Cylinder Break-in & flight delivery

mandm

mandm

En-Route
PoA Supporter
Joined
Feb 7, 2020
Messages
2,836
Location
Chicago
Display Name
Display name:
Michael
Picking up a plane with 2 new cylinders, asked the mechanic about break-in and he mentioned it has mineral oil but didn’t say much about how to run it. Any thoughts on how to run the engine on the journey back and for how many hours this process would take to ensure the new cylinders are good to go. Have read a couple articles online that say to shorten the taxi and run-up (only cycle prop once), kind of feeling a bit weirded out skipping steps with a plane new to me.
 
Last edited:
Don't fly to high. Make sure you can get 75%. Wide open throttle at high altitude ain't gonna do it. Knew a guy who got a new engine. Spent to much time at high altitudes and rings never seated properly. Air to thin to put enough pressure in the cylinders. It was a Lycoming O-360. May or may not be a thing with other engines. I dunno.
 
mandm said:
Picking up a plane with 2 new cylinders, asked the mechanic about break-in and he mentioned it has mineral oil but didn’t say much about how to run it. Any thoughts on how to run the engine on the journey back and for how many hours this process would take to ensure the new cylinders are good to go. Have read a couple articles online that say to shorten the taxi and run-up (only cycle prop once), kind of feeling a bit weirded out skipping steps with a plane new to me.
Click to expand...

Lycoming suggests 75% power for 2 hours and 3000' and then wide open throttle for another 30 minutes. Land and add oil. Then the second flight for 2 hours at 65-75% power and then wide open for another 30 minutes. After those 2 flights my new motor stopped using oil and was broke in at 5 hours run time. I now have 330 hrs on it and it has been perfect.
Here's my last oil analysis.
IMG_1211.JPG
 
Stewartb said:
Run it at 75% power or more for the first few hours until oil use stabilizes, then 65% plus for a few hours. Once rings are seated you’re golden.

Minimize taxi and prop cycling for initial flight. Stay local until you’re happy it’ll keep running. Expect the new cylinders to run a bit hot for the first half hour or so.

http://www.continental.aero/xPublications/xService Bulletins/Experimental PMA/SIL012/
Click to expand...


Would you say 20 minutes out, 20 minutes in and then land? Turn off and start again or?
 
luvflyin said:
Don't fly to high. Make sure you can get 75%. Wide open throttle at high altitude ain't gonna do it. Knew a guy who got a new engine. Spent to much time at high altitudes and rings never seated properly. Air to thin to put enough pressure in the cylinders. It was a Lycoming O-360. May or may not be a thing with other engines. I dunno.
Click to expand...

What altitude is high? How do people put west deal with the break-in’s?
 
Gary Ward said:
Lycoming suggests 75% power for 2 hours and 3000' and then wide open throttle for another 30 minutes. Land and add oil. Then the second flight for 2 hours at 65-75% power and then wide open for another 30 minutes. After those 2 flights my new motor stopped using oil and was broke in at 5 hours run time. I now have 330 hrs on it and it has been perfect.
Here's my last oil analysis.
IMG_1211.JPG
Click to expand...
How do you know the break-in is complete? Sorry complete newbie here.
 
mandm said:
Any thoughts on how to run the engine on the journey back and for how many hours this process would take to ensure the new cylinders are good to go.
Click to expand...
Find out the brand of new cylinder installed and follow those OEM instructions to the letter. Not all cylinders are created equal.
mandm said:
How do you know the break-in is complete?
Click to expand...
Usually when your oil consumption stabilizes.
 
Rather than trusting a bunch of random commenters on the internet who may or may not know anything about engines, I'd suggest finding out what the OEM recommends for a break in procedure. I'd also confer with the shop that performed the work and follow their suggestions. I would not want to be in a debate over whether the break in was performed properly or not, if a problem should arise.
 
mandm said:
How do you know the break-in is complete? Sorry complete newbie here.
Click to expand...
I have noticed that there was a noticeable drop in CHT on new cylindres indicating seating, usually in under an hour. Actually full breaking in may take quite a few hours indicated by a stabilization of oil consumption. Also it's better to run at full power than lower than 75% to break in. In fact as long as CHTs are under red line I would not worry about full power until ring seating. You might get better seating. Engines are certified to far higher standards. I once read to 350 hours at full power.
 
mondtster said:
Rather than trusting a bunch of random commenters on the internet who may or may not know anything about engines, I'd suggest finding out what the OEM recommends for a break in procedure. I'd also confer with the shop that performed the work and follow their suggestions. I would not want to be in a debate over whether the break in was performed properly or not, if a problem should arise.
Click to expand...
:yeahthat:
 
mandm said:
What altitude is high? How do people put west deal with the break-in’s?
Click to expand...
High is where the air is to thin to give you enough manifold pressure to make 75% power. Or whatever power you should have to do a proper break in.
 
mandm said:
What altitude is high? How do people put west deal with the break-in’s?
Click to expand...
luvflyin said:
High is where the air is to thin to give you enough manifold pressure to make 75% power. Or whatever power you should have to do a proper break in.
Click to expand...
Generally considered to be anything above about 7,000 msl.

https://www.pilotsofamerica.com/community/threads/teach-me-about-engine-break-in.135054/

Be glad it's Chicago in the winter. That will help to keep CHT's and oil temp in the acceptable range to reduce the chance of glazing the cylinders.
 
mandm said:
Would you say 20 minutes out, 20 minutes in and then land? Turn off and start again or?
Click to expand...
No. First flight should be longer rather than shorter. When I broke-in my new engine, my first flight was 2 hours at 80% power at 3000 MSL circling my home drome (elev 23) a few miles out.

I followed my engine builder's instructions for break-in to the letter.
 
mandm said:
Picking up a plane with 2 new cylinders, asked the mechanic about break-in and he mentioned it has mineral oil but didn’t say much about how to run it. Any thoughts on how to run the engine on the journey back and for how many hours this process would take to ensure the new cylinders are good to go. Have read a couple articles online that say to shorten the taxi and run-up (only cycle prop once), kind of feeling a bit weirded out skipping steps with a plane new
mondtster said:
Rather than trusting a bunch of random commenters on the internet who may or may not know anything about engines, I'd suggest finding out what the OEM recommends for a break in procedure. I'd also confer with the shop that performed the work and follow their suggestions. I would not want to be in a debate over whether the break in was performed properly or not, if a problem should arise.
Click to expand...



I agree with this^^^^^
I didn't ask on the internet when it came time to start my new engine. I followed lycomings instructions exactly. I will post them next time I get into my logs.

I realize the OP only had a couple cyls replaced, so I would follow the instructions his mechanic suggests.

The longer lycoming version was, 5-10 minutes with the cowl off to check for leaks and to warm up the engine.
Then put the cowl on, face the plane into the wind and run it at 1500 rpms for 20 minutes.
Then let it cool.
Then without delay go fly the 2-2.5 hour flights. Once the oil consumption stabilizes they consider it "broke in"
Like said after the second flight my motor pretty much stopped using oil. It uses a qt every 12 hours now.

I have a interesting story about ring spacing and oil consumption, but I will save that for another day.
Click to expand...
 
Last edited:
You must log in or register to reply here.
Back
Top