Ring Flush, how do you do it?

[RLCarter]

Rings stick for a reason, freeing them up with snake-oil may or may not last…. Pull the cylinder(s) and fix what caused them to stick… on @A64Pilot post about Bon-Ami, I watched a guy pour Ajax down the throat of a carburetor on a VW while at a height idle (had to keep it running) , 30 minutes later it quit smoking…… side note…several months later a con-rod put a window in the case… you be the judge

[Andy95W]

Mike Busch And Savvy Aviation recommend the ring flush because it does absolutely no harm to the engine.  Pulling a cylinder is an invasive procedure that is not recommended by Mike Busch and Savvy unless absolutely necessary because of the possibility of a MIF (Maintenance Induced Failure).  I find it interesting that even though most people here respect Savvy Aviation and Mike Busch, there are so many who are so willing to shoot down their recommendation to do a ring flush as a first step, before resorting to the more error-prone cylinder removal.

And 2 years after doing this procedure, my #4 cylinder keeps chugging along happily with a clean bottom spark plug, so it definitely worked for me.

[N201MKTurbo]

I’m working with a friend on a 310. He bought some used engines. He asked me to do a compression check on one. One of the cylinders only made 10 Lbs. I told him he should pull the cylinder and fix it. He didn’t want to do that, so I said “put the cylinder TDC on the compression Stroke, fill it full of oil, gently pull the prop to force the oil through the rings.” He did it with MMO. We ran it the next day and did another compression check and it was at 65 Lbs. The oil must have loosened the rings that were probably rusted in place. The engine runs fine BTW.

[Andy95W]

Like the grizzled old A&Ps who taught me used to say, “If it’s stupid, but it works, then it’s not stupid.”

[RLCarter]

Not here to bash MB or SA, but telling people NOT to fix something is bizarre to me. Pulling a cylinder is no big deal, IF and only if it’s done correctly. The ring flush may or may not work depending on why/how the ring is stuck, but saying it does no harm to the engine is BS…. You are using hydraulics to free things up, the only place for the carbon / crud to go is into the oil sump, with no oil in the sump it just sits there until the engine is serviced with fresh oil and ran…. What to guess where it goes after start up? Personally I would put cheap oil in and run the engine a few minutes then change the oil & filter looking closely for carbon/crap being flushed out of the engine…the “Ring Flush” document above is only moving the crud to a different place in the engine, not removing it. If worried about maintenance induced failure find a new A&P

[Browncbr1]

Ring flush costs nothing and risks nothing.  Pulling a jug risks, among other things, crap getting dropped into the case, later to be found in the screen and filter.    It happens more frequently that most would assume.  

[jetdriven]

I tend to agree with most of what Mike Busch says, only pull a cylinder if it’s really warranted. Some places when they see 59 psi they pull it, sometimes even when it’s higher. Even on continental engines, where they clearly have a service letter that says it could be as low as about 42 psi and still be passing.  
on my own personal engine it was 52 psi and hissing out of the exhaust. We’re scoping it showed a heat stress valve. I was tempted to lap it in place and I probably could’ve done that, but I had a feeling the valve guide was shot which is why the valve burned… that turned out to be true so a new valve guide and valve got it fixed. But I only pulled it because it was necessary

Edited January 12, 2022 by jetdriven

[EricJ]

11 hours ago, RLCarter said:

Not here to bash MB or SA, but telling people NOT to fix something is bizarre to me. Pulling a cylinder is no big deal, IF and only if it’s done correctly. The ring flush may or may not work depending on why/how the ring is stuck, but saying it does no harm to the engine is BS…. You are using hydraulics to free things up, the only place for the carbon / crud to go is into the oil sump, with no oil in the sump it just sits there until the engine is serviced with fresh oil and ran…. What to guess where it goes after start up? Personally I would put cheap oil in and run the engine a few minutes then change the oil & filter looking closely for carbon/crap being flushed out of the engine…the “Ring Flush” document above is only moving the crud to a different place in the engine, not removing it. If worried about maintenance induced failure find a new A&P

The pressure put on the rings during this type of flush is far less than during normal operation of the engine.   Normal (proper) procedure is to flush the oil and put in fresh, i.e., do a a complete oil change, after a ring flush for the reasons you mention.    Done this way there really is much less risk than pulling a cylinder. 

If the rings are stuck due to sludge/deposits/coking/whatever and a flush cleans it up and restores compression and function, I don't see any reason to not call that a successful repair.   Since it is also a lot cheaper and easier than pulling a cylinder, it would seem to me to be a preferred method to try before resorting to pulling a cylinder.

There are all kinds of tricks to do cylinder maintenance in-place, many of which are described in the engine manuals.   Lapping valves, changing valve train parts, etc., etc., all have time-proven methods to be done in-place without pulling the cylinder.   A ring flush seems less complex than most to me.

[A64Pilot]

Just took Concorde’s IA renewal class online this morning.

The number 1 engine maintenance induced failure is incorrectly torqued cylinders, 

Having said that all it says is there are a lot of sloppy mechanics out there, not pulling a cylinder that’s in trouble makes as much sense to me as not adjusting timing when it’s out, because some have left the mags incorrectly torqued.

Does Lycoming recommend a “ring flush”? Is it in their manual? If not, then how do you explain to an inspector why you did the procedure?

Whats that logbook entry look like? or is this one of those put in on sticky and not in the book?

Edited January 14, 2022 by A64Pilot

[kortopates]

Mike Busch And Savvy Aviation recommend the ring flush because it does absolutely no harm to the engine.  Pulling a cylinder is an invasive procedure that is not recommended by Mike Busch and Savvy unless absolutely necessary because of the possibility of a MIF (Maintenance Induced Failure).  I find it interesting that even though most people here respect Savvy Aviation and Mike Busch, there are so many who are so willing to shoot down their recommendation to do a ring flush as a first step, before resorting to the more error-prone cylinder removal.
And 2 years after doing this procedure, my #4 cylinder keeps chugging along happily with a clean bottom spark plug, so it definitely worked for me.

that’s great to read. We’ve saved a lot of cylinders with the ring flush cocktail and made a lot of folks happy. It’s not always just one cylinder either. But it doesn’t always work and sometimes the solvent needs to sit in the cylinder over night to get some particularly caked rings unstuck. But when it works everyone’s happy.


Sent from my iPhone using Tapatalk

[LANCECASPER]

1 hour ago, A64Pilot said:

Just took Concorde’s IA renewal class online this morning.

The number 1 engine maintenance induced failure is incorrectly torqued cylinders, 

Having said that all it says is there are a lot of sloppy mechanics out there, not pulling a cylinder that’s in trouble makes as much sense to me as not adjusting timing when it’s out, because some have left the mags incorrectly torqued.

Does Lycoming recommend a “ring flush”? Is it in their manual? If not, then how do you explain to an inspector why you did the procedure?

Whats that logbook entry look like? or is this one of those put in on sticky and not in the book?

Since the number one reason for engine failure after maintenance is improper Cylinder Torque, doesn't your graphic support the idea that if you can avoid removing the cylinder, why not try something simple, less invasive first?

[A64Pilot]

1 hour ago, LANCECASPER said:

Since the number one reason for engine failure after maintenance is improper Cylinder Torque, doesn't your graphic support the idea that if you can avoid removing the cylinder, why not try something simple, less invasive first?

No, the FAA graphic supports doing the job correctly.

Some of the bolts on most engines that hold on cylinders are thru bolts, they go through the engine and the opposite side and of course provide clamping force that holds the engine together. These bolts are a tight fit in the case, they have to be or they would leak oil, tight enough so that it’s very possible that torquing only one side won’t provide the full tightening required as the bolt may bind in the case and the other side could be loose.

The issue is apparently some mechanics just torque the nuts on the cylinder they removed, this is fine for old Radials and even some older motors like C-85’s who’s studs aren’t thru bolts, but on more modern motors where they are, the nuts on the opposite side must also be torqued, but this is sometimes a lot more work as baffling etc has to be removed on both sides of the engine.

The engine manual of course requires both sides be torqued, but apparently some don’t.

If the manual is followed, their wouldn’t be a problem.

That’s the root of my disagreement, it’s not so much that a ring flush might not work, but one of the engine is telling you it needs maintenance and you decide to do a an undocumented and unapproved procedure and later it fails from broken rings or whatever, it’s tough to defend your actions then.

Now if you called Lycomings help desk and they sent you a letter outlying the procedure, then sure, I’d do it.

Strike up a conversation sometimes with an FAA inspector and ask what their opinion is of procedures that aren’t documented anywhere.

I may be wrong, maybe it is a documented and approved procedure, but I suspect it’s not.

For example doing things like applying fuel tank sealer, or JB weld to a crankcase seam to stop an oil leak has also been tracked to engine failures as it’s masking improperly torqued thru bolts.

As has the use of silicone sealer on cylinder base O-rings and thru bolts, all are seeming acceptable practices from automotive mechanics, but are not approved on aircraft, and have led to engine failures, specifically incorrectly torqued 

Edited January 14, 2022 by A64Pilot

[LANCECASPER]

1 hour ago, A64Pilot said:

No, the FAA graphic supports doing the job correctly.

Of course, but if the cylinder doesn't have to be removed, and there's a chance that a ring flush just might work, there's no need to worry about whether it was re-installed and torqued correctly.

I imagine in the early stages of dentistry a cavity meant that they pulled the tooth. Later on they learned that if they drilled and filled, even though it seemed like heresy at the time, you were good to go, always with the option of pulling the tooth later.

[A64Pilot]

22 hours ago, LANCECASPER said:

Of course, but if the cylinder doesn't have to be removed, and there's a chance that a ring flush just might work, there's no need to worry about whether it was re-installed and torqued correctly.

I imagine in the early stages of dentistry a cavity meant that they pulled the tooth. Later on they learned that if they drilled and filled, even though it seemed like heresy at the time, you were good to go, always with the option of pulling the tooth later.

I have a lot of Dentists in my family, and of course your correct.

Not too long ago it was normal for a young girl to have ALL her teeth removed, often before marriage because of course they could get caries (tooth decay)

https://boldfeed.io/en/removing-your-teeth-was-a-perfect-wedding-gift/

 

There are a few problems, first off as a licensed mechanic I am accountable and liable for my work. The FAA requires any work to done to approved data, or at least acceptable data. I can’t for instance pour Risolene in your oil, which is advertised to free stuck rings in Auto’s and may work for all I know. Now if Risolene said FAA approved, then I could use it.

I have to have some kind of data that supports what I’m doing. I can’t just cook up something and do it.

Secondly it’s logical to assume that a ring flush won’t fix whatever it was that caused the rings to stick to begin with. In an instance like this I believe some troubleshooting should be done to determine and correct the cause of the stuck rings. Flushing them is treating the symptom without determining what’s wrong to start with.

Edited January 15, 2022 by A64Pilot

[kortopates]

Mike's January article on "Cylinder Rescue" covers both Valve Lapping and Ring Flush to successfully "rescue" a couple cylinders this past month.

https://resources.savvyaviation.com/wp-content/uploads/articles_aopa/AOPA_2022-01_cylinder-rescue.pdf

[LANCECASPER]

10 minutes ago, kortopates said:

Mike's January article on "Cylinder Rescue" covers both Valve Lapping and Ring Flush to successfully "rescue" a couple cylinders this past month.

https://resources.savvyaviation.com/wp-content/uploads/articles_aopa/AOPA_2022-01_cylinder-rescue.pdf

21st Century thinking vs. 19th Century thinking   

[carusoam]

That’s a timely article…

Or Mike is reading along with us on MS….   
@kmyfm20s see Paul K’s post above…. If you haven’t seen it already….

Best regards,

-a-

[M20TN_Driver]

I have yet to perform the flush on my Acclaim.  My engine is at 2011 hours since new, so the thought by Mike Busch and team is that it is likely a gummed up ring.  Regardless, the flush is supposed to tell you a lot.  If you turn the prop and there is little resistance to the flush mix, then you know you have a bigger issue.  There is supposed to be good resistance with the prop turn when this is done.  My compressions are all good and #3 cylinder (the one that is perpetually oily soaked bottom plug) is believed to be the culprit.  #3 doesn't run hotter on EGT or CHTs than any other cylinder.  Last oil change virtually nothing in the filter so I believe this engine has plenty of life left in it prior to overhaul.  I run fine wires in it, which is why I think the engine still runs well being oil soaked.  I was told that a massive plug likely wouldn't even fire with that much oil on it.

I have tried running MMO in the oil, and even running a can of SeaFoam through it to see if it improved.  I just ground ran the Seafoam for an hour and then did an oil/filter change.  

I'm trying to least invasive procedures first.  If they don't correct, I'm going to bite the bullet and do the full ring flush.  The issue with the Acclaim is that you have to remove the intercooler to even access the top #3 plug and you have to remove the quick drains too as the mix will soften O-rings...which would be no bueno.

I mostly run this engine LOP.  It was run exclusively LOP before I bought it a few years ago.  I don't think LOP or ROP has much to do with the oil sludge gumming up rings.  I'm not a mechanic, so I could absolutely be wrong on that.  I do know I baby these cylinders and rarely are they run over 350 degrees except on takeoff.  In normal LOP cruise they are all mostly around 300 degrees on CHT.

 

 

[carusoam]

10 hours ago, M20TN_Driver said:

I have yet to perform the flush on my Acclaim.  My engine is at 2011 hours since new, so the thought by Mike Busch and team is that it is likely a gummed up ring.  Regardless, the flush is supposed to tell you a lot.  If you turn the prop and there is little resistance to the flush mix, then you know you have a bigger issue.  There is supposed to be good resistance with the prop turn when this is done.  My compressions are all good and #3 cylinder (the one that is perpetually oily soaked bottom plug) is believed to be the culprit.  #3 doesn't run hotter on EGT or CHTs than any other cylinder.  Last oil change virtually nothing in the filter so I believe this engine has plenty of life left in it prior to overhaul.  I run fine wires in it, which is why I think the engine still runs well being oil soaked.  I was told that a massive plug likely wouldn't even fire with that much oil on it.

I have tried running MMO in the oil, and even running a can of SeaFoam through it to see if it improved.  I just ground ran the Seafoam for an hour and then did an oil/filter change.  

I'm trying to least invasive procedures first.  If they don't correct, I'm going to bite the bullet and do the full ring flush.  The issue with the Acclaim is that you have to remove the intercooler to even access the top #3 plug and you have to remove the quick drains too as the mix will soften O-rings...which would be no bueno.

I mostly run this engine LOP.  It was run exclusively LOP before I bought it a few years ago.  I don't think LOP or ROP has much to do with the oil sludge gumming up rings.  I'm not a mechanic, so I could absolutely be wrong on that.  I do know I baby these cylinders and rarely are they run over 350 degrees except on takeoff.  In normal LOP cruise they are all mostly around 300 degrees on CHT.

 

 

Oddly,

You revived this thread about two months ago….

You gave no feed back regarding the questions like engine hours and cylinder hours….
 

Stay with me for a moment…

2011 hours is a lot for a set of IO550 cylinders even NA ones… a real lot…

Keep in mind… when an Acclaim is run in fire breathing mode… it is a challenge to get them to 1000hrs… a real surprise for some owners…

You said your mechanic wasn’t very familiar with the flush procedure…  how about his experience level with a TN’d IO550?

 

 

There are some materials that are approved to be put in aircraft engines….

And some stuff never sought approval to be used…

 

I’m not a fan of MMO… and avoided putting it in a firebird with a much lower cost engine…

Two or three whole firebirds = about one Acclaim engine… (for context)

 

Did you post pics from inside the cylinder yet?

Often, hands on owners get the usual dental cam that is perfect for this activity…

They post pics of the valves and cylinder walls….

Chances are there is enough evidence of what is going on from that… there is less guessing and putting things in your engine experimentally…

TN’d IO550s are too expensive to take an experimental approach…

Why go there?

Have you ruled out cylinder wall cross hatch pattern? (Still there, or polished smooth?)

Have you ruled out broken oil ring, or is it still there?

To get oil into the cylinder… the seal has something wrong, or the surface it is sealing against has something wrong…

Kinda Cleaning those surfaces by flushing them with MMO is unlikely to fix worn or broken parts…

Its much better to use the maintenance manuals for this fine bird…

See if you can get your mechanic to take pics with a dental camera… even if you have to buy the camera for him to use… it is a great tool for an owner to have to document valve and cylinder surface health as the engine ages…

 

For fun… search for MMO and the other stuff around here… see what mechanics say about using it in certified engines…

Some things make less sense when used in airplanes… they even make even lesser sense when it comes to more expensiver airplanes…

 

Has anything changed in the last two months?

How many hours have you accumulated in the last two months… (not flying at all?)

Do you want to keep running the engine with engine oil entering the cylinders…?

Unlike a NA engine… where the oil gets dumped overboard…

The TC’d engine dumps that oil through the hot side of the turbo….

PP thoughts only, in my best friendliest voice I can type with… not a mechanic…

Best regards,

-a-

[carusoam]

Keep in mind…

Cylinder wear is a normal part of a TC’d engines life…

The number five Cylinder is often the hottest… for a reason…

Methodically rule things out in accordance with the manuals is a great way to preserve an engine for longevity…

Lets see what you have going right…

And see what may be plainly visible…

If the cylinder surface has excessive wear… for whatever reason… now is a good time to find out…

Often, some cylinders get rust marks from sitting too long…some marks are really deep poc marks… and allow oil into the cylinder…

Some cylinders have evidence of scratches in them… left from when something broke or got ingested…

Say everything inside the cylinder is in perfect condition…

And oil is entering the intake system from somewhere….

With a TN’d engine… that somewhere could possibly be a turbo seal that is leaking oil into the intake…

With 2011 hours on the tach… be on the look out for really worn parts…

You have done a great job of getting the acclaim’s engine and cylinders to this exalted level…

You must be doing something right to go this far…

How much further do you think you can get this cylinder to go?

Get some pics… look for the cross hatch…

If it is worn clean off…

You can celebrate it for going the distance!  
 

Then we can start discussing proper cylinder OHs…

Start putting a plan together…

Engine OH is not too far away…

Running it until something breaks is not an economically feasible solution…

Have you seen the OH costs for the TN’d IO550?

Running past TBO is done by many people…  to be successful… it often requires knowing the entire history of the engine… not, just the hours the last owner has put on…

Tell me again… these cylinders all have 2011 hours on them… really?   If so, that in itself is amazing…

Best regards,

-a-

[carusoam]

If for some reason…

Your mechanic isn’t familiar enough with the TN’d IO550…

We have a mechanic around here that is really good at getting other mechanics up to speed on that particular engine… and it’s systems…

That same engine shows up in a more common airplane…. With a parachute… 

Be on the look-out for the Mooney shop, that also takes care of the parachutes on the side….

Let us know if you need or want more guidance than that…

Best regards,

-a-

[LANCECASPER]

20 hours ago, M20TN_Driver said:

I have yet to perform the flush on my Acclaim.  My engine is at 2011 hours since new, so the thought by Mike Busch and team is that it is likely a gummed up ring.  Regardless, the flush is supposed to tell you a lot.  If you turn the prop and there is little resistance to the flush mix, then you know you have a bigger issue.  There is supposed to be good resistance with the prop turn when this is done.  My compressions are all good and #3 cylinder (the one that is perpetually oily soaked bottom plug) is believed to be the culprit.  #3 doesn't run hotter on EGT or CHTs than any other cylinder.  Last oil change virtually nothing in the filter so I believe this engine has plenty of life left in it prior to overhaul.  I run fine wires in it, which is why I think the engine still runs well being oil soaked.  I was told that a massive plug likely wouldn't even fire with that much oil on it.

I have tried running MMO in the oil, and even running a can of SeaFoam through it to see if it improved.  I just ground ran the Seafoam for an hour and then did an oil/filter change.  

I'm trying to least invasive procedures first.  If they don't correct, I'm going to bite the bullet and do the full ring flush.  The issue with the Acclaim is that you have to remove the intercooler to even access the top #3 plug and you have to remove the quick drains too as the mix will soften O-rings...which would be no bueno.

I mostly run this engine LOP.  It was run exclusively LOP before I bought it a few years ago.  I don't think LOP or ROP has much to do with the oil sludge gumming up rings.  I'm not a mechanic, so I could absolutely be wrong on that.  I do know I baby these cylinders and rarely are they run over 350 degrees except on takeoff.  In normal LOP cruise they are all mostly around 300 degrees on CHT.

 

 

Hopefully the ring flush is successful on this cylinder, but even if it's not, if all of your other cylinders are good, a new cylinder would probably be worth it, and then fly it on condition. 

[A64Pilot]

Talking about maintenance induced failures, what’s even more frequent is an engine giving indications it’s in trouble, but the owner not wanting to listen and trying home brew fixes or just hoping it will just get better on its own, and then it fails at some bad time.

We mechanics aren’t allowed to just make up procedures, we aren’t allowed to put MMO in oil although I’ve seen it many times and never seen any harm.

So it starts with MMO, but you know my oil pressure is low now, how about a couple cans of STP? Fixed my uncles tractor. Or I have oil leaks, NAPA sells some stuff to stop leaks?

As a mechanic I’m no more allowed to do a “ring flush” than I am to pour Bon-Ami into the suck side of the engine when it’s running, probably less as I can at least show on one engine where the Bon-Ami was approved by the Manufacturer.

 Now the minute Lycoming or Continental publishes a procedure, then I’m on it, but until I can show some kind of approval I don’t see how it can be done Legally and the day an engine fails or doesn’t produce enough power due to broken rings and my signature is in the book signing off a ring flush, bad things are likely to happen, lawsuit, FAA sanction etc.

I’m not saying a ring flush will break rings, but I am saying that stuck rings is not a normal condition and instead of treating the symptom, you need to investigate why they are stuck, very likely they are worn to the point that excess oil is getting by, coking and sticking them, worn rings break frequently.

[LANCECASPER]

37 minutes ago, A64Pilot said:

Talking about maintenance induced failures, what’s even more frequent is an engine giving indications it’s in trouble, but the owner not wanting to listen and trying home brew fixes or just hoping it will just get better on its own, and then it fails at some bad time.

We mechanics aren’t allowed to just make up procedures, we aren’t allowed to put MMO in oil although I’ve seen it many times and never seen any harm.

So it starts with MMO, but you know my oil pressure is low now, how about a couple cans of STP? Fixed my uncles tractor. Or I have oil leaks, NAPA sells some stuff to stop leaks?

As a mechanic I’m no more allowed to do a “ring flush” than I am to pour Bon-Ami into the suck side of the engine when it’s running, probably less as I can at least show on one engine where the Bon-Ami was approved by the Manufacturer.

 Now the minute Lycoming or Continental publishes a procedure, then I’m on it, but until I can show some kind of approval I don’t see how it can be done Legally and the day an engine fails or doesn’t produce enough power due to broken rings and my signature is in the book signing off a ring flush, bad things are likely to happen, lawsuit, FAA sanction etc.

I’m not saying a ring flush will break rings, but I am saying that stuck rings is not a normal condition and instead of treating the symptom, you need to investigate why they are stuck, very likely they are worn to the point that excess oil is getting by, coking and sticking them, worn rings break frequently.

There's a big difference in running the engine with STP and using a solvent to loosen up something stuck by turning it through. Kroil's isn't FAA approved but it sure does loosen things on an airplane that won't move otherwise. Every mechanic worth their salt has a few tricks of the trade. Once they have seen them work they use them. The ones that didn't work they discard. Mike Busch, who's also a mechanic has used it and has seen it work for others as well and under the Savvy Maintenance recommends it to others before more invasive procedures. If publishing it in his books, talking about it at his seminars and writing an article about it in AOPA Pilot (https://resources.savvyaviation.com/wp-content/uploads/articles_aopa/AOPA_2022-01_cylinder-rescue.pdf) doesn't get an FAA sanction, I think he's in the clear.

[A64Pilot]

I can’t understand or explain why he hasn’t had a visit from the FAA.

Using Kroil or other penetrating oil to loosen stuck bolts is orders of magnitude different than pouring a witches brew of chemical to flush carbon down into the oil pan.

By that logic why not remove the plugs and stick a steam cleaner in there to decarbonize the engine?

I understand we disagree, just trying to get you guys to understand why your mechanic may not embrace this ring flush thing

 

Edited March 23, 2022 by A64Pilot