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what am i seeing on this piston?

P

prkaye

Well Known Member
I had another look inside one of my cylinders with the new Ablescope today. One the piston, i see these two little raised thingies (I don't know how else to describe it)... see the picture below. What am i seeing here?

Here's another look at another part of the same piston... is it normal for piston faces to have so much crud on them?
 
Deposits on piston

Yes it's carbon and or lead byproducts. It's normal to see this.
If CHT/ EGT looks normal, no action is required.

Good luck
 
I'm doing my condition inspection currently. Borescoped my cylinders yesterday. They always look like the craters of the moon!
I can't wait for unleaded avgas.

Piston at 1071 hours:
i-wBtJWRc-M.jpg


Big old lead deposit on the #1 lower spark plug:
i-rzVn88d-M.jpg
 
May be my imagination . . . .

That first picture looks like two pieces of piston ring sticking out through the top land. Just odd looking, not like any carbon I have ever seen. Using the ablescope, insert a magnet to in the other plug hole and test the unknown debris.

If it is a broken ring protruding, leak down would be poor, there could be worn area vertically on that side of the cylinder-different from the other clocking, and if that is present . . . then oil consumption could be higher from the cylinder wall damage.

Hope this is not it.
 
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I did compression test today and all cylinders were about 76/80. Pistons and rings are all new with only 22 hours on them since Iran by aerosport. Oil consumption seems to be 12hrs/qt or better.
 
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BillL said:
That first picture looks like two pieces of piston ring sticking out through the top land. Just odd looking, not like any carbon I have ever seen. Using the ablescope, insert a magnet to in the other plug hole and test the unknown debris.

If it is a broken ring protruding, leak down would be poor, there could be worn area vertically on that side of the cylinder-different from the other clocking, and if that is present . . . then oil consumption could be higher from the cylinder wall damage.

Hope this is not it.
Click to expand...

+1

Definately looks like two items protruding through the piston top in ring land area. In my experience carbon doesn't form like that. hard to imagine rings bending that much vs breaking, but sure looks like something like that. A very odd looking pic of a piston top. The alum above the land is relatively thick, so struggle to see a ring breaking through it as opposed to cracking it.You can also see a pool of liquid oil that appears to be originating from the protrusion, but that could be a reflection artifact. I also wonder if something broke off of something else or was injested and the force allowed it to dig into the soft piston top. I would definitely take more pics of that area for analysis.

While I can't identify what those two things are. I can say it IS NOT "perfectly normal."
 
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Definately looks like two items protruding through the piston top in ring land area.
Click to expand...
This hypothesis spooked me, so i came back out to the airport, took the top cowl and top plugs off and spent about 30 minutes hunting with the borescope. I could not locate those protrusions that i saw yesterday. I had run the engine yesterday after taking those images. But after carefully hunting around the perimeter of the piston, from many angles and positions in teh stroke, i could not find these protrusions i saw yesterday. Hopefully that's good news.
 
prkaye said:
This hypothesis spooked me, so i came back out to the airport, took the top cowl and top plugs off and spent about 30 minutes hunting with the borescope. I could not locate those protrusions that i saw yesterday. I had run the engine yesterday after taking those images. But after carefully hunting around the perimeter of the piston, from many angles and positions in teh stroke, i could not find these protrusions i saw yesterday. Hopefully that's good news.
Click to expand...

I wouldn't worry about it then. But I would go back to the original pic and zoom in for more clarity; I was unable to with your pic. Definitely possible this is nothing more than more reflections.
 
Time to put aside the paranoia and go enjoy your new engine!
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Fair enough! A 35k CAD IRAN sort of inspires paranoia! I'm beginning to think that buying this borescope has already caused me way too much stress... I am going hunting for problems... it's my personality I guess!
 
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