New Engine Best Practices?

[AaronDC8402]

We're picking up 1ZX from an annual turned engine overhaul on Tuesday. We previously had the Firewall Forward HP plus STC, but opted to not use the 10:1 compression pistons in this overhaul. So, the engine is a standard IO360-A3B6D that would be in most M20J's. Triad did the engine overhaul, and AGL Aviation did the removal and reinstall. I will be asking Triad and AGL the same question, but I'm curious to hear Mooneyspace's opinions as well. 

What's the best break-in procedure and schedule for oil changes during the break-in period? Triad ran the engine for a couple hours on their stand, and AGL has ground tested the engine some. Lynn at AGL is giving us a 2 1/2 hour break in flight procedure that we will complete before our final departure home. From what little I know about new airplane engines, I know they typically use mineral oil in the first hours. For how long do you use the mineral oil? And what's the purpose of mineral oil vs regular oil? 

Any other general advice for helping get this engine last well into TBO hours?

The Firewall forward overhaul was at about 1650 hours when pulled. In it's defense (if there is one), the plane sat for about a year and a half before we bought it with only an occasional ground run.

[201er]

That's what happens when you let a lycoming sit.

Fly it down low, WOT 2700RPM LOP at or slightly below 11gph. That will run it hard while keeping the CHTs down. If I recall, I used mineral oil for the first 50 hours. It didn't fully break in till about 30-40 hours. Engine was running great no complaints prior. But the speed didn't become normal till then.

[carusoam]

Have the engine shop give you written break-instructions If you can...

The factory Reman guys probably have it on their website...

LOP is a great idea.

I followed the instructions laid out by Continental.  Which included the first few hours of how to check everything is properly installed and operating, followed by the first few flights around the pattern looking for oil leaks, then onto....  a few hours, max power, full ROP, down low, varying RPM every 15 minutes.

Varying the RPM changes the actual distance the piston travels inside the cylinder.  Thus avoiding a solid step wearing in near, but short of the extreme travel limit...

Using mineral oil is intended to be not the best lubricator...   it is a good lubricator that allows some wear to occur.

No wear = no break-in

Get ready to collect and review your engine data... The break-in procedure often shows a specific change in CHTs under identical conditions...

My engine was run at the factory. My mechanic took the flights around the pattern.

I may have taken precaution to another level.  I brought my favorite CFII along for a few hours to make sure I didn't goof something up.  I also wanted to make sure I somehow didn't mess up the warranty.

Missing some obvious engine sign could be hazardous to your welfare.

Full power flights, down low, are really enjoyable.  Not something I usually do since there are more plan Bs found at higher levels... but, in this case the cooler, denser air is used for Best cylinder cooling...

with the IO360, you probably want to consider the ignition timing you are using 25°BTDC is often preferred over 20°.  The cost, is elevated CHTs. Probably not as elevated as the 10:1 pistons though...

Did I get it...?

Best regards,

-a-

 

[Guest]

Triad should be providing break in instructions as well as first oil change intervals.  Following their instructions should satisfy their warranty requirements.  Everyone else's opinions don't count unless they are assuming the warranty.

After break in is complete oil changes 25-30 hours seem to be the norm.

Mineral "Break-in" oil has a weaker film strength than Ashlee's dispersant oil, which allows the rings to push through the oil film to make contact with the cylinder walls allowing both to break-in or seat.

Typical break-in flights are 2-3 hours long.

Clarence

[Guest paulie]

Run it hard, when rings seat you should see a marked drop in chts. Baby it and you'll glaze the cylinders.

[Tommy]

Lycoming has a break-in procedure. Follow it. It does call for 25/25 power setting at the very least. Some people are even more aggressive. I flew mine between 25/25 and 27/27 - change every 15 to 30 minutes for first 20 hours or so. Taxiing with 15" or above (and apply gentle breaks). My workshop manager said Mineral the first 50 hour. Then Aeroshell 100 for next 50. Then Aeroshell W100 only when the break in is definitely complete.

One very important thing is DO NOT COMPROMISE SAFETY ie. if you have to power down, power down. Therefore, it's best to have a very long run way to land on your first 20 hours so you only have to idle on the flare and not during the approach but you will be crossing the fence at 80 kt or above. Try to do it when it's cold outside to keep the temperature down. And don't forget your fuel burn will be a lot more!

Watch your engine monitor like a hawk and fly like it's going to quit any minute...

Tedious but it's well worth it when it's done right. 

Also was your engine affected by the latest SB? 

[AaronDC8402]

Our engine was not affected by the latest SB.

Sounds like descents are going to be interesting. Keeping the power in and descending are two things that don't go particularly well together in a Mooney. I guess the good news is that we'll already be down lower than I typically fly. 

[Tommy]

16 hours ago, AaronDC8402 said:

Our engine was not affected by the latest SB.

Sounds like descents are going to be interesting. Keeping the power in and descending are two things that don't go particularly well together in a Mooney. I guess the good news is that we'll already be down lower than I typically fly. 

Descent is the most interesting part. You don't want to be power down for too long but at the same time you don't want to fly in the yellow / red arc! 

So start your descent from the long way away and pick a nice day for flying.

But like Clarence @M20Doc was saying, most if not all the break in were done the first couple of hours anyway...

[ArtVandelay]

Why is the car engines different? Engine builders seem to break-in oils with antiscuf (ZDDP) and run it on a test stand? If buy a new plane do I have to do this? Seems like OWT ?

[Danb]

Yep, I bought two new planes, my second 201 in 1988, the factory rep flew it from Kerrville to Wilm De for me to see, then back. They flew it full bore for 20 more hours, I flew it home from Kerrville flat out, by the time it first got to my hanger it was broke in with about 50 hours on it. The guy that bought it from me in 2006 meaning the plane is  now 30 yrs old I believe it's still going strong on the first engine. At least 5 yrs ago with over 2000 hours, the break in period is essential. 

[Guest paulie]

My brand new factory continental came with test run data sheet. Unrelated, I've been told BMW motorcycles run new engines at full bore, if it doesn't blow up, good to go, no break in suggested by factory

[carusoam]

The automotive world builds to exacting standards... highly automated.  The engines are water cooled and temps are much better controlled.

They will still give instructions on what to avoid in the first few miles or when that first oil change should occur...

I think they have left out the words break in since the new millenium arrived...

The engine computer might have controls placed on it regarding WOT during its first few miles....

just speculating...

Best regards,

-a-

[jetdriven]

On 8/1/2017 at 10:18 AM, paulie said:

My brand new factory continental came with test run data sheet. Unrelated, I've been told BMW motorcycles run new engines at full bore, if it doesn't blow up, good to go, no break in suggested by factory

 My lycoming factory engine  had a test sheet as well.  At the BMW 3-Series factory in Munich, they test drive the cars on a rollers in a very strenuous program.  up to 140 MPH and full power for quite a few minutes. I asked how many engines blow up or start knocking and he said "never". 

[AaronDC8402]

We have completed the initial Lycoming test flight procedure. No anomalies. The engine runs incredibly smooth. The biggest issue at this point has been keeping temps down. The rubber flap on the top of the engine baffle keeps flipping backwards in flight. Temps are staying about 360-370 in cruise when the flap is in the correct orientation, but jumping to 400 when it inverts. The engine seems to sit about 1/2" lower now than before overhaul, and I think that is accounting for the extra space allowing the flap to flip over. I haven't test flown it yet, but I think I've resolved that issue this morning. I should get to fly this afternoon or tomorrow to confirm.

The power isn't impressing me yet, but it sounds like that's expected to increase slightly as everything wears in. We also had the HP+ STC previously, but went back to the non-HP+ on this overhaul. 

 

As for automotive engines, I know from my work experience that Mercedes test runs every engine on a test stand fully instrumented. The cars are also test run after final assembly of the vehicle. At that point, there's not much to break in.

[Guest]

8 hours ago, AaronDC8402 said:

We have completed the initial Lycoming test flight procedure. No anomalies. The engine runs incredibly smooth. The biggest issue at this point has been keeping temps down. The rubber flap on the top of the engine baffle keeps flipping backwards in flight. Temps are staying about 360-370 in cruise when the flap is in the correct orientation, but jumping to 400 when it inverts. The engine seems to sit about 1/2" lower now than before overhaul, and I think that is accounting for the extra space allowing the flap to flip over. I haven't test flown it yet, but I think I've resolved that issue this morning. I should get to fly this afternoon or tomorrow to confirm.

The power isn't impressing me yet, but it sounds like that's expected to increase slightly as everything wears in. We also had the HP+ STC previously, but went back to the non-HP+ on this overhaul. 

 

As for automotive engines, I know from my work experience that Mercedes test runs every engine on a test stand fully instrumented. The cars are also test run after final assembly of the vehicle. At that point, there's not much to break in.

If the spinner and cowl don't align the engine mounts or shims are installed wrong. As well as causing baffle problems other things may rub on the lower inside of the lower cowl.

Clarence

[triple8s]

Someone said if during the break in proceedure "you have to power down, power down."

I was with a fellow Mspacer and we were into the breakin proceedure on a brand new engine, about 30-40 min. when the engine started sounding different and temps after having been up and starting down had started back up again. We had been making circuits about the pattern and had just asked the tower to vector us away from the airport so we could fly off the remaining 1.5hr. Due to the change in the engine the tower was told that we wanted to make a couple more circuits during which the engine continued to change, temps were trying to climb, and it started misfiring so the breakin was interupted and my friend made a nice nearly dead stick landing. If we had not have made the additional circuits and left the airport area, we wouldve had a very different day. My point? The most dangerous time to fly an airplane is just after a mechanic has worked on it. Do NOT ever think you cant land when needed or declare an emergency. If you think something isnt right, dont take the chance. When we got on the ground, the main fuel line was so loose i could tighten it 3 full turns with my fingers. The blue fuel stains everywhere. I have to wonder how close we had come to being a statistic. My buddy, fellow MSpacer did a GREAT job in the left seat that day. You know who you are.

[jetdriven]

Great decision making right there. 

[carusoam]

Thanks for sharing the details, Eights!

Best regards,

-a-