Breaking in a Freshly Overhauled Continental o-470R

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JoseCuervo

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JoseCuervo
Planning ahead, for the next week, (or two, or three) for when my engine gets stuck back together and mounted in the airplane.

How does one break-in the freshly rebuilt engine? From an operating standpoint? And an oil change standpoint?
 
Dont baby it.

Run it at high RPM's no less than 75% power. The main goal is to get the piston rings fully seated into the cylinder walls.

Your mechanic or whoever did the OH should provide a run-down for a healthy break-in.
 
Ryanb said:
Dont baby it.

Run it at high RPM's no less than 75% power. The main goal is to get the piston rings fully seated into the cylinder walls.
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I'd actually run a little lower rpm and higher manifold pressure, if possible, to get your power. Higher firing pressure should promote ring seating a bit better than making power via rpm.
 
mondtster said:
I'd actually run a little lower rpm and higher manifold pressure, if possible, to get your power. Higher firing pressure should promote ring seating a bit better than making power via rpm.
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However you can make 75%+ continuous power.
 
JoseCuervo said:
Planning ahead, for the next week, (or two, or three) for when my engine gets stuck back together and mounted in the airplane.

How does one break-in the freshly rebuilt engine? From an operating standpoint? And an oil change standpoint?
Click to expand...
Drive it with both feet flat on the floor. Oh, wait, that is for a Detroit Diesel. Nevermind.
 
Clark1961 said:
Drive it with both feet flat on the floor. Oh, wait, that is for a Detroit Diesel. Nevermind.
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12V92: Worst aircraft engine ever.

Whatever the manufacturer recommends. Usually 100% max continuous (or as close as possible) for 30 minutes, then 75% or higher until the rings seat, usually first 10-25 hours.
 
Ted DuPuis said:
12V92: Worst aircraft engine ever.
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There would be a nice oily haze wherever the aircraft went...

A long time ago in a galaxy far away we had one rig with turbo 16V92s for primary power. The crew called them disposable engines. They didn't rebuild them they just replaced'em every now and then....and replacing required cutting a big-assed hole in the deck...
At least with the Cat's and EMDs rebuilding was generally possible.
 
Clark1961 said:
There would be a nice oily haze wherever the aircraft went...

A long time ago in a galaxy far away we had one rig with turbo 16V92s for primary power. The crew called them disposable engines. They didn't rebuild them they just replaced'em every now and then....and replacing required cutting a big-assed hole in the deck...
At least with the Cat's and EMDs rebuilding was generally possible.
Click to expand...

Plus the fact that the engine would make enough power to run a Malibu... and the engine itself would weigh more than a Malibu.

As you may recall from my semi truck thread, the old 2-stroke Detroit Diesels are appealing to me. But not for something that required true dependability.
 
What Ted and Norm said (as usual). (@Ted DuPuis and at @Norman )

Stay low...run it hard.

I use went through this about nine months ago and stayed below 4,000'...ran at a minimum of 23 squared for the first 25 hours. A lot of the time I was running at 23"/2400rpm if temps/altitude allowed it.

It's a nice time of the year in most of the country to break in an engine. Hopefully you're in a part of the country that is cool.
 
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Ted DuPuis said:
12V92: Worst aircraft engine ever.

Whatever the manufacturer recommends. Usually 100% max continuous (or as close as possible) for 30 minutes, then 75% or higher until the rings seat, usually first 10-25 hours.
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Thanks, that helps.
 
Another thing to offer if I may, for each takeoff that you perform during the break-in process, I suggest climbing to altitude over the airport. You can do as you like but I want to get some air under my wings, before leaving the airport vicinity.

Keep in mind, the likelihood for any mechanical abormalities are high at this point in the engine's life. Be vigilant of oil temps and pressure.
 
Broke in an O-540 many years ago. The mechanic wanted zero warm up time on the ground, get it in the air and get airflow going. Started up for a leak check, it was clean. We were at a country airport. No taxi delays. Started, and go, mag check at partial power on takeoff roll then full throttle. It was summer, ground temp above 100F so it was full throttle to get to cooler air, above 10K MSL. Fly out the full fuel tank (3hrs), lean but keep it on the very rich side of peak. Did not have an EGT. Vary the rpm by 100 up and down about every 20 minutes but keep it below redline. Fixed pitch prop, not fuel injected.

Then we put it in service, keep idle time on the ground to a minimum. Full power climb, partial power descents, not idle descents. Change the oil and filter every 25 hrs. After 50hrs changed from mineral oil to AD and 50hr oil changes.

It's been 12 yrs and almost 2000hrs and still going strong.
 
Ryanb said:
Another thing to offer if I may, for each takeoff that you perform during the break-in process, I suggest climbing to altitude over the airport. You can do as you like but I want to get some air under my wings, before leaving the airport vicinity.

Keep in mind, the likelihood for any mechanical abormalities are high at this point in the engine's life. Be vigilant of oil temps and pressure.
Click to expand...

The one guide up above said to use partial power to 40 mph IAS, then full power on initial take off.
Another guide said minimal ground time, do a mag check while rolling.

I will be taking off on a 2300' runway with 50' trees on both ends....

Gonna be busy..... and puckered....
 
Just apply power smoothly. You should always do that anyway. I like to minimize taxiing but when I've had to taxi I do it a little faster than normal and try to not stop and idle. Did your engine get run-in on a stand or on the plane? With that done the initial flight isn't the initial start. You need to be careful with temps but that shouldn't take anything too unusual, just some common sense.
 
JoseCuervo said:
Planning ahead, for the next week, (or two, or three) for when my engine gets stuck back together and mounted in the airplane.

How does one break-in the freshly rebuilt engine? From an operating standpoint? And an oil change standpoint?
Click to expand...
Exactly as the cylinder manufacturer advises.
running it hard is an old wives tale left over from the days of hard stone honing the cylinders. the new finishing of the cylinder bore does not require it.
 
Tom-D said:
running it hard is an old wives tale left over from the days of hard stone honing the cylinders. the new finishing of the cylinder bore does not require it.
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Both of the break-in procedure manuals that Steward provided links to (ECI & TCM) seem to disagree with you. They both recommend high power settings and leaned for best power to maintain "high cylinder combustion pressures."
 
timwinters said:
Both of the break-in procedure manuals that Steward provided links to (ECI & TCM) seem to disagree with you. They both recommend high power settings and leaned for best power to maintain "high cylinder combustion pressures."
Click to expand...
When was the service instruction written, and when did the use of fine honing start? and how do you apply the service instruction to after market cylinders?
 
Tom-D said:
When was the service instruction written
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What difference does it make as to when it was written? Engine design hasn't changed, therefore the method to acheive proper break-in hasn't changed.
 
Here are a few more break-in links. The advice about high cylinder pressures is consistent. If you ever break in an engine with a fixed pitch climb prop you worry about this stuff. With a CS prop just find your 75% power settings and go fly it. It's fun. Enjoy it!

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

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

http://gnaircraft.com/wp-content/uploads/2011/pdfs/breakin.pdf

Whether your engine was overhauled by a big shop that ran it on a stand or a local shop that didn't have a test cell should factor into your initial start. Ask your overhauler about it. He may have a run-in procedure for you to use ahead of your first taxi and flight.

I'm not too far behind you. I'll use a minimum taxi, full power take-off, 75%+ power, etc. My airplane will be brand new so temp management will dictate the flight. I may need to abbreviate a flight to make adjustments to adjust temps. My oil will be Phillips X/C, no additives, change oil and filter at 10 and 25 hours, etc. I can't wait!
 
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Ryanb said:
What difference does it make as to when it was written? Engine design hasn't changed, therefore the method to acheive proper break-in hasn't changed.
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the instruction was written prior to the change in honing requirements. and never brought up to date.
The Engine design has not changed, but cylinder manufacture procedures have. We no longer have cylinder bores that have deep scratches, they are nearly polished with a fine hone, this allows the rings to seat by the time you reach the other end of the runway. or the test cell run is complete.
with these cylinders you can operate the engine normally from day one on multi weight ashless dispersant oil.
time and procedure change SBs and old wives tales don't.
You guys run them anyway you want, we A&Ps need the work.
 
If cylinder honing and rings have improved, and they have, you still use the identical break-in procedures but may see ring seating sooner than expected. That's a good thing. That doesn't change the routine or the mfg recommendations to run it hard and avoid touch and goes, deep prop cycling, etc for the specified break-in duration.
 
Stewartb said:
If cylinder honing and rings have improved, and they have, you still use the identical break-in procedures but may see ring seating sooner than expected. That's a good thing. That doesn't change the routine or the mfg recommendations to run it hard and avoid touch and goes, deep prop cycling, etc for the specified break-in duration.
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When they are already broken in why add to the wear by running hard?
Lots of readers here should read this again and again until they understand.

http://eci.aero/pdf/BreakInInstructions.pdf

I have over 50 sets of these cylinders in service and none used a quart of oil from day one to first oil change, and all didn't use a qt. between oil changes until they were past 500 hours.

Yep you guys run them hard and place a bunch of wear on them that is unnecessary
 
Stewartb said:
I'm not too far behind you. I'll use a minimum taxi, full power take-off, 75%+ power, etc. My airplane will be brand new so temp management will dictate the flight. I may need to abbreviate a flight to make adjustments to adjust temps. My oil will be Phillips X/C, no additives, change oil and filter at 10 and 25 hours, etc. I can't wait!
Click to expand...

The only thing I'll add to that is that I changed my oil and cut the filter after one hour to make sure things weren't coming apart. I really didn't want to wait for 10 hours in case something was screwed up.
 
Continental has a service bulletin that tells you how to do it. Why not follow it. Roughly it goes: keep it at best power or richer, Keep the temperatures down in the climb early on, other than that run at 75% for the first hour and thereafter alternate between 65 and 75 until broken in (oil consumption stabilizes).
 
flyingron said:
Continental has a service bulletin that tells you how to do it. Why not follow it. Roughly it goes: keep it at best power or richer, Keep the temperatures down in the climb early on, other than that run at 75% for the first hour and thereafter alternate between 65 and 75 until broken in (oil consumption stabilizes).
Click to expand...

That's pretty much what everyone's been saying. Conti says 15 hours or so, ECI says 50 hours. So, I guess it just depends on which cylinders he has.

Another consideration is what the overhaul shop says. They are the ones who will be on the front line if there's a warranty issue. My overhaul shop's recommendations were very similar to ECI's.

Edit: in fact, I just went back and looked and his break-in instructions were ECI's with add'l oil changes (1 hour, 8 hours, 16 hours, 25 hours).
 
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Not exactly. TCM's break-in advice is for TCM overhauled engines that spent time on their test stand.

From the TCM instructions I linked earlier....
"Your engine was operated on a factory test cell before leaving Teledyne Continental Motors. However, complete ring seating has not occurred and must be accomplished during the first 25 hours of engine operation after installation."
 
Ideally you have an engine monitor for all cylinders. If you have that, you run it low altitude and fast until you see the cylinder temps drop and stabilize, usually in the first few hours. Agree with others, stay in easy glide range of an airport for the first hour or so, and don't futz around before the first takeoff - do the engine checks "on the run" while you're taxiing out. If you're at a towered field, call the tower ahead of time to tell them you have a new engine break in and really need a no-delay takeoff clearance if they can possibly work it out.
 
Tom-D said:
the instruction was written prior to the change in honing requirements. and never brought up to date.
The Engine design has not changed, but cylinder manufacture procedures have. We no longer have cylinder bores that have deep scratches, they are nearly polished with a fine hone, this allows the rings to seat by the time you reach the other end of the runway. or the test cell run is complete.
with these cylinders you can operate the engine normally from day one on multi weight ashless dispersant oil.
time and procedure change SBs and old wives tales don't.
You guys run them anyway you want, we A&Ps need the work.
Click to expand...

Got some hard data to back that up?
 
Stewartb said:
Here are a few more break-in links. The advice about high cylinder pressures is consistent. If you ever break in an engine with a fixed pitch climb prop you worry about this stuff. With a CS prop just find your 75% power settings and go fly it. It's fun. Enjoy it!

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

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

http://gnaircraft.com/wp-content/uploads/2011/pdfs/breakin.pdf

Whether your engine was overhauled by a big shop that ran it on a stand or a local shop that didn't have a test cell should factor into your initial start. Ask your overhauler about it. He may have a run-in procedure for you to use ahead of your first taxi and flight.

I'm not too far behind you. I'll use a minimum taxi, full power take-off, 75%+ power, etc. My airplane will be brand new so temp management will dictate the flight. I may need to abbreviate a flight to make adjustments to adjust temps. My oil will be Phillips X/C, no additives, change oil and filter at 10 and 25 hours, etc. I can't wait!
Click to expand...

My "minimum taxi" will be about 200 feet from the shop hangar to the runway end, assuming prevailing winds. Otherwise, it will be 2100' to the far end of the runway.

I assume I need some heat in the oil before full take-off power. Not sure how I get that in 200'.
 
Tom-D said:
the instruction was written prior to the change in honing requirements. and never brought up to date.
The Engine design has not changed, but cylinder manufacture procedures have. We no longer have cylinder bores that have deep scratches, they are nearly polished with a fine hone, this allows the rings to seat by the time you reach the other end of the runway. or the test cell run is complete.
with these cylinders you can operate the engine normally from day one on multi weight ashless dispersant oil.
time and procedure change SBs and old wives tales don't.
You guys run them anyway you want, we A&Ps need the work.
Click to expand...


What about MoGas??

I think I likely have 25 gallons of Mogas in the wings.

Should I drain it and replace it with 100LL? Or just add 25 gallons of 100LL, then top it off (80 gallons) with 100LL after the first hour, and when I get to an airport with fuel pumps?
 
timwinters said:
Both of the break-in procedure manuals that Steward provided links to (ECI & TCM) seem to disagree with you. They both recommend high power settings and leaned for best power to maintain "high cylinder combustion pressures."
Click to expand...

I always lean for taxi, then lean for take-off. Assume "leaned for best power" is same as leaning as required, rich of peak?
 
timwinters said:
The only thing I'll add to that is that I changed my oil and cut the filter after one hour to make sure things weren't coming apart. I really didn't want to wait for 10 hours in case something was screwed up.
Click to expand...

I kind of like that idea.
 
JoseCuervo said:
What about MoGas??

I think I likely have 25 gallons of Mogas in the wings.

Should I drain it and replace it with 100LL? Or just add 25 gallons of 100LL, then top it off (80 gallons) with 100LL after the first hour, and when I get to an airport with fuel pumps?
Click to expand...

When I've been in that position I've done it like you propose. Put as much 100LL in as you can, then keep adding more after every flight. Eventually you'll have all the mogas out of the system and you can run that way until the end of the specified break in period where you're supposed to be running 100LL.

If the tanks were completely full of mogas I'd be draining at least some or all of it but when they're at or below half tanks I haven't worried about it too much.

I'm curious to see how the break in instructions and possibly materials used will change when leaded fuel is no longer available.
 
JoseCuervo said:
What about MoGas??

I think I likely have 25 gallons of Mogas in the wings.

Should I drain it and replace it with 100LL? Or just add 25 gallons of 100LL, then top it off (80 gallons) with 100LL after the first hour, and when I get to an airport with fuel pumps?
Click to expand...

I wouldn't worry about it at all. I've taken virgin engines and run them on MoGas without impact, although admittedly I didn't run more than 100-200 hours on them. Just top off with 100LL and you'll be fine.
 
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