Question for the Mechanics

[DWood]

I don't believe that would be legal for any A&P to do, but not a surprise coming from Mike Busch.

[Ryan Smith]

I don't believe that would be legal for any A&P to do, but not a surprise coming from Mike Busch.

Mike’s company killed a guy with bad advice on a Baron 58 locally here. First flight after long term maintenance after eating a piston on an engine past TBO that they said to more or less replace the piston and run it with frequent oil changes to get all the serial numbers out of the engine. It blew on takeoff and the airplane VMC rolled into the ground and burned. I pass by the accident site on I-85 every time I head to work and think of the scorched grass and incinerated wreckage that was there for several days. You could have fit the remainder of the airplane in a 55-gallon barrel.

To add insult to injury, about a year later, they published that as a success story saving the owner money on an overhaul that the shop was trying to “bully the owner into getting”. They photoshopped a picture of the airplane with an altered N number and ignored me calling them out with the original picture of that airplane.

I lost every bit of what little respect I had for Mike after that.

[ghostflyer]

As George mentioned , use your own cylinders for overhaul as the history of cylinders from an engine overhauler isn’t known . A lot of cylinders are changed for various reasons .
Some cylinders are repaired due to cracking and the new owners are not told of the amount /type of repairs carried out . Personally I always buy new cylinders ,rings ,pistons .
“Some “ engine overhaulers will give you a trade in price on your old cylinders when you buy on new cylinders from them.

[dstates]

… You mentioned a drippy oil breather, if one or more of your cylinders are allowing
excessive combustion gasses passed the rings you may be pumping the oil out thru blow by out the breather tube. A for instance was my O-300 would use about a quart in six, all my compressions always showed high 60s and low seventy's, there were three ( low cyl ) and one in particular would blow passed the rings. I changed one of the cylinders last annual due to in addition to low comp test, it started to show signs of
oil fouling on the lower plug. upon diassy I found the oil control ring and two of the compression rings coked up and seized. so I recondition a spare cylinder threw, a new piston with rings and installed, now even though the other two cylinders are on the low side there not pumping oil as much, I'm now using a quart in every 15 hrs or so and a cleaner underside. …

Anybody have experience doing this oil control ring solvent flush? If so, what were the results?

I had a cylinder at 35-40 on a compression test this winter during annual. My A&P (IA) and I did the flush. It was successful and got the compressions back up to mid 60's (cold). We tried other things first, but ended up getting the most gain from the flush.

[Bruce Fenstermacher]

I first heard of this on an Aeronca forum. Thought it to be an old school mechanic sort of thing. I checked with a friend of mine very familiar with all sorts of old and new aircraft engines. He told me his dad use to drain oil and run kero instead to clean out the engine. But this is different. He just laughed at the idea, but he didn't say it is a crazy idea. He did go so far as to say you won't find that procedure in a brand X engine company SB.

And now we see a Savvy procedure for it.

Over the last 3 years working primarily on SR-22s I've seen a lot of cylinders condemned for low compression 9 times out of 10 when we pull the cylinder the bottom scraper ring and the oil ring are so stuck in there piston ring lands they could not have been working. And I have doubts no matter how careful we were we wouldn't be able to get the rings unstuck. This happens IMO because Cirrus pilots run their engine on the ragged edge of overtempting (as they are taught by Cirrus) and they cook the oil.

I've often wondered if a 100 hrs operation with MMO in the oil wouldn't free some of these rings up. But of course we couldn't consider that in a customers airplane.

Many of our customers are also SAVVY customers. I wonder how long it will be till one of them or SAVVY directs us to perform this procedure.

I've spent a good amount of time around old time mechanics and I've seen lots of stuff performed you just shake you head in wonder but cant argue with their success. I've been thinking about this procedure and can't really think of any reason why not. What could it hurt. Not that I'd be jumping to do this to a customers plane unless of course SAVVY is taking full responsibility.

[voorheesh]

For consideration (Its been alluded to but not specifically):

The procedure of flushing cylinders promoted by Savvy Aviation is aircraft maintenance and subject to Part 43. 43.13 Performance Rules, prescribes that methods, techniques, and practices must conform to standards set forth by manufacturers or other appropriate sources. It must be recorded (including description of work) in the maintenance records and signed by a technician or repair station. Is this flush prescribed in any maintenance manual, Service Bulletin, or other approved source? AC43.13, maybe? I have no idea; but if not, aren’t we rolling the dice doing something like this? It may work well in some cases, but the ultimate effects maybe unknown and might well increase safety risk.

[Bruce Fenstermacher]

Is there a written procedure for everything a mechanic does. In theory the FAA correct answer would be yes. But in the real world I'm not so sure we make theory 100 percent reality. Yes, there are a lot of documented procedures from all sorts of sources. So many in fact that a mechanic could be following one and not know the document exists but his procedure is what he was taught. And then there is mixing of procedures between manufacturers products. For example did you know Lycoming has a SB that describes "the rope trick" and it is used in conjunction with a "wobble" test of valve stem to valve guide clearance on ALL Lycoming engines. They also describe how to properly ream a guide and the clearance it should have. Continental s got nothing. That's right no written procedure I've ever found. Is it because Continental valves and valve guide clearance never gets too tight? No, in fact I'd say Continental engines 0300 and smaller have a worse problem than Lycoming when run on 100ll. Yes you can look in a Continental overhaul manual and find all the information you need to measure and ream guides like Lycoming says to do if required but no specific SB.

And then there are those procedures that do not have every detail spelled out. Cleaning parts for example. Sometimes specific chemicals are called and a procedure or two, others, not so much. Your lucky to get clean with Stoddard Solvent.

And isn't this particular procedure just an engine cleaning? Sure it's not what comes to mind for most when they see clean engine in the list of things to accomplish during an annual inspection in 43.13. The procedure SAVVY outlined doesn't really call for anything a Private Pilots isn't allowed to do under 43.13 appendix A. Remove spark plugs, drain oil, change filler. Add a little solvent and swish the rings in it and drain.

I wonder if the Savvy procedure is something Mike came up with or more likely he learned it from a old school mentor of his and he just dared to put it on paper for us to scoff at.

[GAHorn]

While the “flush” system might have some anecdotal success-sorties…. it does NOT have any OEM enging mfr’r support… Therefore it’s an “ad hoc” undocumented and unapproved method of tinkering with your engine…and no matter if it works or not…it’s a questionable practice at best….

If you want to “Un-stick” a ring…the FIRST thing you have to do is determine if you HAVE a stuck ring….and that requires disassembly.

Now that you’ve disassembled it… you have a decision to make…”How do you end up with an Un-stuck ring?”

The OEM solution is inspection/cleaning/repair and/or replacement. The local mechanic solution is to clean it, free it, and re-install it…

(I’ve done the latter quite successfully.) Some folks simply refuse to pull a piston and replace it without new-ring installation … but I’ve cleaned, inspected, re-installed and re-assembled with good results. (i’ve never “flushed” in-in-the-dark and “hoped” for mysterious success…. I insist on actual inspection of the parts before I return it to service.)

I’ve not subscribed to any “savvy mechanic”, ad-hoc methods which “smack” of shade-tree wishful magic with which I could not look a widow in the eye and back-up my work product. (such as: “Oh yeah…. I poured some magic-sauce in it…turned it over…and told your husband it was good enough to take your grandkids aloft with!”) …alternative: “I took it apart and found a stuck ring… freed it up by cleaning, inspected and found it in good condition and reinstalled it, ran the engine and found the defect has been corrected.”

The bottom line is… “Are YOU willing to accurately describe the ad-hoc/“savvy” method and sign your name to it?” … or would you be more comfortable doing the work in an approved manner the engine mfr’r would support…??

[voorheesh]

Is there a written procedure for everything a mechanic does. In theory the FAA correct answer would be yes. But in the real world I'm not so sure we make theory 100 percent reality. Yes, there are a lot of documented procedures from all sorts of sources. So many in fact that a mechanic could be following one and not know the document exists but his procedure is what he was taught. And then there is mixing of procedures between manufacturers products. For example did you know Lycoming has a SB that describes "the rope trick" and it is used in conjunction with a "wobble" test of valve stem to valve guide clearance on ALL Lycoming engines. They also describe how to properly ream a guide and the clearance it should have. Continental s got nothing. That's right no written procedure I've ever found. Is it because Continental valves and valve guide clearance never gets too tight? No, in fact I'd say Continental engines 0300 and smaller have a worse problem than Lycoming when run on 100ll. Yes you can look in a Continental overhaul manual and find all the information you need to measure and ream guides like Lycoming says to do if required but no specific SB.

And then there are those procedures that do not have every detail spelled out. Cleaning parts for example. Sometimes specific chemicals are called and a procedure or two, others, not so much. Your lucky to get clean with Stoddard Solvent.

And isn't this particular procedure just an engine cleaning? Sure it's not what comes to mind for most when they see clean engine in the list of things to accomplish during an annual inspection in 43.13. The procedure SAVVY outlined doesn't really call for anything a Private Pilots isn't allowed to do under 43.13 appendix A. Remove spark plugs, drain oil, change filler. Add a little solvent and swish the rings in it and drain.

I wonder if the Savvy procedure is something Mike came up with or more likely he learned it from a old school mentor of his and he just dared to put it on paper for us to scoff at.

Air carriers and (most) repair stations do have written procedures for every maintenance task in part due to rigid government requirements, but equally due to their being organizations that manage people and outcomes. They cannot simply rely on the ingenuity and resourcefulness of individual employees. They need written policy and procedures. Not to mention, Quality Assurance, Risk Management, and other internal safety assurance. Failure is not an option.

In the case of independent shops and individual mechanics there is much more leeway (freedom) and much less FAA oversight. How often does an inspector observe general aviation maintenance or audit records? Regulations such as Part 43 provide a reliable path to consistent outcomes by requiring procedures and methods that have been validated. Much is left to manufacturers and type certificate holders (and their FAA overseers) for how much or how little written guidance is provided in specific cases. General aviation is fortunate to have experienced technicians and mentors who possess ingenuity and resourcefulness, but who are smart enough to stay within limits. Wouldn’t most agree the system works pretty well at our level?

I have met and corresponded with Mike Busch and have respect for his approach up to a point. I worry that he may sometimes undermine the judgment of IA’s in his zeal to manage or represent owners. (He hates to remove cylinders, for example). He has a significant following and the support if not endorsement from AOPA. I have no personal knowledge of how he would explain or defend the legality of any SAVVY procedure, but it would be interesting to hear his side of this question. Knowing him I’m sure he would expound.

[GAHorn]

I’d like to further point out that the “savvy” method actually creates a “Hydraulic-Lock” condition…. which is universally known to be hazardous to engine health. In fairness, Mr. Busch points out to “carefully” rotate the engine in that condition to “force” the solvent thru the piston rings to hopefully clean/free them up. …but it places the engine at-risk if it’s mishandled. (We had personal experience of what can happen at the State flight dept I worked at when, due to a known hyd-lock on that engine, which the mx-chief pronounced unimportant, one of the pilots subsequently blew a cylinder-head out through the side of the cowling during climb-out in IFR conditions. He was lucky to get it on the ground and could not taxi off the runway when he finally did. I could tell more details but it would distract from this discussion.)

(I doubt that the savvy-procedure actually does what the imagination hopes-for. I imagine it merely dislodges any minute particles and relocates them elsewhere…. As to whether or not it will “free” a stuck ring..? I doubt it. But it should be obvious that whatever it does …. is NOT actually inspected or confirmed the desired results to have occurred. The only thing we can positively know is that we’ve done something that the mfr’r has no knowledge of or to have approved…. and we don’t know what down-sides exist…other that what Mr. Busch alludes to that it may create a fire-hazard in the exhaust.

(How does anyone know if or how much solvent gets past the presumedly-closed exhaust valve..?? AND, how do we know what that magic-solvent did to the valve stems, guides,…other than to wash-out whatever residual lubricant normally resides there..? If Mr. Busch imagines the solvent goes only thru the piston rings…. why does he not imagine that a cylinder full of solvent also pushes solvent past valves and valve-guides…into the exhaust system?)


There are a Lot of “old-mechanics’ tricks we’ve heard of that have a reputation for success. Only time will prove if this “savvy” method has virtue or not…and that would depend on how many people actually use the “savvy” method and document (admit) it over time so the rest of us can have faith in it.

I don’t plan to ever do it.

[dstates]

There are a Lot of “old-mechanics’ tricks we’ve heard of that have a reputation for success. Only time will prove if this “savvy” method has virtue or not…and that would depend on how many people actually use the “savvy” method and document (admit) it over time so the rest of us can have faith in it.

I don’t plan to ever do it.

You don't have too... It helped my condition and I would do it again if the need is there. It was simple and straightforward. I worked with my A&P w/ IA through this. My only recommendation is that each aircraft owner review what is being done to their engine and make sure they are comfortable.

[Bruce Fenstermacher]

Doug, Savvy states:

10. If you can hear the solvent mixture squirting freely into the crankcase, the oil
control ring is clear. If the propeller is difficult to turn and you cannot hear the
solvent mixture squirting into the crankcase, repeat steps 5 through 9 with
additional solvent. You may need to repeat this 3 to 4 times to clear sludge
buildup. YOU WILL BE ABLE TO HEAR AND FEEL WHEN THE RING IS CLEAR.

So Doug, when you did this procedure, how many times did you repeat the procedure? Could you hear the mixture squirting freely and thus the ring clear (or clearer) as the instruction states?

Thanks

[dstates]

Doug, Savvy states:

10. If you can hear the solvent mixture squirting freely into the crankcase, the oil
control ring is clear. If the propeller is difficult to turn and you cannot hear the
solvent mixture squirting into the crankcase, repeat steps 5 through 9 with
additional solvent. You may need to repeat this 3 to 4 times to clear sludge
buildup. YOU WILL BE ABLE TO HEAR AND FEEL WHEN THE RING IS CLEAR.

So Doug, when you did this procedure, how many times did you repeat the procedure? Could you hear the mixture squirting freely and thus the ring clear (or clearer) as the instruction states?

Thanks

Bruce,

We could hear it passing into the crankcase and it came out of the sump drain. Since we made a decent batch of the solvent mixture we went ahead and filled the cylinder about 6 times because once you do it one time we figured we were committed on cleaning everything out. We did our best to keep it out of the exhaust, but we did get some in there. After using compressed air to blow out what we could we took a heat gun to the exhaust and that helped clear out what was left (made some smoke). We also didn't try to start the engine the same day.

Do I know the exact amount it cleaned those rings, no. But I do know that it helped with the compression. We did document it in the logbook as well.

[Bruce Fenstermacher]

Thanks Doug, very interesting.

[GAHorn]

OK…so here’s a scenario: In another thread I posted pics of what I found when I removed the #3 cylinder and piston after a 40 psi compression test.
(broken piston land between the top and 2nd ring) viewtopic.php?f=24&t=16532&hilit=broken+piston+land

The low compression on #3 was strongly indicative of a stuck/frozen ring. I was certain that was what I’d find…due to the smooth-running engine, yet the 40 psi low compression and the sound of escaping air via the crankcase/oil-filler cap.

If I’d tried the “flush” method… it might have provided some relief of increased compression sufficient to encourage me to go ahead and operate the airplane…. And the next trip was from central Tx for 14-hours flying to this years’ convention at Sault Ste Marie, MI….then on to Oshkosh, WI…then all the way back home again…. IF…. IF…it all held together that long (22+ hrs of flying) …and IF it didn’t drop a big chunk of metal from that failing piston into the sump and force us down somewhere survivable. THAT is what I believe a “savvy-flush” might (probably) have resulted.

The only problem then might be …(assuming we survived the emergency off-airport landing and investigation)….getting it out of a clearing and all the way to a shop somewhere willing to work on a “drop-in” problem… OR to get it all the way back home again on a trailer …for that expensive repair.

Instead…. we pulled the cylinder, found the Real problem…not the one to which our imaginations might prefer to lead us….. and performed a simple cylinder assembly replacement and which resulted in a reliable, happy, and Legal repair. A couple weeks later…having made that long round-trip successfully….We’ve made another….today (labor-day weekend)…now in Bruce’s birthplace, Carlisle, PA after another 14 hour/two-day trip… we’re visiting with the 2 yr old grand daughter, daughter and SIL and having a safe and happy trip.
We will leave PA and return to TX next Wed/Thu with the comforting knowledge that low compression cylinder was correctly repaired.

Is this example a clarifying reason to make repairs in the “approved” method rather than the shade-tree method?

I hope so.

Area of missing/broken ring-land. Notice how much the ring actually “flexed” and eating into the piston “crown”.