Overhaul? Lead flakes in oil - interpretation please

When I had a similar experience with metal flakes in the filter we
sent the filter off to Lycoming to find out where the metal was
coming from. Answer: cam, lifters, and something on the pistons.
Went the Factory Reman route.



"Les Sullivan" wrote in message
om...
I have a 1972 Cessna 172 with a Lycoming 0-320-E2D engine and it runs
beautifully. It is on UK private category.
The engine is "original" and total time is about 2800 hours.
The engine had a thorough top overhaul quite a few years ago, maybe
around 1500 hours (new pistons etc) and has no problems with
compression, oil consumption, vibration or indeed anything at all. It
is well looked after.
Now the but.....
At its last annual (Christmas) some metal particles were found in the
oil filter.
--------------
The lab report says:
Filter section weight 397 milligrams
Major: - lead flakes measuring 0.1mm across
Minor: - blank
Traces: - Aluminium alloys - corroded fragments measuring up to 1.6 x
0.5mm
Iron - 0.5%
Nickel - 0.5%
Chromium steel such as sae8617,8620 or 8740 flakes measuring up to
0.9mm across
Iron - A low alloy carbon steel with no significant alloying
constituents such as sae 1010 slivers measuring up to 0.9 x 0.3mm
Miscellaneous - mainly fine particles.
--------------
I think it now means a complete overhaul to zero time.
The choice seems to be:
a) Factory Zero timed engine
b) Factory overhauled engine
c) Have my own engine worked on

What are your views about which way to go with this?

It is awfully tempting to keep the plane running and cut open the new
oil filter at, say, 20hours and see if there are any more particles.
As I said, compressions, oil pressure, power etc. are all good.

Maybe my greatest fear is that if I keep it flying, there may be
damage caused to the crankshaft or something which causes a big price
increase at overhaul due to the part being rejected.

Any advice / comments greatly appreciated.

Les

What was it said a few months ago on a thread like this? "It's not time to
overhaul an engine until you can read the serial numbers on the metal found in the oil
screen"

Seriously though, if it's a 32 year old engine at 2800 hours making metal, it's a
non-too-subtle statement that it's time.

-Cory
--
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In article ,
wrote:

What was it said a few months ago on a thread like this? "It's not time to
overhaul an engine until you can read the serial numbers on the metal found
in the oil
screen"

Seriously though, if it's a 32 year old engine at 2800 hours making metal,
it's a
non-too-subtle statement that it's time.


Being a Lycoming, it is likely suffering from spalling tappets and a
worn camshaft.

Lycomings, due to their cam-above-the crankshaft design, tend to collect
moisture over the front lobes of the cam -- especially if the plane has
been infrequently flown.

It sounds like overhaul time!

I have a 1972 Volkswagon with a Volkswagon engine and it runs beautifully.
The engine is "original" and the speedo shows 280,000 miles (total time 2800
hours times 100 miles per hour). The engine had a thorough top overhaul
quite a few years ago, maybe around 150,000 miles (new pistons etc) and has
no problems with compression, oil consumption, vibration or indeed anything
at all. It is well looked after and has won many quarter mile drag races, at
least one a week!

Now the but.....

At its last annual (Christmas) some metal particles were found in the oil
filter.

Any advice / comments greatly appreciated.

"Believe it or not?"

;)

Peter

(Les Sullivan) wrote in message . com...

At its last annual (Christmas) some metal particles were found in the
oil filter.
--------------

My take on it:

The lab report says:
Filter section weight 397 milligrams
Major: - lead flakes measuring 0.1mm across
Bearing babbitt
Minor: - blank
Traces: - Aluminium alloys - corroded fragments measuring up to 1.6 x
0.5mm
Pistons, piston pin buttons, camshaft bearings
Iron - 0.5%
Piston rings
Nickel - 0.5%
Cylinder barrels
Chromium steel such as sae8617,8620 or 8740 flakes measuring up to
0.9mm across
Crankshaft, I think
Iron - A low alloy carbon steel with no significant alloying
constituents such as sae 1010 slivers measuring up to 0.9 x 0.3mm
Bearing shell backs
Miscellaneous - mainly fine particles.
--------------
I think it now means a complete overhaul to zero time.
Yup.
The choice seems to be:
a) Factory Zero timed engine
Expensive
b) Factory overhauled engine
Best, since it still has mostly new parts. Only crankcase and
maybe crank are reused
c) Have my own engine worked on
Don't do it. They'll find a corroded, scored-up crank ($7000),
cam shot ($?) and so on. Will cost more than factory O/H. Big risk

It is awfully tempting to keep the plane running and cut open the new
oil filter at, say, 20hours and see if there are any more particles.
As I said, compressions, oil pressure, power etc. are all good.

Maybe my greatest fear is that if I keep it flying, there may be
damage caused to the crankshaft or something which causes a big price
increase at overhaul due to the part being rejected.

Biggest fear should be catastrophic failure. O-320s are known for
swallowing corroded valves.

Dan