Anyone have a theory or knowledge as to what can cause a wrist pin button to start abrading on the cylinder wall?
Lycoming cyl. assemblies with aluminum buttons on the wrist pins and on #1 cyl. I have very light evidence of rubbing
and some aluminum in the filter with 480hrs.smoh on IO320L.
I've run Lycomings for a long time and never had anything like this. Looking for ideas.
Steen

Steen, wish I could help - but haven't seen this before.

We just discussed that at the Comanche Pilots Service Clinic in Rockford last weekend.
For more detailed info on why the wrist pin plug abrades, contact Dave Allen at Poplar Grove, 800-397-8181. He's quite familiar with that condition.

George

What a small world!! Poplar Grove is my home airport up north and they have overhauled several engines for me (Poplar Grove Airmotive has an excellent engine overhaul facility with a
good reputation).
I'll talk to Dave.
Thanks.
Steen

Steen, when you find out - would you kindly post so we can all learn - especially if there is something we can watch for or do differently that can prevent it or find it early. thanks.

Will do, Pat.
In Rogers, Ar. now but will be back at north home next week and will talk to Dave and let you all know what I find out.
Steen

Steen - again small world - have been going to KROG since 1975 when there was only a phone booth and old farm house at the south end and all the permutations in between. Landed behind 1WM once and yes, Sam was flying. Folks are real nice there.

The good news about Walmart moving their fleet from Bentonville to KROG was the ILS they were able to get vs the DME arc approach, the bad news is it is much more of a corporate airport now and we little ones are relegated to just a very few and far away tie downs - but they drive us to and from.

Hope your experience is just as pleasant as ours have always been.

Steen:

A year (1991) after I bought my Comanche 250 I really began sucking up the oil. Went from a quart every 4 hours, to a quart every two. One day after doing an oil change I brought home the filter and cut it open with my new oil filter cutter. Low and behold when I opened the filter up, I scrapped out enough aluminum to cover about half the palm of my hand. Took the airplane to my mechanic and we started to pull cylinders. Finally when we got to the last one we saw not only a broken ring, but that the wrist pin plug had wobbled a hole about half the size of a dime in the piston. Since I was new to the whole airplane ownership and didn't have the money for a complete overhaul I elected to top all the cylinders. That was on an engine that had about 700 SMOH.

My engine now has about 1900 hours and I've had to change out a few cylinders along the journey. As to what cause a broken oil ring or worse a wrist pin to start to eat itself, I don't know. Maybe pulling the prop through a dozen times on preflight might help. Still nursing my engine for another couple of hundred hours before I go the Reman route. Hopefully Lycoming would have an answer or someone in the the group.

Alan

Thanks, Alan. Sounds like you, by proactive approach, averted a major engine failure.
My IO-320 runs great and uses a qt. every 12-15 hrs....I put in eight qts. with a new filter at change time and run it 30-35hrs. to the next change and it never gets down to
5 qts. so I never add any. But I have something going on with a wrist pin button. Going back north in the next couple of days and will check with Poplar Grove Airmotive soon.
I also have the annual starting next Monday and we will do some deeper probing at that time. I'll let you-all know what I find.
Steen

First of all, Pat, I gotta know. Was Sam flying the AeroCommander or was he still flying the original Walmart Corp. plane....an Ercoupe?
Got north, finished the annual and found the oil filter clean.....no aluminum. No further marks on the cylinder walls, compressions all 78/80.
On returning to Poplar Grove.....home up north....C77....I talked to Dave Mitok....Dave Allen not around...but Mitok runs the engine overhaul facility (Poplar Grove
Airmotive) and is very knowledgable re engines. He not only told me what the cause is but showed me pictures of several engines that had the problem big time.
In a nutshell, fly your bird often if it has nitrited steel cylinders (chrome does not have the problem) to prevent rust from forming on the cylinder walls. The rust abrades the
aluminum wrist pin button and causes fine slivers of aluminum to show up in the filter.
I was laid up and on crutches for 4 mos. from late winter to summer and the bird sat without running for that time. A fine coat of rust formed and I probably shaved the aluminum
the first few minutes of running as the rust got wiped off the cylinder walls, then the problem went away. I was lucky and will need to keep a close watch on the filter. If I get
more aluminum, the fix is to remove the cylinder and hone it carefully and replace....new rings may or may not be called for.
All steel cylindered Lycomings can have it happen, but the O-235 is particularly prone.
Steen

Hey Steen,

Thanks for the wrist pin description. Interesting - guess we're lucky with our 'toy' 320 engines. It sat during elder care and had to play with the right cam shaft only at overhaul due to apparently some rust damage.

WRT Sam - if I recall correctly, it was a Seneca. The Ercoupe hanging in Beaver Lake Aviation is similar but not actually Sam's.

Bear with me as I share another fun KROG story. It was 1988 - before tower, before big FBO building, before KXNA so no radar coverage. Mom had loaned us the twin when she still lived in Chicago to us in Texas so we could fly to KROG nearly every weekend as Ken's Mom was dying of colon cancer. We were working on buying a plane but hadn't done it yet.

One Friday, we headed up after work as fast as we could because storms were moving into KROG. No ASOS. We knew a Walmart plane was landing ahead of us because we'd been on the same frequency. It was well after sunset. The kind pilots in that plane landed and made the following kosher announcement, "123WM has landed on dry pavement at Rogers on 01. The lightning to the northwest of the runway did not hit us." We kept our speed up and we landed safely on 01and just as we started our turn off the runway at midfield, the downpour began. We called Ken's Dad to pick us up as usual and he said to call my Mom. She'd been watching the weather, of course and was glad we had landed without incident. Before Flightaware.com and cell phones, Mom was still watching out for us from 800 miles away - even at then age 38, it was nice to be so loved. Wonderful thoughtful pilots, great mother, fabulous memories.

Pat,
Thanks for sharing those memories.
A couple years ago, my wife and I were returning to KROG from an airport near Austin, Tx. and racing a front rapidly approaching from the west. I had an out all the way.....just turn east and all was clear......
but, of course, Krog was our goal. We made it in with maybe 10 minutes or less to spare before the storm front hit. Driving to our home in a pouring rain the cel phone rang and it was our younger son letting us know that
in his estimation we had cut it too close and he was worried as he watched our real-time progress with the weather depiction on his computer and was very much with us in the cockpit in a loving way.
Generational love works both ways. Ain't it grand!!
Steen

Yes, it is - great story on your son ... Dad, you should listen up

All,
If you haven't seen it, there is a great article in this month's Light Plane Maintainance about metal in the oil filter. The author describes in about 3 pages all the different types of metal you might find in your oil and filter and the most likely places it would come from. He even divides some of the metal types into different groups based on the shape and size of the particles. Hope it helps.

Jim