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FIRST FLIGHT POWER SETTINGS

Lizard Lips

Active Member
Passed my Airworthiness inspection Monday and plan to make the first flight of my RV-14A Saturday. Installed is a factory new Lycoming IO-390. The first few flights will consist of exploring the envelope of the airplane and getting the feel of it's flight characteristics. What power settings would you guys suggest for a new engine during the first few hours? I had thought maybe 2300 rpm/23 "Hg manifold pressure or maybe 2400/24. During this break-in period should the engine be run "hard" or should it be run at low power settings? Your opinions are appreciated.

Joe
Longview, Texas

RV-14A Certified Airworthy and ready to go
Arion Lightning LS-1 Flown regularly
2020 dues paid
 
Congratulations

Passed my Airworthiness inspection Monday and plan to make the first flight of my RV-14A Saturday.
Joe
Longview, Texas

RV-14A Certified Airworthy and ready to go
Arion Lightning LS-1 Flown regularly
2020 dues paid

Joe----congrats on the pink:D
 
Break in

I would run it exactly as the warranty provider recommends. General and time tested way is run it hard without getting it too hot.

Don Broussard
RV9 Rebuild in Progress
57 Pacer
 
Good one Magnus. Pity your EAA fly-in had to be CoVied, I’d love to have visited and met you again. Though the wx was **** last year...

all the above are good tips.

... to the OP, no need to capitalize us, we read you 5, don’t shout, thanks ;)
 
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I have broken in two engines in rv6’s recently. Both were ground run 5 mins and leaked checked. Ground run 5 mins at max power and leaked checked. I then cowl them up, takeoff at WOT and never pull the power back for the first hour. Land, change oil and leak check. I then takeoff and run WOT for 2.5 hr flights until hitting 5 hrs total at WOT. I then run at least 75% power till 10 hrs and change the oil again. The cht’s will normally drop at 2-3 hrs for steel cylinders and 6-7 hrs for chrome cylinders. The oil use normally stabilize around the 5 hr mark. My engine is running 1 qt in 15 hrs and my buddies engine is running 1qt in 12 hrs on chrome cylinders. I am very happy with how they are performing. Run a new engine at WOT and full rich as long as the cht’s are under control and don’t do pattern work for the first 10 hrs. I keep them on mineral oil for the first 50 hrs and then aeroshell 100w.
 
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For engine break in I would recommend climbing to where you reach 25 inches, full throttle manifold pressure (5000 to 5500 feet), then pull RPM back to 2500-2600 (watch if any RPM prop restrictions) and leave it there while circling the field. Run it full rich or slightly pull back to 1300 +/- EGT. Closely monitor CHT and richen mixture or pull back power if unable to keep under 400-425 degrees. The EGTs should slowly drop.

Run that way for 10 to 15 minutes then, if a first flight, slow down for a quick slow flight/stall check. Go land, uncowl, and inspect.

Next flight run hard again for 10 to 15 minutes before doing some moderate slow flight testing. Again, uncowl and inspect.

This recommendation is for break-in. There are many other important items to be considered on a first flight. Might check some flight test cards and see what others have done. Have fun, but take things seriously.

GM
 
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Do a search on this forum for Mahlon Russell's break in procedures. His posts on the topic are pure gold.

Be aware there are TWO different procedures - one should be very careful not to confuse them.

1) RUN IN - this is done with a brand new engine, just assembled. The procedure for run-in includes some very specific instructions on X RPM for Y minutes. If your engine has been built by a reputable shop, this run-in procedure has almost certainly been done for you in a test cell. New factory Lycoming engines have the run in procedure done at the factory.

2) BREAK IN - this is the next stage in the engine's life where we break in the piston rings against the cylinder walls. This is the one where we want to be running either mineral oil or Phillips XC multi-grade (no other multi-grade oil, no Aeroshell multi-grade, no Cam Guard or similar). We're trying to get the friction between piston rings and cylinder walls to wear the two surfaces to the point of making a good seal. Once this is accomplished, temperatures will drop and oil consumption will stabilize. The best way to achieve this break-in seems to be to run at high power settings (nothing below 75%) while keeping the engine as cool as possible. That means FULL RICH mixture, low climb angles for good cooling airflow and staying over the airport in case something in that new engine isn't quite right. Keep your altitude low as climbing to higher altitude will both prolong low cooling airflow and raise density altitude to the point where getting the desired high power setting may not be possible.

With respect to ground runs, Mahlon's advice on that topic is excellent. In a nutshell, perform ground runs as often as is necessary to ensure all systems are functioning properly. Monitor CHT. NEVER let CHT get above 300 degrees F. Do a ground run, shut down before hitting 300F, let the engine cool to the point where you can comfortably rest your hand on the cylinders for 30 seconds. Only when the engine is this cool is it safe to start up and do another ground run, again to a CHT limit of 300F. This advice is critical for preventing glazing of cylinder walls.

I followed Mahlon's recommendations for ground running and breaking in our factory-new O-360. Temperatures stabilized in the second hour of flight and I could feel the engine was running more freely - it just felt smoother. Oil consumption was very low, less than a quart in the first 10 hours. I cut open the filter after the first flight and was surprised at how little metal was in it. At 10 hours I changed the oil, cut open the filter and again was surprised by the small amount of metal in it. Now, at nearly 200 hours I'm getting 22-23 hours per quart of oil. I'm using Phillips XC oil and am adding Cam Guard in the recommended quantity. I didn't start using Cam Guard until the 50 hour mark.
 
Do a search on this forum for Mahlon Russell's break in procedures. His posts on the topic are pure gold.

Be aware there are TWO different procedures - one should be very careful not to confuse them.

1) RUN IN - this is done with a brand new engine, just assembled. The procedure for run-in includes some very specific instructions on X RPM for Y minutes. If your engine has been built by a reputable shop, this run-in procedure has almost certainly been done for you in a test cell. New factory Lycoming engines have the run in procedure done at the factory.

2) BREAK IN - this is the next stage in the engine's life where we break in the piston rings against the cylinder walls. This is the one where we want to be running either mineral oil or Phillips XC multi-grade (no other multi-grade oil, no Aeroshell multi-grade, no Cam Guard or similar). We're trying to get the friction between piston rings and cylinder walls to wear the two surfaces to the point of making a good seal. Once this is accomplished, temperatures will drop and oil consumption will stabilize. The best way to achieve this break-in seems to be to run at high power settings (nothing below 75%) while keeping the engine as cool as possible. That means FULL RICH mixture, low climb angles for good cooling airflow and staying over the airport in case something in that new engine isn't quite right. Keep your altitude low as climbing to higher altitude will both prolong low cooling airflow and raise density altitude to the point where getting the desired high power setting may not be possible.

With respect to ground runs, Mahlon's advice on that topic is excellent. In a nutshell, perform ground runs as often as is necessary to ensure all systems are functioning properly. Monitor CHT. NEVER let CHT get above 300 degrees F. Do a ground run, shut down before hitting 300F, let the engine cool to the point where you can comfortably rest your hand on the cylinders for 30 seconds. Only when the engine is this cool is it safe to start up and do another ground run, again to a CHT limit of 300F. This advice is critical for preventing glazing of cylinder walls.

I followed Mahlon's recommendations for ground running and breaking in our factory-new O-360. Temperatures stabilized in the second hour of flight and I could feel the engine was running more freely - it just felt smoother. Oil consumption was very low, less than a quart in the first 10 hours. I cut open the filter after the first flight and was surprised at how little metal was in it. At 10 hours I changed the oil, cut open the filter and again was surprised by the small amount of metal in it. Now, at nearly 200 hours I'm getting 22-23 hours per quart of oil. I'm using Phillips XC oil and am adding Cam Guard in the recommended quantity. I didn't start using Cam Guard until the 50 hour mark.

+1! This was my experience as well using the same procedure on my Red Gold Mattituck with nitrided cylinders. At oil change, I put in 7 qts. It fills the filter cannister on engine start and as hours accumulate I add as necessary to keep it at 6 qts on the dip stick until next oil change. Eleven years and 865 hours or so later and compressions are 76/80 or better in all cylinders. Oil consumption is still right around 22-25 hours / quart depending on how hard I run it and if aerobatics are flown.
 
The super short version:

- Run it hard, even above 75% for the first few hours if CHTs stays low enough.

Hard at 75% or above for the first 2 hours is what was recommend by my long time engine builder. I believe that is consistent with Lycoming's break in procedure.
 
I know there are lots of threads on break-in. Instead of starting a new one, i'm reopening this excellent thread.
I have to break-in my O-320 again after an IRAN with replacement cylinders. What makes me nervous is temperature management and how hot i can run it during break-in without damaging it. There was an excellent presentation by Mike Busch at Osh where one of his slides says (for break-in) "keep CHT udner 440F for Lycoming". But in his book "Engines" he repeatedly says that CHTs over 400 should generally be avoided for any length of time and talks about how descrutive they are. So, during the first couple of hours, if I see CHT climbing over 420, what do I do? Do I keep the power up and let the engine run with CHTs as high as 420-440 for extended periods of time? Or do I power-back and keep them under 420 or even down to 400, even if this requires throttling back to 60% or less power? For the first break-in flight, would running at 439F for 15-20 minutes be acceptable, or damanging? I'm running a FP prop, so this may make break-in more difficult.
After just having spent a fortune on my IRAN, I'm really nervous about trashing it on my break-in!
 
I know there are lots of threads on break-in. Instead of starting a new one, i'm reopening this excellent thread.
I have to break-in my O-320 again after an IRAN with replacement cylinders. What makes me nervous is temperature management and how hot i can run it during break-in without damaging it. There was an excellent presentation by Mike Busch at Osh where one of his slides says (for break-in) "keep CHT udner 440F for Lycoming". But in his book "Engines" he repeatedly says that CHTs over 400 should generally be avoided for any length of time and talks about how descrutive they are. So, during the first couple of hours, if I see CHT climbing over 420, what do I do? Do I keep the power up and let the engine run with CHTs as high as 420-440 for extended periods of time? Or do I power-back and keep them under 420 or even down to 400, even if this requires throttling back to 60% or less power? For the first break-in flight, would running at 439F for 15-20 minutes be acceptable, or damanging? I'm running a FP prop, so this may make break-in more difficult.
After just having spent a fortune on my IRAN, I'm really nervous about trashing it on my break-in!

Brand new cylinders will run hot for a couple of hours as the rings and cyl walls break in (this causes excess friction which creates excess heat). Glazing here is the primary concern and believe that glazing starts to happen somewhere around 435-450 prior to ring setting. However, it is barrel temp that dictates glazing and you never really know what the barrel temp is. I would try to keep under 430 or 435. On initial take off, keep taxing to a minimum and use a very shallow climb to altitude, to keep cooling flow high. If CHTs get to 430, pull the power back, cool down and then go back to 75%. Pulling back to 55% for a few minutes is no big deal. Glazed cylinders are a bigger problem.

440 is not going to hurt the cylinders for a few minutes, but you want to avoid glazing at all costs. 400* at 75% + power on brand new cylinders is likely an unrealistic goal in the summer. By new, I mean fresh rings on a freshly honed cylinder.
 
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Run it hard like the book says. When I picked up my S1000RR I asked about breakin, they told me BMW runs them at full power at the factory, if they don't blow up they're good.
 
Break In

The Mahlon Russell protocol for ground runs is 350 CHT limit NOT 300.
For engines that have test cell run in one should still do at least a couple of ground runs to check for leaks etc.
My personal limit for break in flights is 400 degrees CHT. Running at lower power settings does not compromise ring seating, it just extends the time required for ring seating.
I did my first flights on 0 320 non RV in extremely hot weather and only had one momentary excursion above 400 by a small amount. Things that help: If necessary shut down at end of runway and allow temps to cool. Do all the pre takeoff checks. Start the engine and do a quick dead mag check at around 1200 rpm. You should be on the takeoff roll within one minute of second engine start. On the early takeoffs 130 knots and 24" mp worked for me for climb. Setting the timing at 22 degrees helps and I did not notice any significant change in power when I later reset to 25 degrees. Note that some of the angle valve Lycomings use 22 degrees as standard.
THE MAHLON RUSSELL PROCEDURE IS THE GOLD STANDARD. I do not like much of anything about some of the others, especially Mike Busch.
BE SURE TO REMOVE ONE SET OF SPARK PLUGS AND MOTOR THE ENGINE TO GET OIL PRESSURE BEFORE FIRST START.
 
So many...

So many methods.

The best advice is to break it in based on what the manufacturer recommends as they are covering the warranty should something happen.

If you choose to follow the "experts" and do something different, well, what do you think the manufacturer is going to say about the warranty?
 
So many methods.

The best advice is to break it in based on what the manufacturer recommends as they are covering the warranty should something happen.

If you choose to follow the "experts" and do something different, well, what do you think the manufacturer is going to say about the warranty?

Well the manufacturer doesn't list temp limits for break in, beyond the 500 CHT limit and it seems quite unlikely they would process a warranty claim for glazed cylinders, as that is not a manufacturing flaw. Nothing against following mfg recommendations, but in this case there isn't much guidance. I can tell you from personal experience that if the cylinders get too hot, you will have glazing. I got to about 455 for 10-20 seconds on the first flight and glazed 2 cylinders. This is much more critical if the engine is handed to the owner without test stand time, which I suspect is the case here. Most of the heat is gone in 2 hours and many builders run it that long on the test stand, so many have limited experience with this.

Let's remember that Lyc only sells new or reman'ed engines and they all get time on the test stand to get through that high heat period. Therefore no reason for them to discuss this issue much. With field repairs, it is the shops responsibilty to provide guidance.
 
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Run-In vs Break-In

I have to break-in my O-320 again after an IRAN with replacement cylinders.

Here is some info that may be helpful. A new engine from the factory would have been run-in already. An IRAN'd engine with new cylinders probably/maybe not.

Run-In vs Break-In:

Ref: https://www.continental.aero/xPublications/xService Bulletins/Experimental PMA/SIL012/
"III. RUN-IN vs. BREAK-IN

Engine overhaul shops (and new engine manufacturers) typically run-in all engines for a period of one to two hours prior to release for installation in the airframe. However, run-in was never intended to be a complete break-in. The objective of the run-in is to:

1. Verify the engine meets rated power specification

2. Correct any oil, fuel, or induction leaks

3. Check and adjust engine fuel system

4. Check and adjust engine oil pressure

After run-in, the engine is released to the installer who provides the airframe, baffling, fuel settings, and all aircraft interface considerations. Break-in is not complete until the engine oil consumption has stabilized and many hours of operation have elapsed."​
Mahlon (Russell) has published engine Run-In and Break-In instructions in various places on the 'net, including VAF. Here is one:



And Mike Busch's presentation on engine Break-In:


And article:​

 
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My engine was just IRAN'd. Aero Sport / Pro Aero said "The engine has 2 hours of test run time". I assume this 2 hours of test-run time qualifies as the "run-in" and i can proceed directly to in-flight Break-In after install and a quick ground run for leak-check?
 
My engine was just IRAN'd. Aero Sport / Pro Aero said "The engine has 2 hours of test run time". I assume this 2 hours of test-run time qualifies as the "run-in" and i can proceed directly to in-flight Break-In after install and a quick ground run for leak-check?

Yes, they did the run-in. Good to go for the break-in. Good luck with the engine!
 
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