How often do engines make it past TBO?

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checkmysix
Just curious to hear experiences from owners on how long your single piston aircraft engines have made it either to or past TBO. Most of the planes for sale have what are called run out engines either close to TBO or way past it. With a new Lycoming or TCM engine costing north of 40K, it makes sense to minimize risk in the purchase process.
 
3 of my planes I bought with low time engines and never ran them out (although the 310 engines were past the 12 year calendar TBO and I did replace some dried out seals), although I did put cams and tappets in my Travelair. The 1340 on the Ag Cat I took 75 hrs past the 1200 hr TBO and sold it at the end of the season.
 
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I bought the cherokee with the O360 engine at 2200 hrs with one cylinder overhauled. Ran it to 2800 hrs, overhauled a second cylinder during that time. Only reason I went ahead with the overhaul at 2800 hrs was the prop strike. the insurance paid for the teardown, the R&R and the new prop, so I paid the rest of it including all new hoses and cylinders.
 
Still looking Ben?;)

Depends on how the engine was run.

200-500 hours per year, conscientious owner-pilot from day 1: bet on past TBO no problems

300+ hours per year, club environment: Probably makes TBO or beyond

500+ hours per year, line-dog/training/freight environment: lucky if TBO

25 hours per year, or "lost medical" and let sit: unlikely
 
Ive not been in aviation long enough to have first hand knowledge. But many on the COPA forum have gone well beyond TBO. The longest i know of is Rick B (a member here as well) went 3500 and just had his overhauled. Of course Rick and many others run LOP.

My hangar neighbor has 2700 on his SR22 and he has replaced his cylinders at 2300 he feels he has more engine life to go. I've flown in his plane and it runs strong.

Really depends on how you run it.

I really hope you buy a plane Ben. I've followed some of your posts. Its a big decision for sure. But at some point you just do it. It took me 5 weeks to find the plane i wanted, have it inspected and bought.

My mistake was not getting the plane i really wanted as i was trying to save money amd i was not het Instrument rated. Now i am selling a plane i just bought earlier this year and buying another.

In any event. Its how you run the motor. Good luck.
 
Assuming you do oil analysis, borescope it every annual, I don't see going past TBO a problem.

BTW, can someone point me to a good technical article on what to look for in oil analysis reports, and what high levels of a metal can mean, etc?
 
EminiTrader said:
Its a big decision for sure.
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is it really? You can buy a decent airplane for the price of a used pickup truck. Anyone can find a reason not to buy a plane. Some people find not buying a plane is a hobby unto itself.
 
In general engines that are flown regularly will have a much greater chance of reaching TBO than the average privateer who flies occasionally. To offset that the 135 operators who rack up hours can't run past TBO because of regulations while privateers can opt to fly poorly maintained engines until the crank falls out. If you run your engine at the factory's ideal of 40 hours per month you'll probably see TBO. If you fly 15 hours a year you probably won't.
 
Stewartb said:
In general engines that are flown regularly will have a much greater chance of reaching TBO than the average privateer who flies occasionally. To offset that the 135 operators who rack up hours can't run past TBO because of regulations while privateers can opt to fly poorly maintained engines until the crank falls out. If you run your engine at the factory's ideal of 40 hours per month you'll probably see TBO. If you fly 15 hours a year you probably won't.
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please provide at least one example....:dunno::yikes:

BTW....cranks typically do not fail within a TBO period and yes even the bad ones with the horrible ADs. They can last 6,000-10,000 hrs.....and when replaced are done so due to wear....not catastrophic failure.:rolleyes:

TBO?.....ok, lets have a discussion about the physics of failure and why an engine would need to be overhauled.:wink2:
 
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It was just a comment. My own in flight engine failure came from a rod spitting through the case and beating a large hole in the side of a 900TTSN engine. Most private owners will condemn their engines due to corrosion issues, not time or age issues. I've replaced a couple myself. My 135 operator friends' engines are usually running fine when they have to come off. If you spend much time around many airplanes the trend is unmistakable.
 
Stewartb said:
It was just a comment. My own in flight engine failure came from a rod spitting through the case and beating a large hole in the side of a 900TTSN engine. Most private owners will condemn their engines due to corrosion issues, not time or age issues. I've replaced a couple myself. My 135 operator friends' engines are usually running fine when they have to come off. If you spend much time around many airplanes the trend is unmistakable.
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Ok....but, clearly not a crank failure....and much sooner than the recommended TBO.:rolleyes:

again.....I bet most here don't even know the major activity involved in an overhaul. It isn't what most think.....it's inspection, not parts replacement. :nono:
 
Going past TBO is not a big deal in most cases. I ran the 310 engines 400 past TBO. Could've topped the left side and kept going, but the double overhaul made sense at that point in time.

The real question is how it's been cared for. While overhaul is an inspection, obviously some things will get replaced, such as bearings and things that fail inspection. :)

This set of engines I'm hoping to run at least 1,000 past TBO.
 
Let's define going past TBO? If the Crank, rods, and mains make it does that count? Or are we saying that the valve covers are never off from birth to TBO? I find a lot of these conversations misleading for these reasons. How many times have I read that "my engine went 3,000 hours before overhaul" only to find out it was topped twice, numerous seals, and other repairs during its life. The total cost of which easily exceeded an overhaul.
 
Ask a flight school, or look at some 172s and PA28s for sale, plenty go well past OH.
 
Both aircraft I've owned went past TBO. The first geared engines I was 150hrs over when I sold it. The Aerostar I bought with 300hrs over TBO engines and flew another 100hrs before the oil consumption on the left one started getting pretty heavy.
 
James331 said:
Ask a flight school, or look at some 172s and PA28s for sale, plenty go well past OH.
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The 172P I took my checkride in was well beyond TBO. IIRC was around 3300hrs.:rolleyes2:

...come to think of it, Are they allowed to go beyond TBO in a 141 program?
 
teejayevans said:
Assuming you do oil analysis, borescope it every annual, I don't see going past TBO a problem.

BTW, can someone point me to a good technical article on what to look for in oil analysis reports, and what high levels of a metal can mean, etc?
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Not aviation, but LOTS of really good oil information at "bobistheoilguy.com."

Also a very good aviation oil related section of Harry Fentons document to which I posted a link in about post number 3 or 4 in this thread.
 
Alexb2000 said:
Let's define going past TBO? If the Crank, rods, and mains make it does that count? Or are we saying that the valve covers are never off from birth to TBO? I find a lot of these conversations misleading for these reasons. How many times have I read that "my engine went 3,000 hours before overhaul" only to find out it was topped twice, numerous seals, and other repairs during its life. The total cost of which easily exceeded an overhaul.
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YOU CAN SEE THE FOREST FROM THE TREES!!!!!!


Currently looking at an O-360-A1F6D that was last overhauled in 1989, that is more than double the 12 year calendar TBO. The engine has roughly 1,200 hours since that overhaul but a total of ~3,400 hours since brand new in 1977.

This engine has had since 1989:

One brand new cylinder (#4 was found cracked last year). All the others appear to be original from 1977 with them overhauled in 1989 making them (3 of the 4) second run cylinders.

New Fuel Pump
New Exhaust (Not the risers but the collector)
All new intake rubbers and intake gaskets
New spark plugs
Several Magneto IRANs
Several Vacuum pumps
One alternator
New prop-to-crank o-ring
New crankcase nose seal (seals the crankshaft opening in the front of the crankcase)
All new valve cover gaskets
New skytech starter
(I think a set of rubber engine mounts but can't remember for sure)
One new throttle cable
(I think a new mixture cable)

It could use a set of spark plug wires. Some of the baffle springs look pretty corroded. The exhaust studs on the old old cylinders don't even look terrible as one would expect.
 
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First run engines will almost always make it beyond TBO. Many make 3000 hours if the owners let them. It does depend on a lot of things though. Some owners/mechanics do "running rebuilds", replacing whatever is causing a problem. Im more of a doitrightordontdoitatall guy, although I'll admit in the short run it costs more. New engines are safer also, fewer catastrophic failures is what I believe, though I admit I cant prove it.
 
coloradobluesky said:
First run engines will almost always make it beyond TBO. Many make 3000 hours if the owners let them. It does depend on a lot of things though. Some owners/mechanics do "running rebuilds", replacing whatever is causing a problem. Im more of a doitrightordontdoitatall guy, although I'll admit in the short run it costs more. New engines are safer also, fewer catastrophic failures is what I believe, though I admit I cant prove it.
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80% is just dumb luck in my opinion. The engine listed above has dodged every crankshaft AD to date. Had the crank or engine been replaced with new at anytime, it may be a different story.

There is a guy on CPA that has a T182T with an engine at 11 years and under 1800 hours, that stuck a valve and broke the side of the lifter off, cracked and bent the pushrod and tube requiring teardown to replace the lifter. He noticed an odd EGT after start but thought it was running ok on pre-flight then flew it about 45 minutes and landed at avionics shop and discovered oil leaking.
 
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Alexb2000 said:
Let's define going past TBO? If the Crank, rods, and mains make it does that count? Or are we saying that the valve covers are never off from birth to TBO? I find a lot of these conversations misleading for these reasons. How many times have I read that "my engine went 3,000 hours before overhaul" only to find out it was topped twice, numerous seals, and other repairs during its life. The total cost of which easily exceeded an overhaul.
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You can continue to repair any engine until you wear out the data tag, and never overhaul it. and many A&Ps do.
 
What makes me laugh, is when a buyer thinks it must be overhauled to be considered worthy of the priced asked. When in fact the engine could have been disassembled cleaned inspected, and repaired as necessary, and returned to service as a repair. and the Time Since Major Overhaul continues.

As I have said many times before, Every engine is a study in its self.
 
coloradobluesky said:
First run engines will almost always make it beyond TBO. Many make 3000 hours if the owners let them. It does depend on a lot of things though. Some owners/mechanics do "running rebuilds", replacing whatever is causing a problem. Im more of a doitrightordontdoitatall guy, although I'll admit in the short run it costs more. New engines are safer also, fewer catastrophic failures is what I believe, though I admit I cant prove it.
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I'd like to see tear down reports on all engines made public. That would require the manufacturer manufacture a well made product. or get a lot of bad press.
 
Checkout_my_Six said:
TBO?.....ok, lets have a discussion about the physics of failure and why an engine would need to be overhauled.:wink2:
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#1 reason? Performance. I've had a couple of opportunities to replace engines that were airworthy but getting well worn. Not broken, just not new. Compressions good but oil consumption up. Oil seeps easy to find. Replace with a reman or better yet, a custom overhaul to new tolerances? It's like going from a tired old Buick to a new sports car. Zoom zoom. Better starting, better power, better fuel efficiency, and the king of reasons, better clearance over obstacles at my normal strip. Performance drives my choices.
 
Stewartb said:
#1 reason? Performance. I've had a couple of opportunities to replace engines that were airworthy but getting well worn. Not broken, just not new. Compressions good but oil consumption up. Oil seeps easy to find. Replace with a reman or better yet, a custom overhaul to new tolerances? It's like going from a tired old Buick to a new sports car. Zoom zoom. Better starting, better power, better fuel efficiency, and the king of reasons, better clearance over obstacles at my normal strip. Performance drives my choices.
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I would say it's a close race between performance and people believing they need an overhaul to regain what they have lost, and taking into consideration that economically, they are better off spending twice the money and having 3/4s of that reflect as a residual increase in aircraft value, than if they spend half of that returning the engine to good running condition with everything in spec and not being able to apply any of that to residual market value. "The Market" is rigged to be most profitable.

If you are looking to sell the plane, the choice is obvious, put on a Factory Reman/Rebuild or a Boutique shop engine that has a nation wide name behind it. That will give you the greatest return for your dollar spent and give you good marketability. The only thing better for marketability is Factory New, but they usually don't bring their difference in cost.

If you are looking to use the fuselage for your coffin though (or any amount of time that will take you significantly past TBO;)), then you can take advantage of the cost savings of repairing the engine on condition. Engines are an amalgam of components that all wear at different rates. At TBO only a few of your parts are worn out, and in an overhaul typically a lot of perfectly good parts get wasted, or squirreled away by the shop to fix something later. You can greatly improve your 6000 hour costs by using up and replacing the parts as they wear. Regular oil analysis gives us the tool to make that a safe approach.

The negative to this method is increased frequency in major evolutions, you work on the engine more often, however what you end up spending overall will be dependent on the labor costs.
 
Tom-D said:
That's just you. If you didn't trust it, why did you fly it?
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If I put a significant amount of new parts in an engine, I am leery of it until I've put it through some trials and tested the parts thoroughly. Trust is an issue that varies in level. Just because I don't trust the parts supply chain completely anymore doesn't mean I'm paranoid about it. I just hedge my bets with my operating profile during the trials. Typically the engine has at least a few runs on the stand so any major immediate defects in quality will hopefully have let go by then and my odds of catastrophic failure are greatly diminished. So no, I don't trust an engine for a few hours, but that doesn't extend to the level of no being willing to take it flying.
 
We flew our Warrior's 150hp O-320 to 2500 hours before we replaced that motor with a 160hp motor. Reason for overhaul: abundance of caution and desire for ten more mighty horses.

There was nothing at all wrong with that motor at 2500 hours, had it been just my plane I would have flow it to 3000 hours without a worry in the world.
 
JHW said:
is it really? You can buy a decent airplane for the price of a used pickup truck. Anyone can find a reason not to buy a plane. Some people find not buying a plane is a hobby unto itself.
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Jeff. Point taken. I bought a newer aircraft so a little more than a used pickup. I dont make the big money like some of you guys do. So it was a big decision for me. But it was an easy decision that i am quite happy i made.
 
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