Engine age vs hours

Roy Lee Kinser Jr

Roy Lee Kinser Jr

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lkinser
I feel like I'm beating a dead horse with another engine question thread, but I can't seem to find something that speaks to this specifically.

I'm looking at buying an older Cherokee with a Lycoming O-360-A3A engine. The aircraft itself is nearly perfect for my mission. 3100 AFTT and 750 SMOH. The issue is the date of that overhaul, which was 19 years ago, far exceeding the 12 year suggestion from Lycoming.

From reading similar threads, I know folks take engines beyond that recommendation, but I'm uncertain how common that is and certainly unsure as to how fraught with complications that is. So I'm curious, are guys out there really taking running engines out of service for OH due to years or is that just a suggestion that most brush off? Has age been the source of issue for others out there?

Again, sorry for beating a dead horse, I just can't seem to decipher the right mix of low airframe hours, low OH age, has all the avionics needed, NDH, etc etc.... it seems like that is impossible and I'm going to have to compromise somewhere.
 
Have a good prebuy done, could be a great engine, could be only good for a core, needs a pre buy. Despite the old wives tales planes don’t fall apart if they hang out in a nice hangar or the like.
 
That's an average of about 40 hours per year, which is not horrible for utilization. The main enemy of engine longevity is corrosion due to lack of utilization. Check for evidence of internal corrosion in the pre buy and take it from there, using the 19 year old engine as a bargaining chip.

My inherited mid time engine made 25 years before needing a MOH. A few slack years on my part probably hastened its demise.
 
Roy Lee Kinser Jr said:
I just can't seem to decipher the right mix... etc etc....
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Unfortunately, there is no right mix. As stated, determine your "mix" with a good pre-buy and discuss with current or future mechanic.
 
Where has it lived? What's the engine's history before 19 years ago?
 
Short flights or ground-running only is really bad. We had to replace a 277-hour Lyc due to the owner's doing occasional ground runs instead of flying the thing.
 
Stewartb said:
Where has it lived? What's the engine's history before 19 years ago?
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miss-cleo.png
 
Assuming a factory new pristine engine that was immaculately pickled, will have issues with gadgets and seals failing after 2 decades.

19 years is pretty edgy on a used engine. Any time from it is a gift.
 
NordicDave said:
Assuming a factory new pristine engine that was immaculately pickled, will have issues with gadgets and seals failing after 2 decades.

19 years is pretty edgy on a used engine. Any time from it is a gift.
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huh?

"Good sir, I'll over you 1/3 your asking price as its obvious your gadgets and seals surely are blown" lol
 
James331 said:
huh?

"Good sir, I'll over you 1/3 your asking price as its obvious your gadgets and seals surely are blown" lol
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Ha! Right? Engines getting past 2 decades are going to have seeping and leaking issues at best. I believe engines should be changed “On condition”, but eventually time just catches up.
 
NordicDave said:
Ha! Right? Engines getting past 2 decades are going to have seeping and leaking issues at best. I believe engines should be changed “On condition”, but eventually time just catches up.
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My engine lower hadn’t been split in 52 years. And it hadn’t flown much in the last 20. It had no seal or gasket issues. It hadn’t even been pickled. I flew it for 2 years with no issues before finally breaking it open simply because I felt I was pushing my luck rather than any issue.
 
It's a total gamble. Unless it's used as a training aircraft or in some other business use very few airplanes reach TBO before the 12 year mark. I'd be more concerned over how much it's been used the past few years than how it was used 5+ years ago. Sometimes you win and don't have any problem, sometimes you loose and that's why you see so many unused ramp queens. Whether there is actually any merit to it, my experience and many others locally have noticed Continental's seem to stand up to age better than Lycomings. Granted that's a pretty small sample size compared to the overall fleet.

Cylinders and cams are usually what dictate a needed overhaul. Cylinders can overcome a little rust pitting and still run strong for many years without continued demise. Cams on the other hand will only get worse once rust pitting has started which slightly favors continental's engine design over Lycoming.

A good bore scope will tell you a lot as to the condition you will likely encounter on the inside of the engine as well unless they are chrome cylinders in which case they shouldn't rust. There is really no good way to inspect the inside of the engine without major work which most people would not sign up for when selling an aircraft.

My engine is 30+ years old and on top of that sat for 17+ years and luckily has been a champ. My dad has bought several old Luscombes with their original engines that had sat for many years and been fine. On the other hand they have had several RV's that have come through their shop that were purchased after extended periods of sitting and needed a major overhaul with only 300 hours due to worn cam lobes and rusted cylinders.

There is no guarantee in aviation. These are mostly old airplanes with unknown past so it's best to shop under budget so you can afford the potential surprises.
 
These filters have about the same number of hours on them. One came from a 51 year old Lycoming O320 with around 1800 total time , and the other from a 25 year old O-470 with about 900 since factory reman. Both airplanes use autogas extensively. Which one came from which engine?

We have had the O320 for about 14 years, it has never had a single issue other than plenty of "feel good maintenance" replacing old carburetor, hoses, wires, mags, spark plugs, rubber bits, starter, etc. When my brother put a powerflow exhaust on it he elected to replace a cylinder with a overhauled one due to exhaust port flange erosion. Its been a great engine for us. I am getting a little fed up with the oil consumption so I'm debating on just putting 4 brand new cylinders on (and careful examination of the cam/lifters in the process) or just yanking the whole thing apart and IRAN at the same time.

(Note: Overall the filter on the left had more junk in it than the one on right)

upload_2019-9-20_6-44-42.png
 
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The engine we replaced last winter was at 19yrs and 2250hrs. It was stone cold reliable right up until the last six months when it started talking to us.

As others said, get a good pre-buy, buy it right, have the reserve in place for an overhaul, and fly it until it starts to talk to you.
 
O-360's are bullet proof. Mid time and 19 years is nothing. How much has it been flying per year the last 5 years? Have they had oil anyalsis done you can look at? Like other have said, get a prebuy and have the filter cut open and pull the suction screen. Also have the cylinders scopped and look carefully at the exhaust valves. Check to see how strong the oil prrssure is.

The biggest problem is you will not be able to see the bottom end but if you're not seeing ferrous metal in the filter or the screen and the oil pressure isnt weak (which can be adjusted anyway) you likely will be fine.

Don't let that engine stop hinder the deal, if it checks out fly the fool out of it!
 
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How do you pre-buy inspect a cam and lifters? That's where age and inactivity will show in a Lycoming engine. The stated times may be a concern for a plane in a humid area and less of one in a dry climate. Factory first run or third run field overhaul with reground cam and followers would be a consideration for me. All you can do is gather the information and roll the dice. The variable is how much you want to bet on it.
 
I think it depends. I sold my Six with a fresh mid-time engine (+600 hrs)....after two years in San Diego then to Texas with minimal use....the cam was trash and needed an OH. The last owner contacted me. I always ran CamGuard and got clean oil analysis. It didn't fly but once a month but was super clean for me. Once it sat....in San Diego....it was trashed. So IMHO....age isn't much the issue vs. the environment (warm & humid is horrible) and operating conditions.
 
Stewartb said:
How do you pre-buy inspect a cam and lifters?
...
All you can do is gather the information and roll the dice.
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Yep. I just got to replace a cam in a 200SMOH engine.
 
Generally an engine that old is going to have a corrosion issue, but I know of one Lycoming that went from new in 1977 to 2015 with no issues.
 
Clip4 said:
Generally an engine that old is going to have a corrosion issue, but I know of one Lycoming that went from new in 1977 to 2015 with no issues.
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no....no...and no.....here's my engine since 2004 OH (~1,000 SMOH). Here's the outside during the top overhaul. Once open....pics of the crank and cam and lifters....of the "old"engine. In all fairness....this one is a TCM....but, for Lycoming it just depends. A general statement doesn't work.
 

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19 years? My engine is at 33 years old and going strong *knock on wood*. I cut open every filter, get oil analysis done at every oil change and the engine doesn't leak a bit of oil. I add a quart every 15 hours and compressions are excellent. 700 hours on the engine when I bought it. I've put over 200 hours on since buying it.

I think "it depends" is accurate. Anyone telling you it WILL have failing seals is full of it.
 
Clip4 said:
Generally an engine that old is going to have a corrosion issue, but I know of one Lycoming that went from new in 1977 to 2015 with no issues.
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I know a 1965 172 still running on its original O-300. Nearing its 1800-hour TBO. It leaks.
 
I don't think it matters what brand the engine is, cams/lifters are a crapshoot, with Lycoming leading in failures here. The great part is spalled lifters and cams usually don't end with the airplane suddenly becoming a glider. Unfortunately repair is always costly.
 
NordicDave said:
Ha! Right? Engines getting past 2 decades are going to have seeping and leaking issues at best. I believe engines should be changed “On condition”, but eventually time just catches up.
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That has not been my experience.

Frankly I’d be more concerned with how it was flown than years since TBO.

Again a good prebuy is the alpha and omega of the conversation.
 
If you’ve budgeted to replace it at any time, it doesn’t matter. Any engine can die tomorrow. The joy of ownership. LOL.
 
denverpilot said:
If you’ve budgeted to replace it at any time, it doesn’t matter. Any engine can die tomorrow. The joy of ownership. LOL.
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Any aircraft can also break, probably shouldn’t buy one unless you budgeted to replace it at any time?

Seems with many of these reserves it gets to the point even a somewhat well off person can’t even afford to own a skateboard.
 
James331 said:
Any aircraft can also break, probably shouldn’t buy one unless you budgeted to replace it at any time?

Seems with many of these reserves it gets to the point even a somewhat well off person can’t even afford to own a skateboard.
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I said budgeted / maybe “prepared” is a better word.

It’s kinda like planning for my crappy transmission to go out on my Yukon. It’s not a matter of “if” with that thing. LOL.

Same with airplane engines.
 
denverpilot said:
I said budgeted / maybe “prepared” is a better word.

It’s kinda like planning for my crappy transmission to go out on my Yukon. It’s not a matter of “if” with that thing. LOL.

Same with airplane engines.
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To a point, I just take it as it comes and plan on doing a OH at TBO
 
James331 said:
To a point, I just take it as it comes and plan on doing a OH at TBO
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Most of us do, but knowing what you’ll do if it blows up at half of that, at least some sort of plan, is good. I know a three way partnership that imploded and the plane sat for three years when they had no plan.

In this case, half time engine, very old, no history on if it sat, no description if it was in a dry or wet climate... who knows? Could run great, could trash itself from corrosion. Can look at what you can look at, and go from there — with a plan for major repairs or replacement in your head.

That’s all I’m really warming about. If the question is “Can I absolutely get away with not dropping $30K tomorrow?” ... the answer is always no. The engine is basically a consumable.
 
My PA28-140 with O-320 was last overhauled in 1982, just turned 1000 hrs a couple of weeks ago. It had about 800 hrs on it time I bought seven years ago. Log book shows some years it was flown 40-60 hours, some years just 2-4. The previous owner had flown it 20 or more hours per year for the 5 plus years they had owned it. My A&P and I pulled a cylinder to repair a broken exhaust stud a couple years ago and everything inside as far as piston and what I could see of crank still looked new.

I'd get a good pre-buy an see if any red flags come up. No guarantee on anything, but an engine past the 500 hr likely had anything failed and replaced if it was defective from the rebuild.
 
denverpilot said:
If you’ve budgeted to replace it at any time, it doesn’t matter. Any engine can die tomorrow. The joy of ownership. LOL.
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Actually, it does matter in the sense that there's loss of use. If the engine died and you've got plenty of money it's not like you can get a new one via Amazon Prime.
 
asicer said:
Actually, it does matter in the sense that there's loss of use. If the engine died and you've got plenty of money it's not like you can get a new one via Amazon Prime.
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True. Hadn’t really considered it but I know someone who waited many months for a crate engine brand new for a Skyhawk. Lovely after the replacement, super smooth and ran great. He’d been through the wringer on “well recommended and well known” rebuild shops who did a shoddy job and was tired of it. Airplane flies a LOT as a trainer. Engine replacements done every few years. No grass growing under that particular Skyhawk. :)
 
I fly an O-320 that’s at about 1100 hrs since new in 1971. Bore scoping the cylinders shows a little corrosion on three of four but oil consumption is negligible and nothing is ever found on the filter. It’s not dry as a bone but it doesn’t drip. I’m going to run it for a while longer. Mags and carb are newer.
 
I have an o-360-A4A that was majored 28 years ago, with 706 hr on it.... and if runs GREAT!... no issues at all.... Since I purchased the plane 4 years ago have flown it about 130ish hours, and it is showing no signs of problems.... run it, change the oil more often, and love it. All will be well in the universe.
 
asicer said:
Actually, it does matter in the sense that there's loss of use. If the engine died and you've got plenty of money it's not like you can get a new one via Amazon Prime.
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Not Amazon, but if your engine is a common model a factory overhaul exchange can get you up quickly. Your ap pulls the engine while the exchange is en route. Crate arrives , new engine on the plane, old engine goes back to factory.

That of course given that you don’t do a firewall forward.
 
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