Millennium cylinder wall "washboarding"

bluerooster said:
As I suspected. The washboard extends below the travel of the rings. It was bad machining when built. Possibly a dull bit chattering, as it was cutting the bore. It's just more visible with the cross hatch polished where the rings travel.
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It didn’t look to me like the pattern extended beyond the ring travel.

Stroke + (distance between top of top ring and bottom of bottom ring) = pattern length.

<edit: now I think I see what you’re talking about on the untouched cross-hatch. Optical illusion or imagination? Whatever it is, mfg is taking it so that says a lot.>
 
Thought for you. 1) Millennium indicated they had others with this problem, said it was bad machining, and sent replacements.

2) Don’t know why a rash of folks at the same time all improperly broke in their millennium cylinders.
 
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ColinD said:
One thing I can promise is that I didn't perform a lot of prolonged low power descents in a biplane that glides like a greased anvil and rarely climbs above 1500 AGL. :rofl:
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Hi Colin,

I just had a similar problem with my o-320 superior cylinder. It was installed during overhaul 42months ago. It has around 250h in it. I don’t know what to think…. Really bad situation here. Ring broke and pieces fell off it everywhere.
Can you help me out and indicate someone to talk to at superior? I’d really appreciate. Thanks man.
 
Cmtelobo said:
Hi Colin,

I just had a similar problem with my o-320 superior cylinder. It was installed during overhaul 42months ago. It has around 250h in it. I don’t know what to think…. Really bad situation here. Ring broke and pieces fell off it everywhere.
Can you help me out and indicate someone to talk to at superior? I’d really appreciate. Thanks man.
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Which ring? 42 months is just outside their 37 month warranty, but suspect they'll make good. Presume you have all four new at overhaul - see how their blow by is as well (or have your mechanic do it).

Call Superior and ask for Bill Ross in tech support. He is very knowledgeable and helpful.
 
Bill Ross is who I spoke to. He was helpful and, like I said earlier in this thread, it didn't seem like this was an unknown issue to them. I bet they'll take care of your issue, @Cmtelobo

I only have about 10 hours on the two new cylinders on my plane now, and it's too cold to continue flying it. I butchered a leaky tach drive oil seal while trying to remove it a week ago and blew my chance to put more time on the engine during this week's warm spell. I'll update this thread in the spring.
 
Following up on my experience, replaced all six cylinders on a big bore Continental last month following issues with previous set at a little under 700 hours and 35 months TIS. Mineral oil -> 20 hours (one change), then Phillips X/C for 25 hours. Essentially zero oil burn since about eight hours, and Phillips was still golden and no burn when it was changed after 25 hours. So can report that the new cylinders broke in well and seem stable. No compression test; that will be at annual though may peak at valves if plugs have to be done before then.
 
Update on this issue: Of the two cylinders replaced under warranty, one began to exhibit the same washboard wear pattern with less than 15 hours of break-in time. The other appeared to be breaking in normally. I installed Lycoming cylinders and sent the two Millennium cylinders back to Superior. I requested a refund for both (parts only, no labor,) told them I had lost faith in their product and didn't want to waste any more of my time with replacement cylinders. They issued a refund.

I spoke with their rep Teresa Ballard, who told me they now believe the unusual wear is linked to a chrome layer on the rings included with new cylinder kits. She said they haven't had reports of unusual wear on reworked cylinders using Superior rings, and also told me they "deconstructed" cylinders and couldn't find any metallurgical fault.

Glad it's not my problem anymore.
 
Sort of glad they don't make cylinders for dads io 540 so neither one of us try to tempt fate. He currently has channel chrome cylinders.
 
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