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Lycoming factory overhaul vs. rebuilt


PT20J

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I learned something in my Lycoming factory engine class today. When Lycoming gets your engine, it disassembles it, inspects the parts, discards the unusable parts, cleans and reworks salvageable parts, and puts the parts in stock for use in rebuilt and overhauled engines.

Rebuilt engines get built up using parts from this inventory plus whatever new parts are required. Since they are built under Lycoming’s production certificate, they get a new data plate with a new serial number and a new logbook.

Overhauled engines are built up the same way from the same inventory. The only part from your engine you will likely get back is the data plate. Overhauled engines are built using Lycoming’s repair station certificate so they must retain the serial number and logbooks.

So, what’s the difference except the serial number and logbook? Probably nothing. Both engines will be built to new clearances, but Lycoming’s specs allow more rework on the overhauled parts. Basically the spec requires that rebuilt engine components must be likely to undergo at least on additional overhaul. For instance, crankshaft journal dimensions can be new, -.003, -.006, -.010. A rebuilt crankshaft must be -.006 or better whereas an overhauled crankshaft might be machined down to -.010. But, I’m told that this very rarely happens because most parts retained from used engines are in pretty good shape or they get scrapped.

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Another thing I learned: If you ever order an engine from Lycoming, give them the serial number of your old engine. Manufacturers have a nasty habit of asking Lycoming to make changes to particular engines without changing the model number which would require the manufacturer to update its TCDS. So, two engines with the same model number may not be quite the same engine, and the only way Lycoming can tell for sure the parts list for a particular engine is to look up the build documentation for your serial number.

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34 minutes ago, Skyland said:

What do you know about the dual mag engines?  No more dual mags from Lycoming I would hope.  Do you know what kind of mags they supply?

I don’t think Lycoming builds new dual mag engines. You can still get a factory rebuilt or overhauled dual mag engine. You will get an overhauled dual mag though since new ones are not available.

My rebuilt IO-360-A3B6 came with Slick mags.

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 they quit shipping dual magneto engines at least before 2014, because we ordered an engine at that point and the two separate mag engine was about 4 grand more, we really thought it over and we decided to go ahead and order the -D engine. And then they said well sorry we don't build that engine anymore so here's a 2-slick mag engine for the same price. 

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8 hours ago, jetdriven said:

 they quit shipping dual magneto engines at least before 2014, because we ordered an engine at that point and the two separate mag engine was about 4 grand more, we really thought it over and we decided to go ahead and order the -D engine. And then they said well sorry we don't build that engine anymore so here's a 2-slick mag engine for the same price. 

Interesting. I talked extensively to my field rep, Brian Costello (he’d been with Lycoming forever, but has since retired) in 2018 and he assured me they would rebuild a IO-360-A3B6D then, but he talked me out of it. It turns out that there are a lot if internal parts differences between the A3B6 and the A3B6D - it’s not just the accessory case. So, the problem for Lycoming is used parts inventory because there are a lot of IO-360 variants that use more common parts and not nearly as many dual mag versions were built. I just figured that the engine was just going to become harder to maintain over time and went for the 2 Slick version.

Had to send both Slicks to Aircraft Magneto Service for IRAN at 250 hours; one for a SB on bad impulse coupling rivets, and the other because the e-gap was off and it was dropping nearly 200 rpm during the mag check.

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I just got back from a tour of the Lycoming factory. They have invested heavily to bring more work in house for better control over quality and cost. About all they don’t do now is casting and forging. The factory floor is an interesting mix of very modern highly automated machining equipment, mid-20th century machine tools, and 19th century techniques (I saw two workers mating case halves with a plastic mallet).

Lycoming is currently as much as a year behind on cylinder kits depending on the model. This is due to bringing head manufacturing in house just before Covid hit, which caused a gap in production, while simultaneously demand increased greatly beyond forecast. Apparently, a lot of folks decided to put money into airplanes during Covid — especially homebuilders. Vans went from a distant 3rd to Lycoming’s biggest customer (by “ many millions of dollars”). They are currently running 6 automated CNC lines that can machine heads from raw castings in about 45 minutes for a parallel valve head, and an hour for angled valve heads. Machines are running 24/7. 

Lycoming has about 520 employees and is shipping about 12 engines per day.

Lycoming is still shipping new dual mag engines. They get the mags from Kelly. Apparently Partenavia uses them in some model.

And, for Clarence @M20Doc, they rebuild or overhaul about two IO-720s per year.

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Interesting terminology challenge…

Gear case. vs. gear cover…. Or gear box…. :)

Sometimes we say gear case… and people think that is just the cover or casing….

In the automotive and machine world… a gear case is a whole transmission…. Box, shafts, gears….

 

On an IO360 swapping out a gear case… probably includes the cover, gears and other bits….

Oddly, the matching half of the cover… is the back end of the engine itself…

 

This can keep people from realizing how much of a gear box they have back there… :)

 

PP thoughts only, not a mechanic or English major…

Best regards,

-a-

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On 9/13/2022 at 8:51 PM, PT20J said:

I learned something in my Lycoming factory engine class today. When Lycoming gets your engine, it disassembles it, inspects the parts, discards the unusable parts, cleans and reworks salvageable parts, and puts the parts in stock for use in rebuilt and overhauled engines.

Rebuilt engines get built up using parts from this inventory plus whatever new parts are required. Since they are built under Lycoming’s production certificate, they get a new data plate with a new serial number and a new logbook.

Overhauled engines are built up the same way from the same inventory. The only part from your engine you will likely get back is the data plate. Overhauled engines are built using Lycoming’s repair station certificate so they must retain the serial number and logbooks.

So, what’s the difference except the serial number and logbook? Probably nothing. Both engines will be built to new clearances, but Lycoming’s specs allow more rework on the overhauled parts. Basically the spec requires that rebuilt engine components must be likely to undergo at least on additional overhaul. For instance, crankshaft journal dimensions can be new, -.003, -.006, -.010. A rebuilt crankshaft must be -.006 or better whereas an overhauled crankshaft might be machined down to -.010. But, I’m told that this very rarely happens because most parts retained from used engines are in pretty good shape or they get scrapped.

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Interesting that you keep the logs but none of the components contained therein. About as logical as calling an engine comprised of parts from a bin full of perfectly serviceable but used components "Zero Time". 

My admittedly limited experience with Lycoming crankshafts is that those that are removed from well cared for engines will likely still be at new specs after running to TBO or beyond.

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On 9/13/2022 at 5:51 PM, PT20J said:

I learned something in my Lycoming factory engine class today. When Lycoming gets your engine, it disassembles it, inspects the parts, discards the unusable parts, cleans and reworks salvageable parts, and puts the parts in stock for use in rebuilt and overhauled engines.

Rebuilt engines get built up using parts from this inventory plus whatever new parts are required. Since they are built under Lycoming’s production certificate, they get a new data plate with a new serial number and a new logbook.

Overhauled engines are built up the same way from the same inventory. The only part from your engine you will likely get back is the data plate. Overhauled engines are built using Lycoming’s repair station certificate so they must retain the serial number and logbooks.

So, what’s the difference except the serial number and logbook? Probably nothing. Both engines will be built to new clearances, but Lycoming’s specs allow more rework on the overhauled parts. Basically the spec requires that rebuilt engine components must be likely to undergo at least on additional overhaul. For instance, crankshaft journal dimensions can be new, -.003, -.006, -.010. A rebuilt crankshaft must be -.006 or better whereas an overhauled crankshaft might be machined down to -.010. But, I’m told that this very rarely happens because most parts retained from used engines are in pretty good shape or they get scrapped.

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Have you had the idea that they have been focusing more production on newer engines/cylinders (IO-390s) vs our older -360s?  Like maybe it’s a quicker turn time to get a rebuilt-390 than a rebuilt -360A1A?

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3 hours ago, Shadrach said:

Interesting that you keep the logs but none of the components contained therein. About as logical as calling an engine comprised of parts from a bin full of perfectly serviceable but used components "Zero Time". 

My admittedly limited experience with Lycoming crankshafts is that those that are removed from well cared for engines will likely still be at new specs after running to TBO or beyond.

It’s sort of nebulous as to what defines the engine or airplane for that matter.

Airplane is the same thing, give me a data plate and a log book and I can build you a Certified Super Cub, every single component can be replaced, but you have to have a logbook and the data plate. I guess the logbook could be reconstructed and you can get a replacement data plate from the manufacturer, so thinking about it I guess maybe all you need is a bill of sale?

I picked Super Cub because they are simple with everything available, but the value is high so people do “repair” them starting with pretty much a logbook and data plate all the time.

We have a guy who does that every year, comes down from Maine every Winter and “repairs” one every year, does beautiful work too. I believe most are sold prior to being finished.

 

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Perhaps but in GA, many people are highly concerned with hours and calendar times. "Zero time" engines have been listed as a marketing point in for sale ads for decades.  I think consumers have wised up a bit in recent years but I remember my Dad considering a factory Rebuilt “Zero Time” engine in the mid 90s.  He was not looking at it for what it was. He was looking at it like an engine that actually had zero time.  Most did not know any better then.

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16 minutes ago, Shadrach said:

Perhaps but in GA, man people are highly concerned with hours and calendar times. "Zero time" engines have been listed as a marketing point in for sale ads for decades.  I think consumers have wised up a bit in recent years but I remember my Dad considering a factory Rebuilt Zero Time engine in the mid 90s.  He was not looking at it for what it was. He was looking at it like an engine that actually had zero time.  Most did not know any better then.

Agreed, but even an Aircraft manufacturer or their designated representative can zero time an aircraft, we would I may put 50 hours on one with something Experimental on it, then place it back into conformity and sell it with zero time on it, it’s birthdate was when it was Certified not the date it first flew.

I never looked into how that was supposed to work with time limited parts, surely you can’t zero time a life limited fatigue part? I think that slipped through the cracks.

Overhaul, rebuilt, remanufactured all mean specific things. I spoke to the guy who owns Oregon Aero, he talked about the time he was visited by the FAA, they acted like they could put him in jail for what he was doing and he didn’t understand why. It boiled down that he had been advertising he would rebuild your seat, and he’s not allowed to do that, he can only repair. He said if they told him that up front it would have saved him a lot of stress. Funny guy, demonstrated his seat cushions by dropping a 3” cushion on the concrete floor, then from a standing position dropping to his knees on it. Made me cringe.

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6 hours ago, Shadrach said:

My admittedly limited experience with Lycoming crankshafts is that those that are removed from well cared for engines will likely still be at new specs after running to TBO or beyond.

Crankshafts shouldn’t wear unless metal runs through the engine, or a bearing fails, or there is oil starvation. During operation, the journals ride on an oil film and there is no metal to metal contact. During startup, the nitrite-hardened journals run on the soft bearing material with some residual oil lubrication for a few seconds until the oil pressure comes up.

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I got some clarification on Lycoming overhauled engines today. Turns out you won’t get any of your engine back including the data plate. If you order an overhaul, Lycoming will build it and ship it and you have 120 days to return your core after you receive the overhauled engine. Note that this gives Lycoming a delivery time advantage over field overhaulers since they don’t have to receive, tear down and inspect your engine. They just start putting one together from parts inventory already on hand,

The Lycoming specs for what parts can be used in an overhaul are somewhat looser than for a rebuilt, so as previously stated, some used parts that qualify for overhaul might not qualify for a rebuilt, but the differences are likely academic. New, rebuilt, and overhauled are all built on the same assembly line, by the same people, using the same processes. 

A rebuilt engine comes with a new data plate and a new logbook starting at zero time.

An overhauled engine comes with a data plate from a returned core and a new logbook with zero time since overhaul and total time carried forward from the logbooks that went with the data plate. This is why Lycoming is strict about requiring logbooks to be returned with cores - they need the total time that goes with the data plate.

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5 hours ago, Ragsf15e said:

Have you had the idea that they have been focusing more production on newer engines/cylinders (IO-390s) vs our older -360s?  Like maybe it’s a quicker turn time to get a rebuilt-390 than a rebuilt -360A1A?

They claim it’s first come, first served.

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5 hours ago, Ragsf15e said:

Have you had the idea that they have been focusing more production on newer engines/cylinders (IO-390s) vs our older -360s?  Like maybe it’s a quicker turn time to get a rebuilt-390 than a rebuilt -360A1A?

Year and half ago, when ordering rebuilt IO360 turnaround was the same for IO390. Price was higher, though and I would need a different prop that goes with STC so I quickly decided for IO360 A1A. 

 

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Some years ago you could buy an engine overhaul kit from Superior. It was a complete engine less the data plate, you assembled the engine and transferred your Lycoming data plate to the newly “overhauled” engine.  I have one that I take care of in a Comanche.

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