Cracks in 3 cylinders IO-550

[Robert C.]

After a year of trouble free flying I was expecting an uneventful Annual. Engine readouts of EGT and CHTs and oil pressure have been normal all year. 13 year old IO550  with 1300 (TIS) hrs. How naive I am/was!

Got an email from my AP-IA this morning with 3 pictures of 3 cylinders cracked between the fuel nozzle hole and spark plug hole. I'm sure we'll be talking soon to discuss next steps. Anything in particular I should know about this failure mode? Questions to ask? Solutions I should explore with him?

Thanks in advance,

Robert

[ArtVandelay]

I’m no expert, so those that are, can this be caused by over tightening of the plugs and fuel injectors?


Tom

[ilovecornfields]

http://www.tcmlink.com/pdf2/MSB09-1B.pdf
 

http://www.tcmlink.com/pdf2/SB18-08A.pdf

 

Just had a “friend of a friend”  who last week with a less than 1 year old SR-22T suddenly lost oil pressure. He declared an emergency and landed at SNA (lots of time in a 182 so he didn’t pull the chute but flew the plane down safely). Found a huge crack in his cylinder.

I had the SB above done during the last annual and no cracks were found. Thank you for the reminder that we should all pay attention to this.

[kmyfm20s]

I would Bet those are casting artifacts. I had the same concern with mine but with a little polishing and some dye it was determined it wasn’t a crack. I can’t find my original photo but here is one the you can see the same line between the injector and plug. The first picture is after an injector install and shows a similar line that is not a crack. The second picture is the cylinder that looked just like yours that we polished and dyed and is a follow up picture.

 

Edited January 1, 2020 by kmyfm20s
Forging corrected to casting

[Seymour]

30 minutes ago, kmyfm20s said:

I would Bet those are forging artifacts.

paging @carusoam to again eloquently highlight the influence of MS.   

Is there a record for 'saved AMU/minute'  based on the experience of this community?     If so,  and @kmyfm20s is correct, could this make the Top 10?    

 

[Yetti]

since they don't go all the way down, seems more like a bad cast, vs a split.

[ArtVandelay]

Is this what you’re talking about? I would go to the shop and carefully look at them in person. Kinda looks like sharpie marks?

 

 

Tom

 

[Andy95W]

Paging @M20Doc

[EricJ]

1 hour ago, ArtVandelay said:

I’m no expert, so those that are, can this be caused by over tightening of the plugs and fuel injectors?


Tom

My understanding (from A&P school) is that the typical cylinder cracks that run from a plug hole to a valve seat are often caused by over-torquing plugs.

When I was a teenager line-boy learning to fly in Germany there was another American flying club at Ramstein AFB that we used to visit once in a while.   They had a ton of trouble with cracking cylinders and blamed it on the 115/145 fuel that they (and we) got from the military.   We had zero cylinder cracking problems and were running the same fuel and the same engines (all C-150s), and I mentioned that to them several times but they weren't very interested in our experiences.    Looking back at that I bet they just had a mechanic or two that was over-torquing plugs.

 

[Robert C.]

thanks for input so far, pls keep it coming!

I implicitly trust my shop. They haven't tried to rip me off ever, and have a well deserved reputation for competence. The charter operation they are a part off got rid of their Barons because of the frequent cylinder cracking they experienced on those, so they have experience with the issue.

I just authorized them to take those jugs off so they could look at the cams/lifters/etc.

Robert

[Guest]

This is an all to common problem with the IO-550 cylinder.  We see many in the IO-550 N in the Cirrus, few in the IO-550G in the Mooney.  Forget doing a dye check, have an eddy current or LPI check done to be sure, but based on the pictures you're facing replacement cylinders.  Sadly they were likely there for some time and were missed.

As both the spark plug and fuel injector holes are straight threads its highly unlikely that over-torquing can cause this.

Clarence

[Robert C.]

Thanks Clarence. I really appreciate the time and effort you put into helping others here on Mooneyspace.

Robert

[carusoam]

So...

The IO550(N) version has shown many cylinder cracks...  N cylinders are a few pounds lighter, and are easy to spot with their alternating cooling fin style...

Few people, besides me, in the Mooney world have gone with the N cylinders... 
 

Most Mooney IO550s are born as an IO550(G) and stay that way through OHs...  Missiles are born as IO550(A)s

Cracked cylinders have not been reported much around here... when they happen in numbers... the cost of a top OH leaves a strong mark on the finance side of the brain...

See if @aviatoreb is around... he may have some experience with multiple Continental cylinders needing service... (fuzzy memory from many years ago...). 

reviewing the info above and summarizing...

1) penetrating dye tells a lot about it being a crack or not... bummer....

2) EQ3 cylinders have been known to crack in this location...  See the MSB posted by ILC above... (really looks applicable)

3) finding the EQ3 mark on the cylinder is between valve springs.... (shown in the MSB)

4) Got any JPI history to share?  (Any knowledge of how the first 1k hours were operated?)

Please Keep us up to speed on what you find next...

Ruining cylinders has always been on my mind... I have only lost one... in my first ten hours of airplane ownership... M20C stuck valve...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Robert C.]

Thanks Anthony. I checked the EQ3 info in the MSBs. Dates don't line up, my engine is about 6 months older than the ones Continental identifies.

I don't have any info on the 1st 900 hrs, other than that the previous owner started the engine with the tow bar attached. Full engine tear down and a replacement prop later she was back in the air. I put 400 or so hrs on the engine without any cylinder related issues. My AP reviewed the performance data from the G1000 (I upload to Savvy and gave him access) at every annual and neither of us ever found anomalies (other than a loose probe once.

I'll be asking my AP about doing a Eddy Current or LPI check, but suspect he won't think that necessary.

[buddy]

My A&P found the same cracks in 2 of my cylinders about 3 yrs. ago and he’s been keeping and eye on them with no change in more than 300 hrs. and I also have a 550G. 

[Cruiser]

MSB09-1B

Continental continues to be plagued with these kind of problems. It is a well know issue and many have suffered the same as you. 

[Guest]

2 hours ago, Robert C. said:

Thanks Clarence. I really appreciate the time and effort you put into helping others here on Mooneyspace.

Robert

You’re welcome.

I wish there was better news on your cylinders.  Of the many I’ve seen only one that had the tell tale visual indication was not cracked under eddy current inspection, so for a few hundred dollars for the testing it’s worth doing to confirm or deny the existence of cracks.

I’ve never seen one crack to the point of failure, but then I don’t sign them out if they’re cracked.

Clarence

 

[kmyfm20s]

1 hour ago, Robert C. said:

I'll be asking my AP about doing a Eddy Current or LPI check, but suspect he won't think that necessary.

If it has already been determined you are replacing the cylinders ask for the old cylinders back and test them yourself.  A light polish with a Dremel and a dye test after is pretty simple, I would be curious to see what you find. 

[GeeBee]

I think you should read this, especially the last part

 

https://www.savvyaviation.com/wp-content/uploads/articles_eaa/EAA_2012-06_trust-but-verify.pdf

 

3 cracked cylinders all in the same spot, don't make sense.

 

 

 

[aviatoreb]

3 hours ago, carusoam said:

 

See if @aviatoreb is around... he may have some experience with multiple Continental cylinders needing service... (fuzzy memory from many years ago...). 

 

You remember right Anthony.  About 2.5 years ago I replaced all 6 of my cylinders because of an AD.  I was forced to remove my perfectly good, mid time ECI Titan's, which were just humming/and purring with all good signs - high compressions, etc, and then put on 6 other cylinders - at no small expense.  Ah well - so it goes in this AD-negative lottery game we call aviation.

Those Titans were in fantastic shape, as is even more apparent when they are off and you can look inside at the valves, etc.  Oh well...

It was painful, but not that bad, and in my rear view mirror.

[Guest]

1 minute ago, aviatoreb said:

You remember right Anthony.  About 2.5 years ago I replaced all 6 of my cylinders because of an AD.  I was forced to remove my perfectly good, mid time ECI Titan's, which were just humming/and purring with all good signs - high compressions, etc, and then put on 6 other cylinders - at no small expense.  Ah well - so it goes in this AD-negative lottery game we call aviation.

Those Titans were in fantastic shape, as is even more apparent when they are off and you can look inside at the valves, etc.  Oh well...

It was painful, but not that bad, and in my rear view mirror.

I’ve replaced a number of Titan cylinders on TSIO520NB’s that were subject to the AD.  One of the best had a crack between the head fins straight through to the combustion chamber and was leaking exhaust gases.  We also had one blow the head right off on take off in Iron Mountain Michigan. 

Clarence

[aviatoreb]

10 minutes ago, M20Doc said:

I’ve replaced a number of Titan cylinders on TSIO520NB’s that were subject to the AD.  One of the best had a crack between the head fins straight through to the combustion chamber and was leaking exhaust gases.  We also had one blow the head right off on take off in Iron Mountain Michigan. 

Clarence

Yikes!  Really?  And you say that was "one of the best"?!  I hate to hear what were some of the worst.

Well - mine were in great shape - but with feedback like yours I feel better about that AD.  Actually - that said - I believe in the AD system even if it is painful sometimes.

[Guest]

3 hours ago, aviatoreb said:

Yikes!  Really?  And you say that was "one of the best"?!  I hate to hear what were some of the worst.

Well - mine were in great shape - but with feedback like yours I feel better about that AD.  Actually - that said - I believe in the AD system even if it is painful sometimes.

Sorry, best as in best failures, cracked all the way through.  A few more takeoffs and it may well have blown off.

Clarence

[GeeBee]

From Savvy,

"

This is the “standard” location
for cylinder head cracks to appear on Continental engines. In fact, I’ve lost two cylinders to head cracks in this exact location on my own Continental-powered Cessna 310. On the other hand, our expe- rience is that more than half of the reported cracks in this area turn out not to be cracks at all, but rather superficial cosmetic flaws in the head casting. In fact, unless the crack is clearly blue- stained and leaking fuel, it rarely turns out to be an actual crack."

[Guest]

Continental seems to take the issue seriously.

In Canada non destructive testing is to be completed by an AMO (CRS) with personnel certified to Mil STD 410.  I’ve never seen one of them use red dye, it’s always been fluorescent penetrant and UV light.

Clarence