New IO-360 Break In

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JC150

Pre-takeoff checklist
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JC150
Just had a new IO-360 installed in my Cherokee Arrow. Can anyone please tell me how to break the engine in? The only thing the mechanic said was “run in hard for 10 hours, change the oil, run it hard for 25 hours, change the oil, and you’re done”

But I feel like there should be more specifics. Do I run full rich for 35 hours? Do I run full MP and full RPM for 35 hours?

Appreciate any help
 
It needs to be done properly to ensure the longevity of the engine.

Your ultimate goal is to ensure that the rings fully seat themselves to the cylinders. If you don’t follow the break-in procedure according to the engine builders specifications, than you run the risk of scoring the cylinders and ultimately voiding the warranty. Scored cylinders produce a high oil consumption, low compression and generally prevent the engine from making it to TBO.

It’s also to be noted that the engine needs to be cool to the touch before flying it again after you finish with a flight. Also, during the break-in period do not do any slow flight, touch and goes, or pattern work. Use this time to get some cross-country hours.

You need to comply with the procedures given for your specific engine, which the builder and manufacturer should supply to you.
 
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I think the first question that needs to get answered is what kind of engine overhaul did you get? Was the engine run in on a test stand of some sort? Break in instructions will differ if it was or was not.
 
Ryanb said:
It needs to be done properly to ensure the longevity of the engine.

Your ultimate goal is to ensure that the rings fully seat themselves to the cylinders. If you don’t follow the break-in procedure according to the engine builders specifications, than you run the risk of scoring the cylinders and ultimately voiding the warranty. Scored cylinders produce a high oil consumption, low compression and generally prevent the engine from making it to TBO.

It’s also to be noted that the engine needs to be cool to the touch before flying it again after you finish with a flight. Also, during the break-in period do not do any slow flight, touch and goes, or pattern work. Use this time to get some cross-country hours.

You need to comply with the procedures given for your specific engine, which the builder and manufacturer should supply to you.
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I think you mean glazed, not scored?

High MP settings for high cylinder pressures to seat rings. Run it hard but keep it as cool, so shallow climbs. No oil additives. Minimize low power ops. Gentle power changes.
 
So the document says to reduce to climb power after takeoff, my POH for my arrow does not have a climb power setting...

Additionally it says to reduce to 75% power for the first hour, 65% power for the second hour.

My mechanic is saying to run it full power/full rpm/full mixture for the first 15-30 minutes, then leave wide-open-throttle and reduce to 2500 rpm for the next 1.5 hours.

He says dont exceed 3,000 feet and run it at full mixture the entire flight including taxi.

I dont see anything about that in the document. Can anyone here give me some guidance?
 
Was your engine run-in at the factory and have a factory warranty? If so, do what the factory says for obvious reasons. I don't disagree with your mechanic. Maintaining high cylinder pressures seats rings, but if you have a factory engine that was run on their test stand most if not all the high cylinder pressure ring seating is already done.
 
They put it on a test stand but my mechanic says the ring seating has not been done. He also says don't lean at all. But another thing i'm reading online says to set up 75% power and lean to 100 deg ROP. Which should I do? The manual doesn't say
 
You should have gotten written instructions on this with the new engine. Your mech probably has them, ask to see it.
 
I got the paperwork which is identical to the link at the top of this page. It doesn't say anything about leaning in flight. Should I just leave it full rich?
 
The paperwork says 75% power. Do I do that with WOT and use RPM to achieve 75%? Or do I pull MP and leave it at 2700RPM? Or both? There's no guidance in this paperwork
 
JC150 said:
I got the paperwork which is identical to the link at the top of this page. It doesn't say anything about leaning in flight. Should I just leave it full rich?
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JC150 said:
The paperwork says 75% power. Do I do that with WOT and use RPM to achieve 75%? Or do I pull MP and leave it at 2700RPM? Or both? There's no guidance in this paperwork
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Are these not questions that your mechanic can answer???
 
JC150 said:
I got the paperwork which is identical to the link at the top of this page. It doesn't say anything about leaning in flight. Should I just leave it full rich?
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My POH (IO-360) says to lean for smooth operation. Of course it was written back in 1978 before engine monitors. I’ve been told running rich will wash the oil off the cylinder walls resulting in shorter lifespan. Of course if you are trying to break in the cylinders you need a little wear.
Do you have a power table?
Mine says at 4000’, 2600rpm, 12.3 gph is 75% power. When time comes I will run it there following Lycoming SB link above.
Edit: there is an IO-360 app, you enter temp, altitude and get power settings.
 
Ryanb said:
Are these not questions that your mechanic can answer???
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He said “use 75% power, run it hard”

My plan is to stay at 2,000 feet. I would have to reduce power to achieve 75%. But do I reduce with MP or RPM?
 
teejayevans said:
My POH (IO-360) says to lean for smooth operation. Of course it was written back in 1978 before engine monitors. I’ve been told running rich will wash the oil off the cylinder walls resulting in shorter lifespan. Of course if you are trying to break in the cylinders you need a little wear.
Do you have a power table?
Mine says at 4000’, 2600rpm, 12.3 gph is 75% power. When time comes I will run it there following Lycoming SB link above.
Edit: there is an IO-360 app, you enter temp, altitude and get power settings.
Click to expand...


I looked in the App Store but can’t find it. Can you tell me the name of the app?
 
JC150 said:
He said “use 75% power, run it hard”

My plan is to stay at 2,000 feet. I would have to reduce power to achieve 75%. But do I reduce with MP or RPM?
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Reduce power by reducing RPMs. You need high MP to set the rings. -Skip
 
JC150 said:
I looked in the App Store but can’t find it. Can you tell me the name of the app?
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You’re right, I can’t find it either,I guess it was removed.

287d64da172629d1a26f22fee9d393e3.jpg
 
In this case rich is about keeping it cool. I ran mine greater than 75% for a several hours. I don't think full throttle is necessary but it won't hurt. I adjust the rpm every few minutes to mix it up a little.
 
Ok, so my made a guide for the break in. Can someone please offer some critique?

1) Normal run-up but don’t cycle prop


2) Normal Takeoff

Monitor fuel pressure and fuel flow
If too high, reduce with mixture
If too low, abort the takeoff

If you don’t get within 100rpm of 2700, abort the takeoff

Abort takeoff if EGT exceeds 1500


3) Full Power Shallow Climb, 200-300fpm


4) Circle over the airport for 2 hours

- cruise altitude (2,000-3,000ft)

- Wide Open Throttle, Full Mixture for 2 hours

- Reduce RPM to 75-80% power for the first 60 minutes

- For the next 60 minutes run between 65-75% power. Every 15 minutes change RPM’s by a few 100 rpm then 75% again.


5) Descents maintain 2700rpm and just use throttle


CHTs must stay below 400

Oil Temp must stay below 200

How does this look?
 
teejayevans said:
Why not cycle the prop?
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Because you're taking oil away from the rest of the engine to feed the prop in a typical SE install?

That's aside from the fact that the OEMs have service bulletins recommending against lots of prop cycling on a new engine. I'd do it once to make sure the prop is controllable and leave it at that. In fact, that's what I do regardless of how new or old the engine is, for this reason.
 
JC150 said:
Ok, so my made a guide for the break in. Can someone please offer some critique?

1) Normal run-up but don’t cycle prop


2) Normal Takeoff

Monitor fuel pressure and fuel flow
If too high, reduce with mixture
If too low, abort the takeoff

If you don’t get within 100rpm of 2700, abort the takeoff

Abort takeoff if EGT exceeds 1500


3) Full Power Shallow Climb, 200-300fpm


4) Circle over the airport for 2 hours

- cruise altitude (2,000-3,000ft)

- Wide Open Throttle, Full Mixture for 2 hours

- Reduce RPM to 75-80% power for the first 60 minutes

- For the next 60 minutes run between 65-75% power. Every 15 minutes change RPM’s by a few 100 rpm then 75% again.


5) Descents maintain 2700rpm and just use throttle


CHTs must stay below 400

Oil Temp must stay below 200

How does this look?
Click to expand...

Why the paranoia and circling over the airport for a full two hours if the engine has already been run in on a run stand? Have you already flown the airplane now that the engine is installed or is this your suggested procedure for the first flight?

Personally, I think you're making this engine break in a bigger deal than it needs to be. I've never had trouble getting a Lycoming with a constant speed prop broke in, it will likely be done in a relatively short period of time. The airplanes with fixed pitch props seem to take longer because you can't control firing pressure as easily as you can with the CS prop.
 
mondtster said:
Why the paranoia and circling over the airport for a full two hours if the engine has already been run in on a run stand? Have you already flown the airplane now that the engine is installed or is this your suggested procedure for the first flight?
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From what I've seen, engine failure is much more common on new engines. Something doesn't get sealed right, seated right, assembled right, and doesn't stay together. Better to be in a high key position over the airport in case something happens. Even if not a catastrophic failure, if you see dropping oil pressures, high temps, or any other indicators you have a quick and easy descent to the airport.
 
midwestpa24 said:
From what I've seen, engine failure is much more common on new engines. Something doesn't get sealed right, seated right, assembled right, and doesn't stay together. Better to be in a high key position over the airport in case something happens. Even if not a catastrophic failure, if you see dropping oil pressures, high temps, or any other indicators you have a quick and easy descent to the airport.
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No argument there, my thought was that if this was run in on the stand the major problems and oil leaks should have been addressed. Then once it is installed on the airframe it should have been run again to confirm the proper installation. After that I wouldn't stray real far from the airport but I don't feel it is absolutely necessary to be right over the airport.

Admittedly, I may be a bit callous to this having been around a lot of engine break ins and seeing very few problems.
 
mondtster said:
No argument there, my thought was that if this was run in on the stand the major problems and oil leaks should have been addressed. Then once it is installed on the airframe it should have been run again to confirm the proper installation. After that I wouldn't stray real far from the airport but I don't feel it is absolutely necessary to be right over the airport.
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I have heard of failures that took a little time to appear, such as an oil passage that was blocked, or some random bolt that didn't get torqued. Granted, those may not even show themselves in the first two hours of operation, but we must leave the pattern at some point. I still prefer though to remain near the airport at least for that amount of time.

Even after any type of extensive inspection or annual, I have been known to keep it near the airport for the first 15-30 minutes just making sure everything is good to go. After my last annual, I discovered a rubbing noise during the control check before getting in the airplane which we traced to an electrical wire than was rubbing a control cable. Minor issue for sure, but you never know.

Maybe I'm paranoid, but its served me well so far.
 
My cylinder break-in instructions (well, totally diff engine but I think the basics apply) included cycling only to a 100rpm drop. You need to know if the darn thing works before you go.
 
mondtster said:
Why the paranoia and circling over the airport for a full two hours if the engine has already been run in on a run stand? Have you already flown the airplane now that the engine is installed or is this your suggested procedure for the first flight?

Personally, I think you're making this engine break in a bigger deal than it needs to be. I've never had trouble getting a Lycoming with a constant speed prop broke in, it will likely be done in a relatively short period of time. The airplanes with fixed pitch props seem to take longer because you can't control firing pressure as easily as you can with the CS prop.
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I haven't flown it. Yes it was put on a stand but it wasn't broken in. Thats what the flight is for.

I'm concerned with not breaking it in correctly. I want to avoid glazing, but i also dont want to run it too soft. I was hoping someone would look at my script and critique if i should do something differently?
 
So you ask for advice, guys reply, and you tell them they’re wrong? Sounds like you have it all figured out. Go fly it.
 
JC150 said:
I was hoping someone would look at my script and critique if i should do something differently?
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#5 my instructions include avoid descents at high rpm. I think that causes the prop to drive the engine which possibly contributes to ring flutter.
 
JC150 said:
1) Normal run-up but don’t cycle prop
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In my banner flying days, just about every engine in our fleet would need at least one cylinder every season. Flying for hours on end at high power and low airspeed will do that to you. Since we usually needed the airplane back online asap, I flew a lot of late day/early morning break in flights in my time there. I'd usually pick it up late afternoon after the towing was done and fly it 5-6 hours or until sunset. Then I'd get back in it 5am the next morning and fly it until about 10 then we'd start pulling rags with it. Every time the mechanics would tell me the same thing. 'Get it in the air right away. Don't idle it on the ground and I wouldn't do a runup at all but if you need to do one, make it quick'.
 
Stewartb said:
So you ask for advice, guys reply, and you tell them they’re wrong? Sounds like you have it all figured out. Go fly it.
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Never told anyone they are wrong. Except you, you’re wrong in assuming I have it all figured out. That’s why I’m here looking for constructive criticism on the script I made
 
Personally I think you are over thinking it. All that matters is you take off with little delay, run at no less than 75% power until the temps stabilize.
 
Grum.Man said:
Personally I think you are over thinking it. All that matters is you take off with little delay, run at no less than 75% power until the temps stabilize.
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That’s my feeling too. Only thing I’d add is that I’d favor power reduction via rpm reduction over manifold pressure reduction. At least to a point.
 
JC150 said:
Never told anyone they are wrong. Except you, you’re wrong in assuming I have it all figured out. That’s why I’m here looking for constructive criticism on the script I made
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I just broke a new motor in. It was run for an hour at the factory. I have the dyno log. I followed the factory instructions after that. Logged it as such. Works great. Warranty is valid. Not a big deal.
 
Grum.Man said:
Personally I think you are over thinking it. All that matters is you take off with little delay, run at no less than 75% power until the temps stabilize.
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Thank you! should I alternate power settings above 75% as well or just run it at say 80% for 2 hours?
 
UPDATE:

I put the first 6 hours on the engine. I leveled off at 3,000' and flew WOT and used RPM to change % of power. Full Rich Mixture.

My question is my CHTs are not dropping. I was told the rings are seated when I noticed a drop in CHT temps. After 6 hours there's still no change..

79%pwr (27"/2400rpm) 321/314/316/308
83%pwr (27"/2500rpm) 324/316/318/312
86%pwr (27"/2600rpm) 327/321/324/317

What else do I need to do to get these rings seated? I feel like 6 hours should have been enough... thanks!
 
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