Usefulness of Oil Analysis

On Aug 21, 7:58 pm, "me" wrote:
Robert,

For educational purposes could you please describe all of the indications
that helped you pinpoint the problem you found..

Mostly it was Blackstone calling me telling me to check for a broken
pin plug. Any professional oil analysis will come with professional
evaluation of your data. The main indicator for me was progressively
higher AL in the oil.
[
-Robert

Mostly it was Blackstone calling me telling me to check for a broken
pin plug. Any professional oil analysis will come with professional
evaluation of your data. The main indicator for me was progressively
higher AL in the oil.
[
-Robert


How about just laying your eyes on the filter at every oil change -
then washing the filter in solvent, filtering the particulates out of
the solvent, and saving them in a plasticine envelope for comparison
to the next change(s)...
Total cost about 2 bucks an oil change - 1 quart of solvent and 1 Mr.
Coffee filter...

And the quart of filtered solvent can be re-used for cleaning the
landing gear...

denny

("Denny" wrote)
And the quart of filtered solvent can be re-used for cleaning the landing
gear...


And the Mr. Coffee filter?


Montblack

On Sep 26, 4:46 am, Denny wrote:
Mostly it was Blackstone calling me telling me to check for a broken
pin plug. Any professional oil analysis will come with professional
evaluation of your data. The main indicator for me was progressively
higher AL in the oil.
[
-Robert

How about just laying your eyes on the filter at every oil change -
then washing the filter in solvent, filtering the particulates out of
the solvent, and saving them in a plasticine envelope for comparison
to the next change(s)...
Total cost about 2 bucks an oil change - 1 quart of solvent and 1 Mr.
Coffee filter...

And the quart of filtered solvent can be re-used for cleaning the
landing gear...

denny

I never saw anything in the filter until the AL got very high. The oil
analysis was showing progressively higher AL for about 2 years before
that. Sadly, it did not tell me which cylinder so I ended up having to
do a boroscope every 2-6 months to watch for indications of wear. In
the end I started pumping oil in the bad cylinder which finally told
me which to pull. I really didn't want to spend $5K to have all
cylinders pulled searching for the issue.

-Robert

On Aug 19, 6:33 am, "Jim Carter" wrote:
From those that use it, I'm interested in the usefulness of starting an
oil analysis program on a big bore Continental that already has 850 SMOH
and 450 STOH on an 1100 TBO. Does it take so long to establish a
baseline and trend that it would be better to wait until OH or can an
individual engine be compared to the class as a whole?


Anyone that says oil analysis is anything other than a trending
device, should be ignored. It is difficult to say how many samples
you need to establish a trend. It depends a lot on flying habits,
weather, environmental factors, oil, consistency of operation. During
summer months, where higher operating temps are to be expected, the
analysis may show different results. Likewise, cold winter months may
too show variation. You may even observe slight variance from sample
to sample. The larger the sample base, the better off you'll be to
determine variance. From what I've read, in some cases, statistical
analysis is required to truly separate the sample to sample variance
from the actual noteworthy deviation.

Of course, the above is ignoring serious problems which can show
themselves prior to catastrophic component failure.

Oil analysis has little down side and is an excellent tool to detect
early problems. Just don't expect a couple of samples to necessarily
establish a reliable baseline; then again, I guess it depends on the
margin of error you're willing to accept too.