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"