the flight engineer's station of a Lockheed
Constellation, it's amazing to see the engine monitors they had 60
years ago. It's basically an oscilloscope that they could switch from
one engine to the next, and they had a huge book with pictures of
readouts that they constantly referred to for engine diagnosis. (I
was fortunate enough to log a little right-seat time in the MATS
Connie, before they mounted it on a stick in South Korea.)

If the screen looked like *that*, it was *this* problem. If it looked
like *this*, it was *that* problem. It was amazing how they discerned
what was going on from a squiggly line on a cathode ray tube.

THAT is the kind of book I wish JPI would publish. If the graph looks
like THIS, you've got a valve going bad. It it looks like THAT,
you've got morning sickness. The articles on AvWeb get close to that
-- but why isn't JPI doing it?

Don't tell me, let me guess: "liability"...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Rip[_2_]]

Jay Honeck wrote:
> THAT is the kind of book I wish JPI would publish. If the graph looks
> like THIS, you've got a valve going bad. It it looks like THAT,
> you've got morning sickness. The articles on AvWeb get close to that
> -- but why isn't JPI doing it?

Jay, you can download the manual for the Insight "GEM" series at:
http://www.insightavionics.com/
It has the pictures you want.

Rip

[Jay Honeck]

> Jay, you can download the manual for the Insight "GEM" series at:http://www.insightavionics.com/
> It has the pictures you want.

Thanks! The actual link is:

http://www.insightavionics.com/pdf%20files/GEM%20GUIDE.pdf

Pages 67 through 77 have pictures of the instrument when different
things are going wrong in flight. It's specifically for the Insight
GEM, but that instrument is virtually identical to the EDM-700. Very
useful information, indeed.

Now, what we need are pictures of the corresponding graphs (from the
downloaded data) that match up to the specific problems depicted.
THAT would be very useful indeed, to be able to recognize the problem
signs just from the graphs -- in case you missed the indications in-
flight.

Any ideas?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Paul kgyy]

>
> So, to you computer gurus out there -- now what? Should I be looking
> for anything other than peaks and trends? Is there any parameter, or
> combination of parameters to watch out for? What do you guys do with
> your data?
>
On my IO360, max to min EGTs never have a range of more than 70-80 deg
in cruise, often less. On one flight this summer, I noticed that #4
EGT was running about 100 deg higher than normal. Checked both mags
in flight, sure enough, right mag a little rough. 10 minutes later,
everything was fine. Next flight, everything still fine.

I downloaded data from the last several flights and looked at the
data. Sure enough, every now and then #4 would jump up for a few
minutes, then resume normal operation.

I dropped it off at the shop and asked for a check of the plugs.
Turned out one plug wire wasn't entirely tight. That plug was fouled
from intermittent firing. Cleaned all plugs, all fine.

Without the JPI, I would never have noticed, as mag runup on the
ground was always fine.

So what you're looking for is "what's normal" so that you can spot
"this isn't normal".

[Mike Noel]

That is great information to have available. One side remark, I've blown
out intake gaskets from backfires during bad mag checks. Now I usually wait
until I'm on the ground before checking the mags.

--
Best Regards,
Mike

http://photoshow.comcast.net/mikenoel


"Paul kgyy" > wrote in message
...
> >
>> So, to you computer gurus out there -- now what? Should I be looking
>> for anything other than peaks and trends? Is there any parameter, or
>> combination of parameters to watch out for? What do you guys do with
>> your data?
>>
> On my IO360, max to min EGTs never have a range of more than 70-80 deg
> in cruise, often less. On one flight this summer, I noticed that #4
> EGT was running about 100 deg higher than normal. Checked both mags
> in flight, sure enough, right mag a little rough. 10 minutes later,
> everything was fine. Next flight, everything still fine.
>
> I downloaded data from the last several flights and looked at the
> data. Sure enough, every now and then #4 would jump up for a few
> minutes, then resume normal operation.
>
> I dropped it off at the shop and asked for a check of the plugs.
> Turned out one plug wire wasn't entirely tight. That plug was fouled
> from intermittent firing. Cleaned all plugs, all fine.
>
> Without the JPI, I would never have noticed, as mag runup on the
> ground was always fine.
>
> So what you're looking for is "what's normal" so that you can spot
> "this isn't normal".

[Jay Honeck]

> Without the JPI, I would never have noticed, as mag runup on the
> ground was always fine.

Yep, the JPI is an awesome diagnostic tool. When we lost our #2
cylinder (due to lead fouling and a faulty spark plug wire) climbing
out of Titusville, Florida, it took only a glance to know precisely
what was happening.

Without the EDM-700, I wouldn't have had a clue, other than the rough-
running engine.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"