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  #11  
Old 11-01-2012, 10:37 AM
rvator10 rvator10 is offline
 
Join Date: Apr 2006
Location: Fountain Hills, arizona
Posts: 117
Exclamation MCD

I have been in the turbine Auxiliary Power Unit (APU) overhaul world for 24 years, I completely agree, it?s time to take this engine apart before failure and emergency landing, don?t take the risk! That level of metal is not good.
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  #12  
Old 11-01-2012, 11:57 AM
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JonJay JonJay is offline
 
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Location: Battleground
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I would not disagree or argue with any of the previous comments. However, I had a similar amount of metal in my 0320 Bucker a few years ago and it caused obvious concern. I also received a host of opinions similar to what you had received before you posted.

We decided, right or wrong, due to the high engine time and impending rebuild, to let it go and recheck at 10 hours. There was less metal. We checked again at 25. Less metal still. Subsequent oil changes showed little to no metal and it has been that way ever since.

My circumstances may be very different than yours, so please, accept this as only another data point to consider. My engine was/is high time, over 2300 hours today since new, never been topped. It was only ran about 10 hours a year for many years, but it ran regularily.

I liked to take advantage of the inverted systems in the Bucker. The prior owner did very little upside down stuff and no negative g's. We think my more agressive flying dredged up years of accumulated "stuff" in the sump. Some of that stuff was metal that had accumulated through normal wear.
I have no proof of this theory, but my engine has been happily running along with good power for many happy years since I found that initial metal.
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  #13  
Old 11-01-2012, 01:23 PM
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airguy airguy is offline
 
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Location: Garden City, Tx
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If his style of flying has not changed appreciably recently (dredging up sludge as alluded to above), then if it were my engine the only additional flying time it would make would be to get it to the location where the teardown would take place.
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  #14  
Old 11-01-2012, 02:43 PM
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JonJay JonJay is offline
 
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Did you pull the screen?
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RV1 - Proud Pilot.
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  #15  
Old 11-01-2012, 02:54 PM
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rocketbob rocketbob is offline
 
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Its one thing if you see aluminum or bronze in filter, its another to see steel. When you see steel only other steel components cause the wear and that will get my attention.
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  #16  
Old 11-01-2012, 03:33 PM
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Kwright Kwright is offline
 
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Location: Roy, UT
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Default Pull the screen

I did pull the screen, no debris of any kind was seen.
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  #17  
Old 11-01-2012, 05:01 PM
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AlexPeterson AlexPeterson is offline
 
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Location: Maple Grove, MN
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My experience last year is only one data point, but it was an attention getter. Steel shards in the filter, no real visible problems with cam. All previous filter inspections (1280 hours) showed little or nothing. Same pro/con advice as on this thread. We did a tear down, and found the crankshaft gear not far from failing (which would mean a sudden quietness at some point). Nothing in sump screen.

I'd tear it down.
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  #18  
Old 11-01-2012, 09:57 PM
Bob Axsom Bob Axsom is offline
 
Join Date: Mar 2005
Posts: 5,685
Default You are very good about keeping up with your thread

I am very impressed with your attention to your thread and providing timely feedback to poster's questions. I just went to the Lycoming school within the past couple of weeks so I feel like I know something but I know I should keep my fingers off of the keyboard because it is classroom knowledge not real work experience. OK all of the poor little me talk aside, you know the engine hasn't been used but on the average of around 17 hours a year and Joe Doebler our Lycoming instructor hammered it into us that the biggest problem with their engine is lack of regular use and the resulting rust. The sloped cam lobes and the convex cam follower surface are designed to work with each other but the rust on these surfaces can lead to wear on the high edge of the cam lobes and spalling of the cam follower surface, which is the bad thing I think the experts are concerned about but for sure the rust is going to get knocked off into the oil and sump. There is no possibility that the contaminated oil will not get into the filter. Lycoming has a failure criterion for this condition which has not been met and your local "in the business" people have said go ten more hours and check it again. My question is why would you not use it and see if it is a temporary condition due to lack of use or the dreaded failure mode? Or, why would you automatically jump to the worst case scenario? It makes me remember why we decided to build our own airplane for retirement.

Bob Axsom

Last edited by Bob Axsom : 11-01-2012 at 10:10 PM.
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  #19  
Old 11-01-2012, 11:49 PM
Norman CYYJ Norman CYYJ is offline
 
Join Date: Feb 2005
Location: Victoria B.C.
Posts: 1,266
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Steel showing up in the filter! It's your *** in the pilots seat and maybe your loved one or best friend with you.
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  #20  
Old 11-02-2012, 09:00 AM
Bob Axsom Bob Axsom is offline
 
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Posts: 5,685
Default Yes

Exactly!

Bob Axsom
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