Whaddya think of this valve?

Jim K

Jim K

Final Approach
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It's definitely turning as it's in a different position than it was when I took its picture 25 hours ago. Compression is 78/80. It looks exactly like it did 25 hours ago, and they were pretty hard, hot hours. All 5 other exhaust valves are completely concentric. My mechanic isn't worried about it, but he doesn't do much boreoscopy.
20220628_105921.jpg
20220628_105712.jpg

Here it is about 100 hours ago
220610_124431.jpg

I'm probably overthinking it. I'd feel better though if it was concentric.

Lap it?
Monitor it?
Stop worrying about it?
 
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I would not be concerned, exhaust valves rotate about a full revolution each minute during typical cruise power settings to ensure heat is evenly distributed. Based on the pictures, it only appears to be just a little non-concentric, so I don’t see anything alarming here, especially with a satisfactory compression reading that you mentioned.
 
That valve is only very slightly non-concentric and being a Lycoming, is not nearly as susceptible to valve burning as a Continental (due to the sodium filled valves that carry the heat up the stem and away from the face ... though this has the tradeoff that they are more susceptible to sticking due to oil carbonizing on the stem/in the guide). Lapping would generally only be indicated if there was a substantial leak past the exhaust valve. I'd concur with your mechanic.
 
EdFred said:
You should probably sell the plane at a steep discount. I can write you a check this weekend.
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I'll sell it to you for what I have in it...:confused:
 
Dave Theisen said:
Better grab it now @EdFred , you won’t be able to afford if after he takes a few more family vacations in it. :)
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The valve is concentric, the camera is off to the side. The seat looks normal too. Compression tests are solid evidence of proper function. The main exception is valves that stick open occasionally.

Fly it, there is nothing wrong there.
 
Those clean cylinder heads look like lean of peak ops to me. Mine look medieval, lol.
 
455 Bravo Uniform said:
Those clean cylinder heads look like lean of peak ops to me. Mine look medieval, lol.
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Haha she doesn't like LOP, but I generally run 65% power and real close to peak egt. Keeps the plugs nice & clean, and seems to be the most efficient cruise setting. LOP gives up too much speed, and running ROP at 75% burns too much more gas for the extra speed

Thank you everyone (except @eman1200) for your constructive comments. I'll finally be able to stop staying up nights worrying about my #3 cylinder.

Of course I'll still be borescoping it every time I have the cowl off....
 
Jim K said:
Haha she doesn't like LOP, but I generally run 65% power and real close to peak egt. Keeps the plugs nice & clean, and seems to be the most efficient cruise setting. LOP gives up too much speed, and running ROP at 75% burns too much more gas for the extra speed

Thank you everyone (except @eman1200) for your constructive comments. I'll finally be able to stop staying up nights worrying about my #3 cylinder.

Of course I'll still be borescoping it every time I have the cowl off....
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that’s what happens when one buys those tools, they just need to be used.
 
Do you have an engine monitor? If you are worried about #3, keep a trend/eye on cylinder and exhaust temps.
 
Looks bent to me.

Either that, or the angle just shows it is slightly open and not viewed from the top.
 
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