Superior Millenium Cylinder Issue and Resolution (Washboarding cylinder walls)

[Shrike]

Posting this here because I spent some time investigating an issue and want to share the the issue and information. A little over a year ago I replaced all four cylinders with Millenium's on my RV7A with an O-360. Flew 25 hours and did an oil change and oil analysis. Oil analysis came back with elevated wear metals which is to be expected and they were not crazy high just what I would expect after a top over haul. Flew for another 50 hours and did another oil change, oil analysis and borescope. Wear metals were at about the same level as they were with the 25 hour oil change so in my mind that is half the wear metals since it is twice the flight time. The bore scope showed some odd wear on one the cylinders (See attached). I was a little concerned but thought the wait and see approach was the best course of action. Just did another 50 hour oil change, oil analysis and borescope. Bore scope showed very visible washboarding on the top of three cylinder walls running the full stroke. The oil analysis came back with increased wear metals. Compression tests were all 78/80 and the engine was running perfect with no signs of issues and no anomalous reading on the engine monitor. Oil consumption was 5 qts the first 75 hours and 3 qts the last 50 hrs so nothing excessive.

I called Superior and talked to Bill Ross. Bill told me Superior had issues with this "washboarding" off and on and chased the problem for some time before figuring out that the face of some compression rings were not correct from their supplier. Superior started shipping Millenium cylinders with Lycoming rings for a quick fix and now have a new supplier and are back to shipping cylinders with Superior rings.

The Resolution:
At no charge, Superior has shipped new cylinders, return labels to ship the old cylinders back and said they will also cover the labor for R&R. I could not be happier with the resolution to this issue. Superior stood behind their product, admitted a mistake and made it right. While I do not like my plane down for a bit over a week getting this resolved, this is the best resolution that could have come from this. A company that admits a mistake and makes it right!!! Who knew that happened anymore.

Photo 1 Borescope at 75hrs
Photos 2 Brorescope at 125hrs
Photo 3 Wear on #4 really starting to accelerate at 125hrs

If you have replacement Millenium cylinders installed within the last few years get a borescope done if you have not had one. I can't preach enough on regular oil analysis and borescopes with every oil change. I would have never know about this issue until I started using more oil and losing compression.

 

[lr172]

Posting this here because I spent some time investigating an issue and want to share the the issue and information. A little over a year ago I replaced all four cylinders with Millenium's on my RV7A with an O-360. Flew 25 hours and did an oil change and oil analysis. Oil analysis came back with elevated wear metals which is to be expected and they were not crazy high just what I would expect after a top over haul. Flew for another 50 hours and did another oil change, oil analysis and borescope. Wear metals were at about the same level as they were with the 25 hour oil change so in my mind that is half the wear metals since it is twice the flight time. The bore scope showed some odd wear on one the cylinders (See attached). I was a little concerned but thought the wait and see approach was the best course of action. Just did another 50 hour oil change, oil analysis and borescope. Bore scope showed very visible washboarding on the top of three cylinder walls running the full stroke. The oil analysis came back with increased wear metals. Compression tests were all 78/80 and the engine was running perfect with no signs of issues and no anomalous reading on the engine monitor. Oil consumption was 5 qts the first 75 hours and 3 qts the last 50 hrs so nothing excessive.

I called Superior and talked to Bill Ross. Bill told me Superior had issues with this "washboarding" off and on and chased the problem for some time before figuring out that the face of some compression rings were not correct from their supplier. Superior started shipping Millenium cylinders with Lycoming rings for a quick fix and now have a new supplier and are back to shipping cylinders with Superior rings.

The Resolution:
At no charge, Superior has shipped new cylinders, return labels to ship the old cylinders back and said they will also cover the labor for R&R. I could not be happier with the resolution to this issue. Superior stood behind their product, admitted a mistake and made it right. While I do not like my plane down for a bit over a week getting this resolved, this is the best resolution that could have come from this. A company that admits a mistake and makes it right!!! Who knew that happened anymore.

Photo 1 Borescope at 75hrs
Photos 2 Brorescope at 125hrs
Photo 3 Wear on #4 really starting to accelerate at 125hrs

If you have replacement Millenium cylinders installed within the last few years get a borescope done if you have not had one. I can't preach enough on regular oil analysis and borescopes with every oil change. I would have never know about this issue until I started using more oil and losing compression.

Just went through this on a 360 i tore apart. Major pita. They offered new cylinders but would have to do all 4 as they were 10 over and lyc no longer sells 1 0 over rings and i was unwilling to use the superior rings. They did agree to nuy me conti rings and pay the shop for the honing.

 

[Quotafiller]

nice write up. good on the company for making it right

 

[IO390]

I don’t have the same level of sympathy. Whilst it seems good that Superior are happy to replace faulty products, there have been so many reports of this excessive wear/washboarding on Superior cylinders that it’s beyond a joke.

To me, they are selling cheap crap and just replacing failed items instead of improving their initial quality.

Superior farm out all of their manufacturing and their quality control seems lacking. It makes a mockery of the PMA system. “Aircraft grade” - yeah right…

 

[Metzger130]

I bought my airplane and it has just had 4 cylinders replaced. First CI a year after and I had wash boarding on 2 cylinders. Superior replaced under warranty but didn’t cover my labor. This year I have excessive oil consumption, guess I need to borescope again and see what it looks like. Maybe I’m in the boat you are for the ring issue. like IO390 said, I’d hate to be replacing cylinders AGAIN.

 

[tthrew]

I had the same experience as Shrike with the O-360 Superior Cylinder kits. I did an OH at 1500 Hobbs because of lifter spalling and I used new Superior cylinder kits. My washboarding showed up in 5 hours using a borescope. The resolution was the same - new kits with Lycoming rings. I also dealt with Bill Ross. It is unfortunate Superior had a supplier issue but Bill was very responsive and did a good job on customer service with me. I have about 90 hrs on these cylinders now, have borescoped them 3 times, so far so good.

 

[DanH]

We found two bad sets here at 08A, on two certified airplanes with low time Superior top ends. Superior replaced both cylinder sets and and paid the labor bill. We may find more, but no one here is worried. Superior is doing the right thing.

 

[walkman]

Pity they didn't "do the right thing" with crankshaft issues

 

[mike_tailwind]

I've had the same issue and posted on it in another thread here. No washboarding, but excessive wear and scuffing as in the OP's first picture. They replaced one cylinder at 112hrs that had compression down to 60/80, but did not replace the others. The new cylinder shows the same excessive wear. I showed them images after 25 hrs and they said they could still see crosshatching (I couldn't). I just completed a condition inspection at 160hrs. Compressions are all around 72-74/80. The metals are still elevated. Iron is coming down but chromium is still high, and I can find some ferrous metal in the oil filter. Maybe it is time to contact them again.