Engine making metal...the rest of the story

[Ted Waltman]

Some time ago, I reported that my M-14P was showing metal in the
Aviation Development Corporation (ADC) oil screen. As I reported, some
folks told me it wasn't any big deal, as these engines are legendary
tough. Another guy told me he wouldn't even taxi it. I talked to folks
all over the country about this, including the ADC folks. This was
supposedly a brand new engine with, at the time, about 120 hours.

Finally I decided that I'd check the compression and have the engine
bore-scoped, at least in the lower cylinders. Wanting a knowledgeable
opinion, I flew the plane to Allen Tinnes and his folks at Lamar,
Colorado. They looked at the metal in the screen with the roughly 5
hours I had on it since last cleaning and said there was definitely
something going on that needed to be traced down.

Compression was low in two cylinders (#5 & #8), with an obvious exhaust
valve leak on both during the compression check. With their comment,
"We need to get to the bottom of this," I decided to have them tear
things apart (ouch!). All nine cylinders off only showed 4 broken
rings. Why would there be 4 broken rings after only 120 hours on a new
engine? Still no sign of what was causing the metal though.

Took off the front accessory case. Metal in there. Drained the oil
tank; more metal in the bottom of that. Finally, took off the oil pump
and found a loose nut in the pump! Where did that nut come from? A
"Friday afternoon special" from the Romanian factory? That mystery will
probably never be answered.

I took pictures of the nut. Other folks took pictures of the gears and
pump. Pictures are posted here:
http://www.i1ci.com/Flying/OilPump.html. Sorry the pictures of the
gears are fuzzy. You can see that the top land's are really worn down.

Sooner or later the pump would have failed. How the nut didn't lodge
between the housing and the drive (?) gear is a mystery (minor miracle
perhaps).

I have about 14 hours on the engine now since replacing the oil pump.
Virtually zero metal is showing now.

Allen Tinnes, at Lamar, Colorado, and his folks did an outstanding job!
I highly recommend them (contact me off list if you want their contact
information). These folks really know the M-14 inside and out (my
engine in particular <grin>).

Ted Waltman
N142SR






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[George Coy]

Ted,
I am glad that you have sorted out the problems. I spoke to Al several
times during the process. I doubt that the nut was in the engine as it came
from the factory. I suspect it got there when the factory mounting ring was
removed to install the Moose motor mount. It is necessary to remove the
magnetos, the oil pump and the fuel pump to change the mounting rings. I do
remember that the gentlemen you bought the airplane from had some difficulty
in this process and we spoke several times on the phone concerning the
process.

For your information the following is the testing sequence for EVERY engine
at the Romanian factory:

1. The engine is assembled and connected on a stand with an electric engine
that rotates the engine. The engine is rotated without sparkplugs by the
electric motor for a period of 4 hours minimum. During the period oil is fed
to the engine and the outlet oil is monitored for metal constant. After the
what ever period it take for there to be NO metal in the outlet oil, the
engine is then prepared and put on a test stand.

2. It is run on the stand for a period of time, usually a few hours, and
then removed and disassembled. The steel parts are magnafluxed and all parts
are checked dimensionally for normal break in.

3. The engine is reassembled and put back on the test stand for the final
run. The test data is taken and recorded in the log book. During all test
stand runs, the oil is monitored for metal content as well.



George Coy
President
Gesoco Industries Inc.
629 Airport Rd.
Swanton, VT 05488
TEL 802-868-5633
FAX 802-868-4465
Web Site www.gesoco.com
e-mail George@gesoco.com
Franklin County Airport (KFSO)

-----Original Message-----
From: mike.davis@dcsol.com [mailto:mike.davis@dcsol.com]On Behalf Of Ted
Waltman
Sent: Tuesday, November 30, 2004 8:16 PM
To: Murphy List
Subject: Engine making metal...the rest of the story


Some time ago, I reported that my M-14P was showing metal in the
Aviation Development Corporation (ADC) oil screen. As I reported, some
folks told me it wasn't any big deal, as these engines are legendary
tough. Another guy told me he wouldn't even taxi it. I talked to folks
all over the country about this, including the ADC folks. This was
supposedly a brand new engine with, at the time, about 120 hours.

Finally I decided that I'd check the compression and have the engine
bore-scoped, at least in the lower cylinders. Wanting a knowledgeable
opinion, I flew the plane to Allen Tinnes and his folks at Lamar,
Colorado. They looked at the metal in the screen with the roughly 5
hours I had on it since last cleaning and said there was definitely
something going on that needed to be traced down.

Compression was low in two cylinders (#5 & #8), with an obvious exhaust
valve leak on both during the compression check. With their comment,
"We need to get to the bottom of this," I decided to have them tear
things apart (ouch!). All nine cylinders off only showed 4 broken
rings. Why would there be 4 broken rings after only 120 hours on a new
engine? Still no sign of what was causing the metal though.

Took off the front accessory case. Metal in there. Drained the oil
tank; more metal in the bottom of that. Finally, took off the oil pump
and found a loose nut in the pump! Where did that nut come from? A
"Friday afternoon special" from the Romanian factory? That mystery will
probably never be answered.

I took pictures of the nut. Other folks took pictures of the gears and
pump. Pictures are posted here:
http://www.i1ci.com/Flying/OilPump.html. Sorry the pictures of the
gears are fuzzy. You can see that the top land's are really worn down.

Sooner or later the pump would have failed. How the nut didn't lodge
between the housing and the drive (?) gear is a mystery (minor miracle
perhaps).

I have about 14 hours on the engine now since replacing the oil pump.
Virtually zero metal is showing now.

Allen Tinnes, at Lamar, Colorado, and his folks did an outstanding job!
I highly recommend them (contact me off list if you want their contact
information). These folks really know the M-14 inside and out (my
engine in particular <grin>).

Ted Waltman
N142SR






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