Possible to tell if the engine was broken in properly?

[MountainDude]

If I find a plane with a very new engine (less than 50 hrs):
1. Is there a way to tell whether the engine was broken in properly?
2. If it was not broken in properly, what are the long-term ownership consequences?

Thank you

 

[Stewartb]

Properly- high compression and low oil use.
Improper- low compression and high oil use.

 

[Tom-D]

Sure there is,, How much oil is it using?

consequence?? long term high oil consumption.

 

[MountainDude]

Properly- high compression and low oil use.
Improper- low compression and high oil use.

Thank you. We can check for compression during a pre-buy. How would we check for oil usage?

 

[Tom-D]

The question should say which type of cylinder finish the cylinder has..

regular steel cylinder with chrome rings
regular steel cylinder with cast iron rings.
Nichrome with cast iron rings,
chrome rebuilt cylinders with cast iron rings.

 

[Tom-D]

Thank you. We can check for compression during a pre-buy. How would we check for oil usage?

Usage oil used over time.

How new?
Is it smoking? blue smoke with that burned oil smell?

 

[Stewartb]

Thank you. We can check for compression during a pre-buy. How would we check for oil usage?

Buying an airplane isn't without risk. Do your inspections and make your decision, but once the money changes hands you own it. That's how it works for all of us.

With a low time engine and good compressions with known oil in the crankcase? Oil consumption isn't a big concern.

 

[Tom-D]

With the new era new cylinders it is most impossible to not break in cylinder.

The rings will be seated by the time you get to pattern altitude, and high oil consumption will never occur.

 

[JOhnH]

With the new era new cylinders it is most impossible to not break in cylinder.

The rings will be seated by the time you get to pattern altitude, and high oil consumption will never occur.

I don't mean to sound ignorant, even if I am, but what are new era new cylinders? Is that a brand name? A type? Or just a description of modern cylinders? I couldn't find anything using that as a search term.

 

[Tom-D]

I don't mean to sound ignorant, even if I am, but what are new era new cylinders? Is that a brand name? A type? Or just a description of modern cylinders? I couldn't find anything using that as a search term.

There ya go, cylinders like superior, ECI, or resent manufactured TCM. they have a very smooth finish.
see the picture
No more 30 degree cross hatching. They break in right now.

 

[bkspero]

What about Lycoming steel, Tom? Chrome rings. How quickly do they break in?

 

[Cap'n Jack]

There ya go, cylinders like superior, ECI, or resent manufactured TCM. they have a very smooth finish.
see the picture
No more 30 degree cross hatching. They break in right now.

If they are so smooth, what holds the oil in place?

When the forged steel barrel is initially machined at the factory, it comes out of the computer numeric control machine with a mirror-smooth interior finish. This won’t do, because it’s impossible to coat a mirror-smooth steel surface with a thin film of oil. If you try, the oil beads up into discrete droplets, much in the way that water beads up when applied to a freshly waxed surface. Engineers say that the mirror-smooth steel surface is not “oil-wettable.”

The need for break-in

To make the barrel oil-wettable, its surface must be roughened very slightly. This is accomplished by finishing the inside surface of the barrel with a special honing tool that uses very hard, 220-grit stones to create a crosshatch pattern of tiny scratches—a so-called microfinish, because the scratches are typically about 30 microinches (0.000030”) deep. This crosshatch pattern provides just enough surface roughness to make the barrel oil-wettable.

https://www.aopa.org/news-and-media/all-news/2019/january/pilot/savvy-maintenance-breaking-good

 

[Tom-D]

What about Lycoming steel, Tom? Chrome rings. How quickly do they break in?

I've little experience with Lycoming.

 

[Tom-D]

If they are so smooth, what holds the oil in place?

Why does it require heavy deep scratches to do that?
I don't have the answer for your question. but the after market cylinders work, or they wouldn't have 99% of the market.

 

[Cap'n Jack]

Why does it require heavy deep scratches to do that?
I don't have the answer for your question. but the after market cylinders work, or they wouldn't have 99% of the market.

I was never under the impression that the scratches needed to be "heavy or deep", especially since the reference cited indicated flattening the peaks was the reason for break-in.

I appreciate the rest of your reply.
Edit- perhaps you should have stopped here, instead of making the post below.

 

[Tom-D]

https://www.aopa.org/news-and-media/all-news/2019/january/pilot/savvy-maintenance-breaking-good

No new thinking in 100 years, old methods die hard. all because there are those out there that rebuild cylinders the old fashion way.

 

[Tom-D]

I was never under the impression that the scratches needed to be "heavy or deep", especially since the reference cited indicated flattening the peaks was the reason for break-in.

Now there are no peaks to flatten.
did you realize that the scratch will fill with hard carbon before the oil consumption will stop?
that's why the old way of thinking plans on 50 hours break in time.

 

[timwinters]

With the new era new cylinders it is most impossible to not break in cylinder.

The rings will be seated by the time you get to pattern altitude, and high oil consumption will never occur.

Oh, jeeeeeezus.

How do you reconcile what you stated above with this entire thread of yours:

https://www.pilotsofamerica.com/community/threads/cfis-vs-maintenance.117532/

Which, BTW, you started with:

The engine was a 0 since major (not by me) and the owner was given specific instruction for break in for the 6 brand new superior cylinders, by the engine overhaul company a Certified repair station with a good reputation.
The CFI ignored these instructions, and now 52 hours since major the cylinders are toast, compression is down to 20/80 and burning 1 qt in 3 hours, (no leaks)
The CFI admitted he was told how the company wanted the engine to be run for the first 50 hours. and he admitted he did not run it that way..

 

[Cap'n Jack]

No new thinking in 100 years, old methods die hard. all because there are those out there that rebuild cylinders the old fashion way.

I really don't see much of a difference, other than detail, between the AOPA information that you don't like, and the Superior cylinders which are supposed to have reduced break-in time

https://www.aopa.org/news-and-media/all-news/2019/january/pilot/savvy-maintenance-breaking-good

To accomplish this, we need to run the engine hard for the first hour or two—hard enough to create greater-than-normal pressure on the compression rings. The semi-trapezoidal design of the compression rings uses combustion chamber pressure to force the rings tightly against the barrel walls. Break-in demands that this pressure be maximized to provide enough force to breach the oil film.

https://www.superiorairparts.com/downloads/serviceletters/L96-08.pdf

BREAK-IN FLIGHT OPERATION:
• Perform normal pre-flight and run-up in accordance with engine operator’s manual (remember: only cycle prop to a 100 RPM drop if you have a controllable pitch propeller). Keep ground runs to a minimum.
• Conduct normal take-off at full power, full rich mixture, to a safe altitude. • Maintain a shallow climb at full power. Use caution to avoid overheating the cylinders. Should overheating occur, reduce power and adjust mixture appropriately. Refer to Pilot’s Operating Handbook for specific procedures and temperatures including leaning to a fuel flow meter or leaning without EGT or fuel flow meters.
• Monitor RPM, oil pressure, oil temperature & cylinder temperature.
• During the first hour of operation, maintain level flight at 75% power. Vary the power setting every 15 minutes during the second hour between 65-75%.
• Avoid long descents at cruise RPM and low manifold pressure (could cause ring flutter).
• After landing, check again for any fuel and/or oil leaks, or other discrepancies, and repair.
• Continue flying at 65-75% power with mixture adjusted to approximately 75°F rich of peak EGT on subsequent flights until rings have seated, oil consumption stabilizes, and cylinder head temperatures drop. This is a sign that the cylinders are broken in. Refer to Pilots Operating Handbook for leaning with fuel a flow meter or leaning without fuel flow or EGT meters.
• After break-in, oil may be changed to ashless dispersent of the proper grade.
• At no time should cylinder head temperature be allowed to exceed original airframe equipment manufacturer recommended maximum cruise limit.

With the new era new cylinders it is most impossible to not break in cylinder.

The rings will be seated by the time you get to pattern altitude, and high oil consumption will never occur.

The Superior information above suggests otherwise. Likewise for the ECi procedure (http://11hc.44rf.com/manuals/engine-prop/eci/ECi---break_in_instructions_&_oil_mgt.pdf )

Why the discrepancy?

 

[Cap'n Jack]

Now there are no peaks to flatten.
did you realize that the scratch will fill with hard carbon before the oil consumption will stop?
that's why the old way of thinking plans on 50 hours break in time.

Actually, the post above (#19) mentions ECi, their link mentions 25 hours.
AOPA didn't say 50 hours. I was under the impression that if I manged filled those grooves and scratches with carbon, it was called "glazing" and the cylinder needed to be rehoned, and the rings replaced, essentially a top overhaul.

 

[Tom-D]

How do you reconcile what you stated above with this entire thread of yours:

Easy we never did find the cause of the failure, he never came back and said.

 

[Cap'n Jack]

Easy we never did find the cause of the failure, he never came back and said.

By this statement below.....

With the new era new cylinders it is most impossible to not break in cylinder.

The rings will be seated by the time you get to pattern altitude, and high oil consumption will never occur.

....break-in shouldn't have mattered.

 

[Tom-D]

Actually, the post above (#19) mentions ECi, their link mentions 25 hours.
AOPA didn't say 50 hours. I was under the impression that if I manged filled those grooves and scratches with carbon, it was called "glazing" and the cylinder needed to be rehoned, and the rings replaced, essentially a top overhaul.

Do you believe the operator has any control over if the scratches fill or not?
OBTW the scratches filling with carbon has nothing to do with glazing of the cylinder wall.

 

[Tom-D]

By this statement below.....

....break-in shouldn't have mattered.

Right , but over heating will cause his symptoms. and that has a lot to do with break-in

 

[Tom-D]

I manged filled those grooves and scratches with carbon, it was called "glazing" and the cylinder needed to be rehoned, and the rings replaced, essentially a top overhaul.

Glazing happens when a cylinder is overheated and the rings loose their temper, when this happens the rings loose their ability to scrape off excess oil from the cylinder wall, which gets burned into a layer of hard carbon.
and yes it must be removed and new rings installed

 

[Cap'n Jack]

Do you believe the operator has any control over if the scratches fill or not?
OBTW the scratches filling with carbon has nothing to do with glazing of the cylinder wall.

Yes, I do think the operator has a great deal of control over glazing.

As for the scratches filling with carbon, that is described as "glazing":
https://www.aopa.org/news-and-media/all-news/2019/january/pilot/savvy-maintenance-breaking-good

The reason for all this is that running a freshly honed cylinder at low power for any significant length of time can cause a condition known as glazing, in which a tough residue of carbonized oil builds up on the cylinder walls and stops the break-in process dead in its tracks. Once the cylinder has become glazed, it’s no longer oil-wettable, and the only solution may be to remove and re-hone the cylinder and start the break-in process all over again.

Right , but over heating will cause his symptoms. and that has a lot to do with break-in

This still contradicts this statement:

With the new era new cylinders it is most impossible to not break in cylinder.

The rings will be seated by the time you get to pattern altitude, and high oil consumption will never occur.

It only takes a few minutes at most to get to pattern altitude in any plane I've flown.

 

[Cap'n Jack]

Glazing happens when a cylinder is overheated and the rings loose their temper, when this happens the rings loose their ability to scrape off excess oil from the cylinder wall, which gets burned into a layer of hard carbon.
and yes it must be removed and new rings installed

See reply above, post # 26

 

[Tom-D]

See reply above, post # 26

I would wager that anyone cooked their cylinders did it before they got airborne. remember low power setting equals low airflow over the cylinders, read post 26 with that in mind.

 

[Cap'n Jack]

I would wager that anyone cooked their cylinders did it before they got airborne

What do you mean by "cooked their cylinders"?

Still, in this thread, you've contradicted both yourself and the manufacturers that you mentioned. The AOPA reference has nothing contradicted by the manufacturers. You should have stopped at post #14.

 

[Tom-D]

The reason for all this is that running a freshly honed cylinder at low power for any significant length of time can cause a condition known as glazing, in which a tough residue of carbonized oil builds up on the cylinder walls and stops the break-in process dead in its tracks

Simply because the temper in the rings is gone and they can't scrape as they should, WHY? they were over heated.

 

[Tom-D]

What do you mean by "cooked their cylinders"?

Still, in this thread, you've contradicted both yourself and the manufacturers that you mentioned. The AOPA reference has nothing contradicted by the manufacturers. You should have stopped at post #14.

You must remember the Manufacturers must do the CYA thing and sell cylinders.
If they came out with a totally new concept what would happen..
same as here no one would believe them.
Old beliefs die hard, but the cross hatching is gone. and it does not harm a new cylinder to run it at high power settings. It just makes the break in happen quicker, with no measurable oil consumption how can you tell when that happened?

 

[Tom-D]

Since early 90s I've installed near 100 after market cylinders none of which burned oil to start, all broke in nearly instantly. both ECI and Superior have the finish I've shown you, So you believe what you want. The cross hatching is gone, that's a fact, and the old way of thinking should have gone with it. But NO you and other will believe what you read like, it is holly Grail.

 

[Cap'n Jack]

The reason for all this is that running a freshly honed cylinder at low power for any significant length of time can cause a condition known as glazing, in which a tough residue of carbonized oil builds up on the cylinder walls and stops the break-in process dead in its tracks

Simply because the temper in the rings is gone and they can't scrape as they should, WHY? they were over heated.

I disagree, the cylinder temperatures don't get high at low power. Temperatures can get high at high power, and all the references warn about watching the temperatures as well. They also want the engine to make 75% power during break-in suggesting that a normally-aspirated engine shouldn't flown so high it can't produce that power- it's cooler up there!

The first flight should be at least one hour in duration; climb speeds should be kept high when practical and leaning in climb avoided except as necessary to maintain smooth operation at high altitudes and lean to best power. Cruise settings should be maintained at 75% power or more whenever possible. Any sort of abusive operation such as touch and goes, power off stalls, and 0 thrust should be avoided for the first 30 hours

https://www.pennyanaero.com/aircraft-engine-break-in-instructions

Here's why the glaze forms:

Avoid long, low power descents as, again, there will be insufficient cylinder pressure force the piston rings out to form a gas seal and you will suffer from large amounts of combustion blow-by past the rings and also large amounts oil not being scraped from the cylinder wall. This combination can lead to excessive oil burn that can inhibit ring seating.

https://www.shell.com/business-cust...centre/technical-talk/techart08-30071255.html

You must remember the Manufacturers must do the CYA thing and sell cylinders.
If they came out with a totally new concept what would happen..
same as here no one would believe them.
Old beliefs die hard, but the cross hatching is gone. and it does not harm a new cylinder to run it at high power settings. It just makes the break in happen quicker, with no measurable oil consumption how can you tell when that happened?

If the cross-hatching is gone, what hold the oil in place in the cylinder? A smooth surface doesn't hold oil well.

Since you tried to convince us ammonia was an acid, I don't simply trust your statements anymore.

How do you know when you have broken the engine in?

There are several clues that the engine will give you, and one key one is oil consumption, so you should really start to take note what the consumption is from the start. What you will find is that the consumption will probably be quite high initially, will reduce rapidly and then plateau at a certain value.

What this value is is not really too important - it can be anywhere in the range of 1 litre every 4 to 20 hours - an indication of stabilisation is more the key. Too high an oil consumption indicates that the engine has not broken in yet (or has possibly glazed if it is over 100 hours operation).

Second indication to look out for is the exhaust stack. This will normally start being black and wet (due to the high level of oil burned during the initial stages of break-in). It will then turn to black soot and finally produce a tan / grey deposit, indicating that there is little oil being burned and the mixture setting is correct.

Another indication is that of crankcase pressurisation. If you fill the engine up to the maximum oil level indication and it rapidly loses the first half litre down the breather pipe then many people just fill the engine with less oil next time. This is fine if it is an old, worn engine, but during break-in it is actually telling you something.

Assuming that it is not an aerobatic engine, the reason that the oil is being pushed down the breather is that the crankcase is being over-pressurised by exhaust gas getting past the ring pack. In other words, the engine is not effectively sealing itself and has not achieved a good gas seal between rings and bore – so the break-in process is not yet complete.

https://www.shell.com/business-cust...centre/technical-talk/techart08-30071255.html

 

[Cap'n Jack]

Since early 90s I've installed near 100 after market cylinders none of which burned oil to start, all broke in nearly instantly. both ECI and Superior have the finish I've shown you, So you believe what you want. The cross hatching is gone, that's a fact, and the old way of thinking should have gone with it. But NO you and other will believe what you read like, it is holly Grail.

Tom, why should anyone here believe you? After all, you claimed ammonia was an acid. Just because you say it doesn't make it so. Every single reference cited indicates there is a pattern to hold the oil. You only cited...yourself

When a cylinder is manufactured, a cross-hatch hone is used to score a diamond pattern into the surface of the liner; this is necessary to allow an oil film to be held on the surface of the cylinder wall and lubricate the piston during operation.

https://www.shell.com/business-cust...centre/technical-talk/techart08-30071255.html

 

[Tom-D]

Why should anyone believe the old rhetoric when the manufacturing has changed?
OBTW, I'm not a chemist, I am an A&P-IA, I'm not good at math either. so I have a calculator.

Here is a picture of a Chrome Cylinder, Do you believe the standard practice should be used on its break-in?

 

[Stewartb]

Because the manufacturer’s break-in instructions haven’t? They’re very specific.

 

[Tom-D]

Because the manufacturer’s break-in instructions haven’t? They’re very specific.

And why haven't they changed?

 

[Stewartb]

because they know their product better than you?

 

[Tom-D]

because they know their product better than you?

And they got lawyers, and a reason to CYA

 

[Stewartb]

And engineers, too. And you have no skin in the game. That math is easy to figure.