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rebuild (zero time) engine or overhaul the engine?


sekomel

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hi everyone

hope this message finds you very well..

I recently bought a mooney m20j mse, 1993..she is very clean and good condition, no issues so far when I fly with her from any perspective..engine condition is good, I just did the compression ratio check and figures were well above the limit..I am so happy with her current condition..(I know lycoming advise

engine is at 1.050 hours - very low..but my main concern is the engine never overhauled since 1994..

engine is lycoming IO-360-A1B6. 

people around me (especially my technician) does not advise to rebuild or overhaul the engine as he is happy with the current condition but I do want this especially for my main future project (circumnavigate the world).

I started to work on my budget and the difference is between rebuild or overhaul the engine is around 10k $ so I might be able to go for the best option as I saved some money.

my question is, what would you choose? what are the advantages or disadvantages that I have you think? 

I am totally open any ideas/advise you have..

thank you all in advance,

sekomel

 

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For  a lot of overwater flight I’d want a zero timed motor, but I wouldn’t leave until I had 100 hours on it.

If I had the money to spend on a zero time motor, I’d want roller tappets, and independent mags.

Other than cost there is no disadvantage of a factory zero timed motor.

Edited by A64Pilot
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Lookslike on Airpower, where I bought my factory reman several years ago, the price difference is about $4500.  https://www.airpowerinc.com/productcart/pc/engines.asp?searchParm=IO360-A1B6&catID=33

Also, when I got mine there was a very small upcharge for roller tappets.

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I think I'd be much more comfortable with a 1000-hour engine that's running well and has no known issues than a newly-overhauled engine.  I'd certainly do a compression and borescope before departing for a RTW trip, but even a new overhaul that I quickly flew 100 hours on would be less comfortable for me than a 1000-hour engine that's been perfect for years.

The A3B6 already has independent mags.  I think a factory new Lycoming is back to flat tappets with some sort of diamond coating.

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I haven't seen any compelling evidence that a factory-rebuilt "zero time" engine is more reliable than a reputable overhaul.

A factory rebuilt engine is assembled from a combination of new and used parts.  The latter must meet new tolerances, but they're still used (which is arguably a good thing: used parts have survived at least some time in service).  So understand that what you get for the extra cost vs. a traditional overhaul from a reputable shop is just the knowledge and expertise of the factory itself in assembling the engine.  You can decide for yourself what that's worth, but I'm not sure the folks in the Lycoming shop have anything on well-known, non-factory shops.  You certainly don't have to look hard to find stories of issues with factory rebuilds.

If that bugs you, you can go factory new instead of factory-rebuilt.  No used parts.  But now you're looking at roughly twice the cost, and again, it's not clear new parts are actually more reliable than used.

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4 minutes ago, Vance Harral said:

I haven't seen any compelling evidence that a factory-rebuilt "zero time" engine is more reliable than a reputable overhaul.

A factory rebuilt engine is assembled from a combination of new and used parts.  The latter must meet new tolerances, but they're still used (which is arguably a good thing: used parts have survived at least some time in service).  So understand that what you get for the extra cost vs. a traditional overhaul from a reputable shop is just the knowledge and expertise of the factory itself in assembling the engine.  You can decide for yourself what that's worth, but I'm not sure the folks in the Lycoming shop have anything on well-known, non-factory shops.  You certainly don't have to look hard to find stories of issues with factory rebuilds.

If that bugs you, you can go factory new instead of factory-rebuilt.  No used parts.  But now you're looking at roughly twice the cost, and again, it's not clear new parts are actually more reliable than used.

What difference is there in the reliability of the work done by an overhaul shop versus the factory?   I've heard stories of both, are there stats?    

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5 minutes ago, Boilermonkey said:

What difference is there in the reliability of the work done by an overhaul shop versus the factory?   

That's literally the $10,000 question.

I don't know of any good statistical data on this, unfortunately.  Just anecdotes.

Even if you had statistical data, it's hard to argue it would be meaningful.  No one here is buying a fleet of engines, and that's the only thing statistical data would really be valid for.

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27 minutes ago, Ragsf15e said:

As soon as you add in a new case, cam, crank (if they are found out of limits during OH) and all the accessories, factory reman is pretty close to the same (or maybe less) than the reputable OH to new limits.

My understanding - based purely on internet lore, not any actual research - is that you have to send your core to the factory in order to purchase a factory reman (so they can use your parts in some future reman).  It was also my understanding there is an upcharge from the factory if your core's crank or case is bad on arrival, as they won't be able to re-use it.  If that's true, you'll pay extra for a bad crank or case either way, so it's not correct to say that a factory reman is nearly the same price vs. overhaul if you need a new crank and/or case.

If that understanding is incorrect, please educate me.

I believe the cam is nearly always replaced by reputable overhaul shops, and not particularly expensive in the grand scheme of things.

Edited by Vance Harral
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Probably the only thing the older rebuild will have issues with is leaks.   You can replace the return hose on the head drains with new.   Put silicone gaskets on the valve covers and just run it for awhile.  If you like you can just replace/rebuild cylinders as needed.   Bottom ends of engines rarely need things unless the motor makes metal.   They just get leaky.

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2 hours ago, A64Pilot said:

For  a lot of overwater flight I’d want a zero timed motor, but I wouldn’t leave until I had 100 hours on it.

If I had the money to spend on a zero time motor, I’d want roller tappets, and independent mags.

Other than cost there is no disadvantage of a factory zero timed motor.

My sentiments exactly. I am making the same decision but not go around the world with it, just over to the Bahamas and over mountains, but the infant mortality risk concerns me a little. I want at least 100 hours on a factory reman before I do that, better yet 200.

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It depends on who does the overhaul and how it is done. You can easily get 75K into an overhauled IO-360 with ported and polished cylinders, cryogenic crank, cam rods, pinned main bearing bosses, etc all put to new tolerances, balanced to 1/2 gram. No matter what the engine is far better than factory, but also, no matter what, it is not a zero time engine. On the other hand you can do the overhaul to overhaul tolerances, replacing only the parts required and no matter what it also an overhauled engine and it will be cheaper than factory or the guys listed below. So asking if an overhaul or a factory zero time is better cannot be answered unless one knows what is the scope of the overhaul. Once you know the scope then you can compare it to factory and make a decision. 

For my money there is only 4 shops I would send an IO-360 to for overhaul and none of them are cheap but all better than a factory engine:

Gann Aviation, LaFayette, GA

Penn-Yann, Penn Yann, NY

Ly-Con, Visalia, CA

Victor Aviation, Palo Alto, CA

 

My personal view is if one of the above shops don't overhaul it, I'll buy a factory zero time. 

Opinion only.

By the way, as someone who used to ferry overwater, the above advice is sound. Your problem will not be fuel capacity, but oil capacity. Make sure the oil in the sump has the range to get you there. That means a well broken in and stable engine.

 

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I had Penn Yan overhaul my IO360 2 years ago. That was good. They used new Lycoming cam and lifters in the rebuild. That was bad. The cam failed @ approximately 200 hrs, necessitating a tear down and replacement. Penn Yan warranted the engine and freight. It took about 5 mos for them to reimburse me for labor, prop flushing, and governor overhaul, all due to metal from the failed cam lobe. They said they were waiting on reimbursement from Lycoming. 
I think there is a huge problem getting the correct steel for these components. Maybe machining errors too, but it seems to point to metallurgy. 
 

Robert

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2 hours ago, GeeBee said:

 

For my money there is only 4 shops I would send an IO-360 to for overhaul and none of them are cheap but all better than a factory engine:

Gann Aviation, LaFayette, GA

Penn-Yann, Penn Yann, NY

Ly-Con, Visalia, CA

Victor Aviation, Palo Alto, CA

 

 

 

Interesting you listed Gann, it’s a rather small shop isn’t it?

I know a lot of the Maule people like Gann, I had figured largely because it’s a Georgia shop. I believe the parallel valve Lycoming’s he uses new cylinders, but has the angle valve cylinders rebuilt, that seemed odd to me.

 

Oh, I believe the OP is in Turkey, I’m not sure what his availability is of those shops, but assume there is a Turkish dealer that can get him a Factory overhaul.

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3 hours ago, jlunseth said:

My sentiments exactly. I am making the same decision but not go around the world with it, just over to the Bahamas

Not even close to similar, you’re only out of gliding range for about 10-15 minutes between Florida and the Bahamas. I only point this out bc I want to emphasize how easy this flight is for those on the fence for this reason. It’s a great adventure with IMO only a moderate risk. Less risky in many ways than flying around highly populated cities. 

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3 hours ago, Vance Harral said:

My understanding - based purely on internet lore, not any actual research - is that you have to send your core to the factory in order to purchase a factory reman (so they can use your parts in some future reman).  It was also my understanding there is an upcharge from the factory if your core's crank or case is bad on arrival, as they won't be able to re-use it.  If that's true, you'll pay extra for a bad crank or case either way, so it's not correct to say that a factory reman is nearly the same price vs. overhaul if you need a new crank and/or case.

If that understanding is incorrect, please educate me.

I believe the cam is nearly always replaced by reputable overhaul shops, and not particularly expensive in the grand scheme of things.

Yeah, I think they generally want a “running” engine and will look at the things you mentioned.  However I’ve heard they are also fairly reasonable when they find things amiss inside the cores they receive.  A local flight school sent one in and then got a bill for the crank, but was able to negotiate the charge down a reasonable amount.  My knowledge of all this is pretty much here-say too...

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22 minutes ago, Robert Tanner said:

all due to metal from the failed cam lobe. They said they were waiting on reimbursement from Lycoming. 
I think there is a huge problem getting the correct steel for these components. Maybe machining errors too, but it seems to point to metallurgy. 

I have been pondering this chicken vs egg scenario, and your experience may help, but how did the lifter faces look? Does lifter destroy cam every time or does cam ever destroy lifter? 

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I had Penn Yan overhaul my IO360 2 years ago. That was good. They used new Lycoming cam and lifters in the rebuild. That was bad. The cam failed @ approximately 200 hrs, necessitating a tear down and replacement...
I think there is a huge problem getting the correct steel for these components. Maybe machining errors too, but it seems to point to metallurgy.

Now you are making me nervous, I had my IO360 overhauled 2 years ago as well, just changed the oil, so far no metal after 229 hours.
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33 minutes ago, A64Pilot said:

Interesting you listed Gann, it’s a rather small shop isn’t it?

I know a lot of the Maule people like Gann, I had figured largely because it’s a Georgia shop. I believe the parallel valve Lycoming’s he uses new cylinders, but has the angle valve cylinders rebuilt, that seemed odd to me.

 

Oh, I believe the OP is in Turkey, I’m not sure what his availability is of those shops, but assume there is a Turkish dealer that can get him a Factory overhaul.

Carlus will give you anything you want. If you want all new Lycoming cylinders, he'll put them on. He is small shop because he only allows himself to build up engines. That said, the last engine he built for me ran 8% over rated power and was so well balanced that when I had a dynamic prop balance done (fixed pitch), there was nothing to be balanced out.

 

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8 hours ago, Vance Harral said:

I haven't seen any compelling evidence that a factory-rebuilt "zero time" engine is more reliable than a reputable overhaul.

Byron and I got engines around the same time circa 2012. He got factory overhaul, I got factory reman. His engine was toast at 500 hours. Mine’s already past a thousand and just has high oil consumption but good compressions and borescope. He needed a full overhaul. 
 

He’s jetdriven or whatever he calls himself since the sex change operation.

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It's hard to imagine any of us could give advice on a good engine shop for overhauls in Turkey :)

As such, I'd suggest going the rebuilt engine route, unless OP knows of a trusted engine shop locally.

I think most of us would actually still recommend sticking with the motor without an overhaul.  I can't think of any catastrophic failures from normal wear that an overhaul would specifically prevent.  As @Yetti alluded to, they just get leaky, stinky and less efficient over time.  That's probably true for all of us as well :)

 

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9 minutes ago, 201er said:

Byron and I got engines around the same time circa 2012. He got factory overhaul, I got factory reman. His engine was toast at 500 hours. Mine’s already past a thousand and just has high oil consumption but good compressions and borescope. He needed a full overhaul. 
 

He’s jetdriven or whatever he calls himself since the sex change operation.

I'm happy for you and sad for Byron, but the history of two individual engines is not evidence that a factory reman is generally more reliable than an overhaul.  That's what makes these decisions difficult, there doesn't seem to be much data other than individual anecdotes.  Plenty of folks happy with overhauls and plenty of folks unhappy with factory reman, opposite of your and Byron's experiences.  Hard to guess what any particular individual's experience is going to be.

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6 hours ago, Vance Harral said:

My understanding - based purely on internet lore, not any actual research - is that you have to send your core to the factory in order to purchase a factory reman (so they can use your parts in some future reman).  It was also my understanding there is an upcharge from the factory if your core's crank or case is bad on arrival, as they won't be able to re-use it.  If that's true, you'll pay extra for a bad crank or case either way, so it's not correct to say that a factory reman is nearly the same price vs. overhaul if you need a new crank and/or case.

If that understanding is incorrect, please educate me.

I believe the cam is nearly always replaced by reputable overhaul shops, and not particularly expensive in the grand scheme of things.

The factory has made it very clear they do not charge back for bad components inside of an operable engine. None of the other shops guarantee this. When you open it up, you own it, and if it’s a $6000 case or a $4000 crank and you add that to the cost

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Just now, Vance Harral said:

I'm happy for you and sad for Byron, but the history of two individual engines is not evidence that a factory reman is generally more reliable than an overhaul.  That's what makes these decisions difficult, there doesn't seem to be much data other than individual anecdotes.  Plenty of folks happy with overhauls and plenty of folks unhappy with factory reman, opposite of your and Byron's experiences.  Hard to guess what any particular individual's experience is going to be.

I fully understand that. I’m just saying this was coming from the factory around the same year and what I know about first hand.

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