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Is my engine self-destructing?

j-red

Well Known Member
I love to learn. That's one of the things that got me into the airplane building thing. It's also taught me that there's a lot I have yet to learn...

I have a lycoming o-360, 675 hours SNEW, but was recently rebuilt (by me) in response to a prop strike. Case professionally cleaned, cam and crank polished, tappets overhauled, new bearings, overhauled jugs, new pistons, piston pins, etc. It now has about 75 hours on it since the rebuild. These 75 hours have been accrued over the past 9 months.

The engine uses virtually no oil, and has made good compression (78+/80 at 10 and 50 hours, haven't checked it since), and runs smooth and strong. Oil temps are a little low, but fine and pressure is about 80psi in cruise, 60 at idle.

After the rebuild, I ran the engine for about 10 hours, then replaced the oil and filter. I didn't have the oil analyzed (I said I had lots to learn), but did open up the filter and didn't notice any metal of any kind in it. I didn't wash the filter with mineral spirits or anything, so it could be that i just didn't notice but there was some there. Between 25 & 30 hours later, I drained the oil, but did not replace the filter. I was told that the filter was good for 50 hours, so i thought i'd only replace it every other time. In retrospect, this might be fine later down the road, but was foolish at the very beginning of the run in that the filter could have provided useful information. I did, however, send off a sample of the oil to Blackstone for analysis. Metals were a little high, but that was expected for an engine just breaking in. Fast forward to about 2 weeks ago. 25 hours have passed and it's time for another oil change. This time oil and filter were changed. Oil was sent off, and the filter sat in the bucket waiting for me to get around to checking it. Report came back that iron and aluminum had actually increased slightly, and after only 25 hours instead of 30. Alarmed, I immediately cut open the filter to inspect it, and have lots of miniscule shiny non-ferrous bits in there as well as a couple half-inch long hairlike slivers of ferrous metal. I'd guess there's a shiny speck in almost every pleat, and a few pleats with quite a few. They're embeded in there, so collecting them for a teaspoon reading isn't going to happen... Running a magnet over the filter reveals virtually no iron dust or anything else.

What I don't know is:
Do I have a major problem that has trashed my bearings already, or am I totally flipping out over absolutely nothing?
Is this typical metal wear for a new engine and a filter with 50 hours on it?
One helpful avweb article mentioned flakes of aluminum and hairs of steel pointed to a broken ring. I have a borescope and wonder what I should be looking for in that regard?

The plan right now is to scope the cylinders the next time I'm at the airport, then run for ten more hours before pulling the filter for inspection.

Here is a video that shows the filter, and it really doesn't do it justice. Every little white speck is a shiny piece of metal.
https://youtu.be/2APnb5haYak

And the oil Analysis:
oT1.jpg
 
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I don't see anything alarming in either the oil analysis or the video Jon - you should expect some particles while the engine breaks in, and even the oil analysis says that you should consider a borescope "if you see any unusual temperatures". He mentions the potential for having glazed cyclinders - you'd know this by high oil consumption - what are you seeing for hours/quart?

The particles in the filter coudl be there from anytim,e since hour 11 (if I understand your post), and there really isn't very much there - nothing that would trigger my alarm bells if I was flying behind the engine.

Paul
 
What you are seeing is perfectly normal for a new/newly-rebuilt engine. Don't fret over it at all.

Vic
 
If you squeeze the oil out of the element aggressively in a vice you will find (see) much more than if you just let it drain. It appears you may have done just that as the element looks dry.
Looks good but to be safe check it again in 25 hrs and watch for declining metals in the analysis.
Tim Andres
 
Thanks for the input guys. Makes me feel much better as I learn more about what is common/normal and not.
 
I'm guessing you use an additive based on elements such as phosphorus.
Also I would say your air filter may be dirty based on the amount of silicone.
 
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If you squeeze the oil out of the element aggressively in a vice you will find (see) much more than if you just let it drain. It appears you may have done just that as the element looks dry.
Looks good but to be safe check it again in 25 hrs and watch for declining metals in the analysis.
Tim Andres

Tim, as an alternative, you can take the pleats and sit on a bed of 1/2" of paper towels then spritz mineral spirits over the top and it will pull all the oil out of the filter paper and not disturb the accumulated surface material. A bar of steel ( a clean weight) to add better contact pressure with the towel bed helps wicking. It will get quite dry after about an hour. This was SOP in my former engine lab for filter inspection.
 
Thanks Bill for both comments.
I?ve been watching elevated copper levels on mine since overhaul, especially with the Lycoming rod bushing fiasco (which I missed due to overhaul date) Then I realized I used ?copper coat? gasket sealer on some of the gaskets when I assembled it. While I?m not certain that product is behind the elevated number, I?m pretty sure I?ll see it drop over time. And I think that is the real value of these reports, establishing a base line and watching trends.
If RTV was used anywhere (hopefully very little or none), that will also cause high silicon numbers. I had not considered the silicon gaskets causing it.
Tim Andres
 
I fly almost exclusively off of grass. Do you think that would contribute to intake dirt/sand and be seen as silicon in the oil? Filter was sealed up pretty well during the install, but I'm intending to pull it at annual in a month or so and give it a good cleaning and re-seal.
 
I can?t say for sure, but what you should do in any case is remove the air cleaner and wipe the intake plumbing/system down stream of the filter with a clean white rag and see if there is any dirt on it. Should be clean.
Tim Andres
 
Might be a silly question, but when you take the dipstick out do you wipe it on a rag or on the ground? Have heard in the past of high silicon being caused by this.
 
I don?t take the dipstick out completely, just enough to read it and put it back in. I always check it cold, so no real reason to wipe it with anything. Only time it comes all the way out is oil change time and then it is rested on a soft cloth on the wing.
 
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