And the hours you have on them?

Sent my orig 2100-hr-since-new Lyc jugs to ECI for overhaul and nickel-carbide treatment on the original cylinders (IO-360-A). Developed a crack in the crankcase 44 hours after O/H, so I had the opportunity to thoroughly inspect all the parts. The pistons/rings/cylinders looked perfect, including the skirts. Now have 370 hours on the O/H and oil consumption is ~10-12 hrs/qt, and has been steady since break-in. Compressions are 76-78 and have not varied. Sure hope I get 2000 hrs out of these things, although at the rate I'm going that will be another 15 years.
Also been using Phillips XC 20-50 since the O/H as recommended by ECI, although I have no idea if that will help or hinder ultimate hours.

I have 500 hours on group A cylinders. Engine was built in 2004 and has 10 to 1 compression. No problems at this point. I had to pull one cylinder that showed on and off low compression leaking through the exhaust valve. Turned out to be a bad valve seat when they were cut for higher flow by lycon when new. Penn Yan looked over the rest of the cylinder and found everything to be in great shape. Everyone I have discussed the group A cylinders with says to run them to TBO that there have been no failures beyond the norm with those cylinders. Mine are nickel carbide. Cerminal is a different process from the nickel carbide cylinders. I am told that the nickel carbide cylinders in addition to easy break in have shown virtually no rust even in engines with long down times.

George

260 Hrs on the Hobbs.

More Information if you don't mind. . .
 

Paul,
I have no information to your specific question, however to your engine . . Specific engine conditions affect the results - so what is your compression ratio, do you use timing advance (electronic Ignition or std mags) and does your engine have piston oil cooling jets.

You slipped in new information about the internal conditions - like scuffed pistons, so what about the ring gaps, were they grown substantially? Was there material transfer on the faces of the rings? Or was material missing from the ring - bore contact areas? Was the top land of the piston showing any mild signs of detonation? All of these things indicate how YOUR engine is running and what might have led to the shortened life, other than the bore material itself. For now, let's leave out oil discussions as it is assumed you had frequent oil changes and that wear metals were not showing in your oil analysis, and that additive packages (TBN) were still working well.

Do you run at LOP or ROP in typical flight?

There has to be a root cause for why your cylinders did not reach your life expectations. the actual wear conditions of the components may (usually do) lend some clues as to what sensitivities may exist with this situation.

Sorry for so many questions . . . Thanks for posting your experience here so we all might learn.

You're right Bill - this little request for information doesn't take into account the wide number of variables that go into cylinder/engine life. It's not intended to be scientific - just a curiosity (most folks do like to brag if they get exceptional life out of something).

My engine is a plain-Jane 180 HP, carburated, normal compression engine that I run LOP in cruise. CHT's are usually around 330 - 350 in that condition, rarely if ever do they see more than 400 in a climb on a hot day. Has run with mags until very recently. I haven't measured the ring gaps (don't have the right tools to do it), and probably won't be able to do much more analysis.

I'm just curious how many folks have gotten this many hours on a set!

Paul

Some Data
 

1800+ hours Since Overhaul on my Lycoming Cylinders. They were overhauled by J&J Airparts using the Cerminil process Early 2000. Total time on the cylinders is 4000+ hours.

Compressions have always been 75/80 or better.

Oil consumption is ~6 hours/quart and has been that rate for all 1800+ hours. I attribute the slightly high oil consumption to excessive ground running before the first flight (11 years ago!) and some cylinder glazing.

Paul, does your engine have piston cooling nozzles? Those could have a bearing on potential life of the rings... especially when you're using moly-filled top rings as ECI does with their plated cylinders.

And, did you notice any scuffing in the cylinders (either now or previously), or only on the piston skirts?

How to tell which cylinders
 

I built my ECI 0-360 from a kit in 2008, how do you tell which type of ECI cylinders you have? So far have around 550 hours and oil consumption is around 10+ hours per quart.
Figs

Cerminil Cylinders
 

The obvious way is the painted patch on top (between pushrods) of the Cylinders. ECI Cylinders have a blue and silver stripe to designate cerminil plated process. You?ll observe Lycoming cylinders typically have a blue stripe which designates standard bore nitride hardened steel.