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Rebuilt engine break in question


jkarch

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1 hour ago, jkarch said:

 

Also I have an old UBG-16. Is this good enough or is there a reason to upgrade to a CGR30P?

If you have the change available... the modern engine monitors are better for a bunch of reasons...

kind of like having a new PC after 20years...

Best regards,

-a-

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5 minutes ago, carusoam said:

If you have the change available... the modern engine monitors are better for a bunch of reasons...

kind of like having a new PC after 20years...

Best regards,

-a-

I wonder if it would help tell me when the engine is broken in, saving me some $ in 100LL. By going through data logging it could help

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14 hours ago, jkarch said:

100 hours before flying over mountains? Seems like a lot! How does it work with the bathtub curve? 30 - 40 plus oil analysis perhaps, but my last three samples showed a happy engine, and the cam was shot!

 

That's what I read - can't find the reference now. The bathtub chart shows first 100 hours or so. 
Yes many people see oil analysis as a low sensitivity and low specificity test but I wonder if a new engine and an old engine's failure modes (out of tolerance vs wear and tear) are sufficiently different that oil analysis has different sensitivity and specificity when it comes to new engines. But we don't really have another test to compare to (certainly not one that's as cheap and accessible as the oil analysis). 

Edited by Tommy
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11 hours ago, M20Doc said:

Some days I love Apple products, others not so much.

Clarence

The old Apple campus was located at 1 Infinite Loop, Cupertino, CA USA. An "infinite loop" is generally considered to be a programming error. Just sayin'. ;)

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New mechanical systems have terrible records of working perfectly in the first hundred or so hours...

If something is wrong... the first 20 hours is when those things show up...

Break-in is one of those things you can’t let-up on... a failed break-in is typically glazing over the cylinder walls... leading back to the beginning... starting over...

pulling engine data out of a monitor is perfect... you may even see the CHTs settle in flight... this requires a lot of memory for all CHTs.  What the normal temps are, and what the elevated temps are...

And comparing while flying... you need to be a multi-tasking mechanical expert...  MS has a few... and you might be one.

Much of the literature indicates that the break-in period can last 100 hours...  Expect 90% of the break-in is probably completed in the first 10 hours....

Say the CHTs come down pretty well in the first 15 hours... the engine monitor shows great temperature control of the CHTs...

Flying around extra rich for a year... sounds more expensive than a new set of cylinders...

The price of a perfect break-in, probably gets out voted by the needs of the chief financial officer...  :)

I reviewed flight after flight of my new engine’s data... the CHTs were all operating normally.  Using 27 gph will do that...

Sooner or later, you run it normally and collect more data to see how well it is operating under normal conditions...

I brought Byron along for one of my post break-in flights... or extended break-in flights... he was in NJ, and was going to attend a NJMP fly-in...

Its always good to bring somebody along... :) we captured really interesting VSI numbers... along with some pretty nice ASI numbers...

One of these days, I’ll be getting a new engine monitor... color, collecting all the data...

PP thoughts,

-a-

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  • 1 year later...

I'm joining this thread now because I have 10 hours on my overhauled A3B6. The engine was run in a test cell at Western Skyways. I have the data. What surprised me was how short the runs were. With all the information out there about running hard for over an hour during break in, these short runs are counter intuitive.

I also found, like others, that there are many variations on how to do this break. Much of it vague. Considering the consequences of screwing it up, I would think, by now there could be a set of hard fast rules to follow for the poor soul who has limited mechanical knowledge.  The second part is the length of time involved for the break. For someone who doesn't fly a great deal, the break in process could take a year or more at altitudes that allow 75% power. That is problematic. I fly from an airport that starts at 3,500 ft. In summer the DA is often up to 5,000. To leave the area I need to go to 9,000 to comfortably clear terrain on my way to almost anywhere. If I need to go IFR I need 10,000 or more.

I also wonder what do flight schools do when one of their airplanes gets a fresh engine. Certainly they don't take it out of service for pattern work for 50 hrs. Or maybe they don't care if they end up with high oil consumption. It probably comes down to a financial trade off. They can buy a lot of oil for 50 hrs of revenue flights.

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Here's a copy of the test cell report from Lycoming for my rebuilt A3B6. I'd be interested to see the report from Western Skyways to compare.

I've been associated with several flight schools over the years and typically they just put a restriction to use mineral oil, cruise at >65% power and no touch and goes for 50 hours or so. Most flight schools get TBO or greater on the engines since they are used a lot. At the two part 135 operations I've been involved with we just used mineral oil and flew the normal routes.

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Test Report.pdf

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2 hours ago, rotorman said:

I'm joining this thread now because I have 10 hours on my overhauled A3B6. The engine was run in a test cell at Western Skyways. I have the data. What surprised me was how short the runs were. With all the information out there about running hard for over an hour during break in, these short runs are counter intuitive.

I also found, like others, that there are many variations on how to do this break. Much of it vague. Considering the consequences of screwing it up, I would think, by now there could be a set of hard fast rules to follow for the poor soul who has limited mechanical knowledge.  The second part is the length of time involved for the break. For someone who doesn't fly a great deal, the break in process could take a year or more at altitudes that allow 75% power. That is problematic. I fly from an airport that starts at 3,500 ft. In summer the DA is often up to 5,000. To leave the area I need to go to 9,000 to comfortably clear terrain on my way to almost anywhere. If I need to go IFR I need 10,000 or more.

I also wonder what do flight schools do when one of their airplanes gets a fresh engine. Certainly they don't take it out of service for pattern work for 50 hrs. Or maybe they don't care if they end up with high oil consumption. It probably comes down to a financial trade off. They can buy a lot of oil for 50 hrs of revenue flights.

I think there's a difference between "breaking in" new cylinders and "running in" a rebuilt or overhauled motor.  Someone correct me if I'm wrong, but I believe the latter is just to demonstrate the engine as a unit performs up to some specifications.

I think breaking in cylinders is a different topic and that's where people talk about running hard for the first couple hours, and the recommendation is to run at high cruise power until CHT's drop a little.  It seems like it should be doable (and should be done) on the first flight.  IIRC, the first 50 hour thing is when you run it on straight mineral oil.  Mike Busch from Savvy Aviation does a webinar series on EAA (most of them archived on YouTube), and I'm sure someone can find the one he did on breaking in new cylinders last year

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Break in procedures are very specific...

Each step has a reason for being...

By the time the engine is mounted in the plane... the steps are different, for various reasons...

Oddly, they all get called break-in runs...  why not...?

 

Read the procedures very closely....  just to understand them...

Sure, the break-in may take 100hrs to complete...   what does that mean..?

 

No... nobody is going to specifically keep running full power, full Rich, at low altitudes to continuously break in an engine...

What they are saying... while you fly your plane for the next 100 hours.... if you watch your engine monitor.... or review it’s data...  You will see the affects of the break-in continue to occur for some hours.... until they finally tail off.

 

The flight school I used... was specific about what type of flight was allowed for a recently OH’d engine... they preferred long X-countries, over pattern work...

 

Engine break in is really easy... Read the instructions... or discuss them with your mechanic... or hire a Mooney specific CFII to go along on a few hours of flight...

You won’t need to be a mechanic, an engineer, or CFII yourself... but it could be helpful if they are on your team... :)

When everything goes as planned... you might think that was overkill...

If there is any fan hitting feces involved... it would be good to have an SIC.... in the moment...

Years ago... Expecting to witness the affects of Break-in on my new factory reman’d IO550... I scoured hours of data. Nothing obvious showed...

So... following the procedure worked really well...

PP thoughts only, not a mechanic or a CFII...

Best regards,

-a-

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  • 1 year later...
On 6/19/2019 at 8:15 PM, carusoam said:

+1 for following the manufacturer guidelines...

The misery/mystery of engine break-in have all been broken...

Break-in of an NA engine typically includes

a set of flights... the first ones orbit the airfield looking for leaks and other tests...

The Long XCs typically include... the Jersey Shore runs...1k’ AGL

  • High power
  • Cold running, cold air, maximum cooling
  • Full mixture
  • alternating rpms every 15 minutes
  • Keep an eye on CHTs, you might see the break-in actually occur...

If the engine was run on a test stand, most of the Break-in may have occurred already...

PP thoughts only, not a mechanic...

Best regards,

-a-

How did you orbit the field at 75% power and still managed not to run into a C152? 

I'm facing the prospect of a run-in/break-in at a field surrounded by busy routes and a training area. Is it advisable to climb to 6000 feet to stay away from traffic?

Also, this article below recommends 2700 RPM and 23 MP for the return to the airport which I don't think is doable in an Ovation. I think even if you had a long runway, you'd be at idle power for a prolonged time while you float. Is it really harmful to stick to usual power settings when in the pattern? 

www.aviationconsumer.com/uncategorized/engine-break-in-flights-know-the-power-settings

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If it is a factory rebuilt, it has been run in at the factory in a test cell. Also true if it was overhauled at one of the larger overhaulers. In that case, just fly it reasonably at 65% or greater and don't stress about it.

If it is a field overhaul and hasn't been run in a test cell, then the first few hours are more critical.

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Edited by PT20J
Changed don't "stress it" to don't "stress about it" to clarify.
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On 6/20/2019 at 12:15 AM, jkarch said:

So it sounds like with a pre tested engine for 30 hours total don’t go above 5k ft altitude ( 1k-2500 preferred ) or 75 percent power unless cycling between 65 and 75 even if temperatures and oil consumption stabilize? Also sounds like cowl flaps should be open the whole time, full rich operation, and keep 75 percent power on descent. Occasionally run at full power? Oil change at 10 then another 20-30?

what about traffic pattern? Cowl flaps open or closed? What power settings?

When can I finally climb above 5k?

-J

8. If the  engine  and  aircraft are  operating  to correct specifications per  the Lycoming  Operator’s Manual, increase  engine  power to  the  maximum airframe  recommendations and  hold  for 30  minutes.

This seems to be after the first 2 hours of flying.  First hour at 75%, second hour varying between 75% and 65%

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My class D ceiling is 2500’, so I just notified the tower I was going to climb above their ceiling and do a hold…after 2 hours I landed, check for leaks. After that I flew as normal staying low enough so I could continue to run at 65%.
I changed the oil after about 10 hours, it was clean and oil level were steady so break in was complete.

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Just like Tom did, talk to your tower and orbit a ~1000’ above their Delta. i’ll do 2 hrs as well if all is looking fine. 75% power or higher first hour then alternating 65-75% second hour. As an example this is very doable below the Bravo in my SOCAL airspace. See the manufacturers service bulletin on break in procedures and don’t baby the engine as well as avoid ground running it if it’s it’s first run.


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1 hour ago, kortopates said:

Just like Tom did, talk to your tower and orbit a ~1000’ above their Delta. i’ll do 2 hrs as well if all is looking fine. 75% power or higher first hour then alternating 65-75% second hour. As an example this is very doable below the Bravo in my SOCAL airspace. See the manufacturers service bulletin on break in procedures and don’t baby the engine as well as avoid ground running it if it’s it’s first run.


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That's the part that really creeps me out, if I just had new cylinders put in, every bone in me would want to quadruple-check EVERYTHING during the runup :unsure:

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That's the part that really creeps me out, if I just had new cylinders put in, every bone in me would want to quadruple-check EVERYTHING during the runup :unsure:

Of course, the manufacturer bulletin details multiple startups to quickly verify everything; especially leak checks and mags. But you want to minimize your ground running as much as possible before taking off.


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My question is minimum ground run but you need to warm up the engine before takeoff so what is the quickest you would takeoff from startup? When oil temp bumps off the dot or touches the green? Or is there a min CHT to reach before applying full throttle on a new engine? 

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54 minutes ago, Will.iam said:

My question is minimum ground run but you need to warm up the engine before takeoff so what is the quickest you would takeoff from startup? When oil temp bumps off the dot or touches the green? Or is there a min CHT to reach before applying full throttle on a new engine? 

The radials pretty much had a standard requirement of 100 C CHT and 40 C oil temp before applying takeoff power.

Lycoming guidance is generally to avoid excessive ground operation because cooling is not optimal on the ground. Generally the taxi to the runway is sufficient to warm the engine for takeoff. The engine is considered warm enough if it can take full power with smooth operation. 

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7 hours ago, Will.iam said:

My question is minimum ground run but you need to warm up the engine before takeoff so what is the quickest you would takeoff from startup? When oil temp bumps off the dot or touches the green? Or is there a min CHT to reach before applying full throttle on a new engine? 

Warm, but not overheated on the ground.  If you’re worried about either plug in your engine heater to warm the engine first.

 

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18 hours ago, Will.iam said:

My question is minimum ground run but you need to warm up the engine before takeoff so what is the quickest you would takeoff from startup? When oil temp bumps off the dot or touches the green? Or is there a min CHT to reach before applying full throttle on a new engine? 

Just min oil temps are specified for the K's with 75F for runup and 90F for full power/takeoff. Bigger 550's do specify a min CHT but not the TCM TSIO-360's.

But otherwise excessive ground running is more along the lines of worrying too much about getting max FF, max boost and max RPM perfect by running it at high power on the ground to get these set; or even high speed taxi runs to build confidence. Getting them into the ball park will enable that first flight to be done safely with the option to abort once going to full power you do see anything not in the ballpark (overly lean mixture etc). But the fine tuning should be delayed till after the first flight IMO.

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