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  #1  
Old 05-19-2015, 05:15 AM
N208ET N208ET is offline
 
Join Date: May 2007
Location: St. Helens OR
Posts: 429
Default Lycoming Piston Pin Plug Failure

http://imageshack.us/a/img538/8093/DVYSbA.jpg[/IMG]http://imageshack.us/a/img537/2203/cEBvKg.jpg[/IMG]
Anybody see anything like this happen before? It had the bronze plug installed which wore itself to pieces, taking out the piston with it. Cylinders are chrome, heck it might be serviceable still. The engine however had to come off for complete tear down. Metal was in the bearings and throughout the case. The sump was full of metal specs. Total Buzzkill!
This is a Lycoming 0-360 narrow deck engine. EMag, Catto Prop, and have used auto gas the last 150 hours or so. TT 500 hrs on lower end, 700 hours on cylinders.

Randy
8A

Last edited by N208ET : 05-19-2015 at 06:16 AM. Reason: Pic fix
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  #2  
Old 05-19-2015, 05:39 AM
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catmandu catmandu is offline
 
Join Date: Dec 2005
Posts: 917
Default

That is some ugliness for sure. On the IO360-C1C on our Arrow, with 500 since a top, we had some metal show up in the oil filter and oil analysis.

Thought at first the excessive wear on some of our pin caps was the source:



But, when the last cylinder was pulled, a failed ring and chunk of piston was probably the culprit:



Luckily we had an overhaul fund, so the decision to do the right thing was pretty easy.
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Last edited by catmandu : 05-19-2015 at 06:43 AM. Reason: Randy got the pics to work, below
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  #3  
Old 05-19-2015, 05:56 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 5,516
Default Broken Ring

It looks like it started with a broken ring. Without seeing the top of the piston it is impossible to tell if that was caused by detonation or from the initial build process.

Are you checking cylinder leak down annually and oil filter inspection for metal on each oil change? That ring has been broken for a long time. Hundreds of hours, not tens of hours.

Edit: Shaving off the pin end button is typical. Usually, it is due to it passing over a step in the cylinder bore caused by the ring travel area. Conti uses a piston ring at the bottom of the piston so that the button won't pass by the step from ring wear! A twisted, but effective design, solution. Usually, it just shows up as metal in the screen and filter. It is identified by the sliver shape of the metal pieces. They also have aluminum buttons (lighter). The button was NOT root cause.
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Last edited by BillL : 05-19-2015 at 06:03 AM.
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  #4  
Old 05-19-2015, 06:22 AM
N208ET N208ET is offline
 
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Location: St. Helens OR
Posts: 429
Default More pics






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  #5  
Old 05-19-2015, 06:38 AM
Robert Anglin Robert Anglin is offline
 
Join Date: Mar 2008
Location: houston, texas
Posts: 900
Default 2 Cents

If this were mine. I would not use that Rod again. I would exchange it for one you knew was good and had the rest-pin bushing boarded strait and reamed very nice. Just me and my picky ways. Yours R.E.A. III #80888
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  #6  
Old 05-19-2015, 06:40 AM
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catmandu catmandu is offline
 
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Posts: 917
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Bill, just to clarify, those pics I posted were from the Arrow, not Randy's RV. We did a leak down test every 100 hours, nothing notable.
Oil analysis and filter check every oil change. We had a spike in the analysis with no metal found on one oil change, then a continued spike
with fine particles in the filter on the subsequent oil change. That led to the pulling of cylinders, and eventual overhaul.

Sorry for the threadjack, Randy.
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Last edited by catmandu : 05-19-2015 at 06:44 AM.
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  #7  
Old 05-19-2015, 07:36 AM
David-aviator David-aviator is offline
 
Join Date: Feb 2005
Location: Chesterfield, Missouri
Posts: 4,514
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Quote:
Originally Posted by N208ET View Post
http://imageshack.us/a/img538/8093/DVYSbA.jpg[/IMG]http://imageshack.us/a/img537/2203/cEBvKg.jpg[/IMG]
Anybody see anything like this happen before? It had the bronze plug installed which wore itself to pieces, taking out the piston with it. Cylinders are chrome, heck it might be serviceable still. The engine however had to come off for complete tear down. Metal was in the bearings and throughout the case. The sump was full of metal specs. Total Buzzkill!
This is a Lycoming 0-360 narrow deck engine. EMag, Catto Prop, and have used auto gas the last 150 hours or so. TT 500 hrs on lower end, 700 hours on cylinders.

Randy
8A
YES!

Was flying with a friend in a Tri Pacer a few years back, he flew me to and from Jeff City, MO for a RV-6 check out.

On the way home, the engine did not seem to be producing the same power as earlier that day. We made a precautionary landing at Herman, MO checked things over visually and found nothing amiss. Cranked up, good mag check, and continued on to Spirit.

Next day the same thing was found, the wrist pin retainer had failed and the pin was destroying the cylinder - big time.

It is a credit to the toughness of a Lycoming engine. We made it home.
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  #8  
Old 05-19-2015, 09:28 AM
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bret bret is offline
 
Join Date: Feb 2010
Location: Gardnerville Nv.
Posts: 2,828
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It looks like detonation erosion on the piston crown edge, did the compression rings have any tension left in them, looks like they were not sealing for a long time, only takes a small amt of oil ontop the piston to precurse detonation......those are some scary pics!
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  #9  
Old 05-19-2015, 10:10 AM
Richard@Langair Richard@Langair is offline
 
Join Date: Mar 2010
Location: Scappoose
Posts: 119
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Oh NO Randy!! That is not fun at all!! Sorry to see the damage there.

What made you tear it down? Was it a sudden symptom or gradual?



Richard from Duckworks and Langaire
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  #10  
Old 05-19-2015, 11:06 AM
jpowell13 jpowell13 is offline
 
Join Date: Nov 2008
Location: Baton Rouge, LA
Posts: 671
Default Chromed cylinders

I also have chromed cylinders. Was wondering if chrome lining wears out rings faster than standard cylinders? John
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