Cracked Cylinder

[Seth]

Well, 100 hours into a newly overhauled engine, I lost a cylinder, and may have damage to a second.

After reading the post on Red Board (AOPA) when I noticed the increased CHT in cylinder 2, and immediatly kept a hawkeye on it. Long story short, I pulled back power to keep the temp below 450, and then back down to the 380 to 400 range and let ATC know I was having an issue. After landing (at my home base) I had one of two shops I use look at it (the one based at GAI) and we thought it was an induction leak. The engine still ran rough and hot, and the compression was 0. You could hear the air hissing out of the cracks.

Unfortunately, cylinder 4 also has a lower compression at this point, yet the other four cylinders have compressions in the 70s.

The shop that did the overhaul is backing up their work, and will send out two replacement cylinders - but this is very concerning for a newly overhauled engine.

I'll give pictures and updates as to what we think caused this issue on a newly overhauled engine 5% into it's lifecylce.

-Seth

[KSMooniac]

Did they use new cylinders, and if so, which ones? Do you have engine monitor history since the overhaul?

Congrats on keeping your wits and getting it back to home safely, BTW.

[201er]

Ouch. Sorry to hear that. Any abnormal flying go down lately? What kind of power/mixture have you been flying?

[John Pleisse]

What shop was it Seth? Backing up their work is nice, but it shouldn't have happened in the first place. Online discussions delge into nano-detail about efficiencey, temps, operational issues so much, that basic safety is often overlooked.

[jetdriven]

I agree with John, there is no reason a conforming certified aircraft engine should have this kind of problem at 100 hours. New cylinders? LOP/ROP operator? average CHT?

[aviatoreb]

Well, 100 hours into a newly overhauled engine, I lost a cylinder, and may have damage to a second.

After reading the post on Red Board (AOPA) when I noticed the increased CHT in cylinder 2, and immediatly kept a hawkeye on it. Long story short, I pulled back power to keep the temp below 450, and then back down to the 380 to 400 range and let ATC know I was having an issue. After landing (at my home base) I had one of two shops I use look at it (the one based at GAI) and we thought it was an induction leak. The engine still ran rough and hot, and the compression was 0. You could hear the air hissing out of the cracks.

Unfortunately, cylinder 4 also has a lower compression at this point, yet the other four cylinders have compressions in the 70s.

The shop that did the overhaul is backing up their work, and will send out two replacement cylinders - but this is very concerning for a newly overhauled engine.

I'll give pictures and updates as to what we think caused this issue on a newly overhauled engine 5% into it's lifecylce.

-Seth

Ugh. So sorry to hear it but so happy to hear that you are safe and sound. For whatever reason, be it build errors or infant death syndrome of parts, I have read that the first several hours and even up to the first 250 hours of an engines life are a time of increased failure.

[N33GG]

Ugh. So sorry to hear it but so happy to hear that you are safe and sound. For whatever reason, be it build errors or infant death syndrome of parts, I have read that the first several hours and even up to the first 250 hours of an engines life are a time of increased failure.

It is called the bathtub curve for a good reason. High risk at first, then decreasing, followed by a long period of low risk, and then a rising risk of failure.

Beware of the bathtub curve!

[jetdriven]

We have 50 hours on a fresh OH and haven't made a single adjustment, repair, or turned a screw. Haven't taken a tool to it. Infant mortality is one thing, losing 2 cylinders on a 6-cylinder engine is another.

edited. 50 hours.

[scottfromiowa]

Sorry to hear this Seth. Keep us posted on details.

[Seth]

Thanks for the replies. Until I'm sure how the warrenty will be taken care of I'm going to personally be careful of what I write. I'll get as many details as possible out there. I do however feel that there is no way that cylinder should have failed, the second one shouldn't have low compression, and I'm worried that I may have a bad batch of cylinders. I have spoken to a separate overhaul shop and they noted that this should not happen (as did the place that overhauled the engine) and that we may need to contact the manufacturer as there may be a defect in the cylinders.

Bolduc is the company in Minnesota that overhauled the engine which was delivered in late September 2012 to the mechanic I used at BBB to install the engine. He also conducted the pre-buy inspection and caught the fact that there was metal in the oil filter after the test flight.

We'll know more once Bolduc gets a good look at the two bad cylinders.

Facts:

ROP operation

Very little oil consumption (extremely little)

Complete engine monitor stats since overhaul - I just need to download them to the flash drive.

First sign of an issue was the rise in CHT of the #2 Cylinder. I had it looked into and it was indeed a cracked cylinder.

#4 has compression in the low 60s. The others four are in the 70s.

Rarely was any cylinder over 400 CHT during any climbout and often the temps were in the 380 range.

#5 cylinder tended to show higher EGT by about 40 to 80 over the rest, but that was determined to be a faulty probe that when switch with another cylinder's, the EGT was then higher on the switched cylinder - so now issue there.

These cylinders were new as part of a Top Overhaul to the engine 200 hours prior to my purchasing the aircraft. Instead of throwing good money after bad, when we looked into what was causing the metal in the oil filter we found that a bottom end repair was needed (lifters, other issues), and I decided to overhaul the engine and used that as part of the negotiating tool to purchase the airplane. So, the new cylinders with 200 hours since new were overhauled and have 100 hours on them since overhaul, meaning they have approsimately 300 hours total time.

More information to follow . . . and thank you again for any wisdom. The engine ran very smooth except for this issue so far.

-Seth

[jackn]

Seth, could you tell us who was the manufacturer of the cylinders? My understanding is that the big bore continental cylinders don't have a lot of extra meat to be re-ground.

[N601RX]

Assuming the intercylinder baffling was installed correctly and there wasn't some localized overheating going on, its hard to imagine that this is anything that the engine shop or installing mechanic did incorrectly. The other possibility other than bad castings is although they had low hrs, there isn't anyway of knowing how hot the original owner ran them.

Where was the crack? The plane 2 hangers down from me had a cylinder crack all the way around and blow off last year.

[Piloto]

Most of the cylinder cracks that I have heard happened on overhauled cylinders with over 3000hrs. Unlike other parts of the engine the cylinders are stressed in tensile cycle mode. This creates an eventual weakening of the metal that is impossible to predict by inspection. The best way to go is with new cylinders from a well known source like the engine manufacturer.

José

[Seth]

Cylinders are ECI Nickel

[jackn]

No Kidding? On another post I had mentioned that a friend of mine who has an A36 Bonanza with a 550 conversion had one of his new ECI cylinders crack and fail. Apparently his was not the only one. ECI knows this & I believe there is now an AD detailing an inspection procedure.

[Seth]

Well that is the same setup I have. The 550. I just found out about the AD myself and will bring this to the attention of both shops - that being said, I'm sure they knwo about it. As I have more informaiton, I'll post it.

-Seth

[KSMooniac]

Good luck. Hopefully ECI will stand behind their product and cover all of your expenses.

[Seth]

I am replacing the two cylinders. I do have a question however. If the other four cylinders are nickel plated, does it matter if I replace the two problematic cylinders with non-nickel alternatives? Such as a new steel cylinder or even a differenet brand, such as non-ECI?

Thoughts.

-Seth

[jackn]

I don't see any issues other than you oil analysis numbers might be a bit off. The question I have, is if the other 4 cylinders fall into th s/n that fall under the AD, your having to inspect every 30 hours shouldn't be your problem. I would call the president of ECI and make the case that they should replace all the cylinders. My friend did this and they agreed.

[Seth]

I'll check the S/N - that's a good piece of advice.

-Seth

[KSMooniac]

Did 2 cylinders fall in the AD range, and 4 didn't? You can certainly run a mixed bag of cylinders, but if you bought 6 new ones at overhaul I wouldn't trust those other 4 and would insist on giving them back to ECI for full credit, plus your expenses. Be assertive.

[Seth]

Update: I should have been even more diligent in learning about the Top Overhaul that was performed prior to ownership and insisted on new cylinders when I performed my overhaul.

My cylidners were not new as of the time of the Top Overhaul.

In 2007, ECI overhaueld Continental Cylinders with the nickel finish and Wilmar in Minnesota installed them as part of the Top Overhaul on my aircraft's engine. I will go back into the log books to figure out if these were the original continental cylinders or if they were separately overhaueld continental cylinders.

In 2011, I had the entire engine overhaueld and we had Bolduc, also located in Minnesota, conduct the overhaul, replace the necessary parts, and inspect the cylidners to be reused in the new run of the engine. They say they stand behind their work and will cover a certain portion of the costs.

Still, one cylinder cracked and another has low compression less than 300 hours after it was overhauled (200 since the top and then 100 since the full engine overhaul), but not new.

The ECI warrenty is only for one year on overhauled cylinders. They are wiling to give me a price break on their new cylinders both steel and nickel plated. These cylinders are not part of the AD.

I am not yet sure what Buldoc is willing to offer, but they do understand that it was their work that went bad 11 months and 100 hours after overhaul, and as stated, they will stand behind their work. I'll find out Monday their offer. I hope they'll cover the one cylinder and the labor for that cylidner. The "okay" cylinder that I'm also replaicing I'm guessing they will not cover but will give me a large disocunt on.

One cylinder is cracked, the other is off. Buldoc reccomends that I simply replace the two cylinders with new cylinders since it's already off (the one that had lower compression but was still "fine").

Buldoc does not reccomend ECI at this time for the two new cylidners I am going to install. They are a Superior dealer and suggest either Millenium or Continental Cylinders. They of course reccomend Millenium.

If I were to install Continental Cylinders - they would look exactly like the others. I do not plan to sell the Mooney Missile (really ever at this point - I may own a share of another aircraft in the future, but I plan to always keep the Missile - seriously - 60+ year hold) but should I sell it, it would look awefully weird to the buyer with four ECI Overhauled Continental Cylinders and two Millenium Cylinders, though at this point I do not expect the other Cylinders to last the full TBO - maybe they would all slowly switch to Millenium in time. I hate that my confidence is not in the engine anymore. That being said, the other four all have high 70s compression and may very well make it a long time into this engine run.

ECI is going to give me a price break on new cylinders should I purchase through them and Bolduc is going to give me their warrenty offer (to an extent) on Monday. I'm not sure what to expect, but I know I'll be out of pocket to a certain extent.

Options:

I am going to install two new cylinders regardless at this point. I can also sell the "used" cylinder for a small recoup cost.

1. Install Contiental Cylidners - (2 steel vs 4 ECI Nickel) - Most expensive option - Engine looks uniform

2. Install Millenium (at a better price) (2 steel vs 4 ECI Nickel but a better chance of lasting accoring to Bolduc (and mismatched visuallly looking)

3. ECI at a lower price as they are willing to work with me - but they are ECI and I am not thrilled at this point (even though they say they have conducted a lot or R&D and their new cylinders are much better). I could go Nickel on all cylinders or just get two steel anyway. Cylinder heads may or may not match - I'd have to check on that.

So, you get what you pay for, unfortunatly sometimes, but in this case, I'd love to hear your thoughts. If I could do it again all over, I would have paid the money up front during the overhaul for new Millenium Cylinders (at the time).

That's where I stand right now. It'll be my guess between $3,000 and $4,000 before all is said and done with cylinder cost plus labor.

Thanks again,

-Seth

[KSMooniac]

Ugh. I don't envy you. Quite the dilemma, but I'd encourage you to consider replacing all 6 at this time since you've lost confidence in them. It sounds like you don't know the history of them, especially total time, and that would worry me. Assuming the plane is a keeper as you mentioned, I would rather bite the bullet once now for the extra 4 jugs vs. dealing with sporadic replacements in the future, which may leave you stuck somewhere away from home where you'll be at the mercy of a strange shop. I don't know if the IO-550 is at all like my IO-360 regarding cylinder R&R, but removing 1 required quite a bit of disassembly to the point that doing the 2nd one on the same side wasn't much additional work. (ie removing baffling, induction tubes, exhaust, etc.)

You might venture over to beechtalk.com since there are a lot of Continental operators and experts over there. I'm not sure what the favorite cylinder is currently, but I do know that a lot of the savvy owners are buying new CMI (formerly TCM) and then getting them re-worked by a competent shop to make sure the valve fits are properly done since there continue to be problems with them from the factory. I don't know how ECI or Superior compare, but their AD history is frightening to me.

[jackn]

I would replace all 6 'while you're at it'. You are going to have to break in the new cylinders anyway, as this is critical to their performance. All the pre-disassembly will have been done. You will feel confident in you engine! I'm not a big believer in 'new and improved' unless there is a lot of data that it is indeed 'improved'. I used TCM cylinders when I did my top end last year. Took the time to break them in. I fill up w 8 quarts, no oil on the belly, use 1 qt in 30 hrs, and the oil never turns black. Oh yea, oil temp dropped by 20 degrees.

[jetdriven]

WHat a disaster with mixed cylinders so soon from OH. I an with Scott, go check on BT and ask then what to do. Continental 520s are their thing.