engine disuse and resale value

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Dave Taylor
I am looking at buying an airplane, and over half of them are 'less than 10 hours in the past 2 years'.
These are IO-550's based in the SE.
"4 hrs in 2016, 5 in 2017, 400 snew in 2006"
"no current annual; has flown 3 hrs this year, 10 last year, 700smoh "

Is the fear of lifter corrosion/spalling and cam damage that real, or is it a "< 10% thing"? Am I wrong to be concerned? How much to discount what a fair price would be otherwise? None? Full overhaul price? A risk-based discount?

Reminder to self: when I get sick or lose medical get a pal to fly plane around a few hours each month.
 
You are going to get the full spectrum in opinions I'm certain.

imo the majority of the value in most used airplanes, especially one more than 20 years old, is the engine. If it's not sound the rest often isn't worth much more than parts.

Understand you are perhaps looking at Lancairs that are somewhat newer than the ancient Pipers, Cessna and Bellancas more common among us, so the airframe and avionics might be new enough to bear a material part of the value. But a suspect engine is still a big discounter.

You are dealing with Continentals. The cam may be less of an issue than in a Lycoming, where it's on top. But I am just not a fan of airplanes that haven't been flown regularly. You are likely to find other issues with those (like prop hub seals, for example). But if you can buy it at a price that allows for a healthy allowance towards engine repairs (half the cost an overhaul), go for it.
 
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Here is what I would do.
drain the oil, flush with 2 gallons of kerosene, change the filter add the new oil. fly for 2 hours. send a sample in see what comes back.
Some of these engines are fine setting. others will rust, the oil sample will show high iron when they do.
 
What Tom said or go "all the way" pulling the lifters to inspect. The good side of what you said is the 700 SMOH. A 700 hr engine is pretty well "varnished" inside making it far less likely to rust than a new engine. OTOH I bought a brand new Lycoming engine that was stored in north Florida for 17 years. Pulled the cylinders and found NO corrosion. It had not been preserved for long storage!
 
I am looking at buying an airplane, and over half of them are 'less than 10 hours in the past 2 years'.
These are IO-550's based in the SE.
"4 hrs in 2016, 5 in 2017, 400 snew in 2006"
"no current annual; has flown 3 hrs this year, 10 last year, 700smoh "

Is the fear of lifter corrosion/spalling and cam damage that real, or is it a "< 10% thing"? Am I wrong to be concerned? How much to discount what a fair price would be otherwise? None? Full overhaul price? A risk-based discount?

Reminder to self: when I get sick or lose medical get a pal to fly plane around a few hours each month.

My 310 hadn't flown many hours per year in the last 10 years prior to me buying it but was hangared in the Midwest. It did have an annual conducted every year on time. 10 years before I purchased it a well known engine/maintenance shop owned it and they had done a lot of good maintenance on it (i.e. replace aux fuel bladders, zinc chromated the interior flaps/wells behind the engines, etc). I paid a value for the plane considering the lack of hours flown, the new interior, newer avionics and other general conditions. I did have to O/H the props as the seals basically dry rotted (mentioned above) but that combined with the purchase price and a couple other minor maintenance things that showed up kept me at a fair price (in my mind).

The engines had approximately 400/470 hours on them after O/H by a reputable engine shop. I did have a good pre-purchase done by my mechanic who was a prior 310 owner and he gave me a thumbs up. After flying her for ~30 hours I changed the oil, sent off the samples to blackstone and cut the filters with fingers crossed. Not a shred in the filter and blackstone gave me two solid thumbs up on the engines.

In closing, I agree it would feel better purchasing a plane that has low to mid time engines that is flown regularly but you can luck out with one that wasn't. If it's the plane that otherwise fits your mission, everything else looks good and you can get a fair price all things considered, you may end up with a plane that will serve you well for many years to come.

Good luck in your journey.
 
The problem with Tom's and Charlie's Best Practices is, there is not a seller in the world that is going let you flush their oil sump with Kerosine or pull a jug. In their mind,
a) there is not a thing wrong with their baby;
b) they'll just wait til a sucker comes along.

I'm starting to think it would be best to buy a runout which everyone agrees is long in the tooth and due a discount, then oh or replace it.
 
The truth is the planes will be priced just like any other with a mid time engine regardless of frequency of use. In the sellers mind if it starts, runs, and doesn't burn excessive oil during the test flight that it is good to go. You may get lucky like I did or you will have nothing but a core on your hands. My bigger concern would be the avionics, those sensitive electrical components do not like to sit.
 
It's a crap shoot....

If I were doing the inspection....I'd want pictures of each cylinder wall, valve seats and valve faces. If they looked good I might take a chance....but it would be priced accordingly. Mine sat for two years and I've had no surprises....but it came from the North West....not the corrosion ridden South East.

I'd anticipate leaky valves from pitting......not cam issues (TCM is a whole nuther can of worms than Lyc)
 
Buying a mid-time engine that's flown lightly in the past couple of years wouldn't bother me at all. I've only known a couple of guys who've had big Continental cams fail in recent years and those were flown a lot. Statistics don't support the fear of the cam in Continentals. On the other hand, I've bought two Continental factory remans that never saw 100 hours before they failed. Myself? I'd prefer the mid-time to a reman!
 
I am looking at buying an airplane, and over half of them are 'less than 10 hours in the past 2 years'.
These are IO-550's based in the SE.
"4 hrs in 2016, 5 in 2017, 400 snew in 2006"
"no current annual; has flown 3 hrs this year, 10 last year, 700smoh "

Is the fear of lifter corrosion/spalling and cam damage that real, or is it a "< 10% thing"? Am I wrong to be concerned? How much to discount what a fair price would be otherwise? None? Full overhaul price? A risk-based discount?

Reminder to self: when I get sick or lose medical get a pal to fly plane around a few hours each month.


Let’sgo:
I’ve always been a proponent of using the same mechanic/shop that will maintain your new aircraft for all your pre-buy research/work. Sit down with him/them and go over your current options and potential issues with your prospective aircraft. Once a potential airframe(s) is collectively selected, put a value on their conclusions and negotiate a potential offer with seller.

If acceptable pack up your mechanic and check the plane(s) out. You both can work out potential future issues and how to take care of those issues at the next annual/inspection with the aircraft right in front you.

While nothing is guaranteed in aviation, I’ve found the above method to help foster a good relation with your mechanic and also give you a good foundation on possible future costs.
 
The problem with Tom's and Charlie's Best Practices is, there is not a seller in the world that is going let you flush their oil sump with Kerosine or pull a jug. In their mind,
a) there is not a thing wrong with their baby;
b) they'll just wait til a sucker comes along.

I let my buyer do the pre-buy at FletchAir (which is known to hunt for stuff). My pre-buy agreement said I'd pay for "airworthy items", FletchAir's list was mainly near future type things and some really not necessary, but I understand it is their job to give the buyer a huge list for "negotiating purposes". I allowed them (at buyer's expense) to do the SB188 wobble test and a few other things not usually performed at annual.

I fix things often before they occur, so a lot of the items listed were things not related to airworthy or safety. I also had one item listed that I called them on after consulting with Mike Busch, and they agreed it was a B.S. mistake. Price paid was pretty much at the purchase price. Didn't hurt that I had 5 other buyers that sent pre-buy agreements in after the first one that were calling daily.
 
The problem with Tom's and Charlie's Best Practices is, there is not a seller in the world that is going let you flush their oil sump with Kerosine or pull a jug. In their mind,
a) there is not a thing wrong with their baby;
b) they'll just wait til a sucker comes along.

I'm starting to think it would be best to buy a runout which everyone agrees is long in the tooth and due a discount, then oh or replace it.

Or c) they are afraid of invasive prebuys by unknown mechanics.
 
Funny, I was thinking just today that if someone had the cash to buy a seldom used plane at a discount and fly the crap out of it for a year, repair whatever issues cropped up, and sold it after getting it "frequently flown", whether they could make some money after having fun with it (assuming the engine didn't crap out).

Wow, that was a long sentence.
 
Funny, I was thinking just today that if someone had the cash to buy a seldom used plane at a discount and fly the crap out of it for a year, repair whatever issues cropped up, and sold it after getting it "frequently flown", whether they could make some money after having fun with it (assuming the engine didn't crap out).

Wow, that was a long sentence.
This is doable with the right aircraft.
But remember you make your money buying, not selling because the market will only support a certain price.
 
What Tom said or go "all the way" pulling the lifters to inspect. The good side of what you said is the 700 SMOH. A 700 hr engine is pretty well "varnished" inside making it far less likely to rust than a new engine. OTOH I bought a brand new Lycoming engine that was stored in north Florida for 17 years. Pulled the cylinders and found NO corrosion. It had not been preserved for long storage!
Simply shows EVERY engine is a Pandora's box.
 
The problem with Tom's and Charlie's Best Practices is, there is not a seller in the world that is going let you flush their oil sump with Kerosine or pull a jug.
That's not entirely true, when the seller wants it gone bad enough,
 
Therein lies the rub. Guess wrong and you are way upside down.
Not to say your idea has not happened.
Many ramp queens are not worth a rebuild engine, but some are, choose wisely :)
 
That's not entirely true, when the seller wants it gone bad enough,

"I want this airplane so gone, I will let a stranger fill my sump with JetA"

I'm thinking this is going to be an exceedingly rare occurence.
 
imo the majority of the value in most used airplanes, especially one more than 20 years old, is the engine. If it's not sound the rest often isn't worth much more than parts..

More than once I've seen aircraft scrapped out for more than they will sell for whole.
 
Or just price it as a runout, if it turns out engine is fine, then you’re lucky, if not no big deal and you will have the engine overhauled.

You forget, we never get out of a engine rebuild what we put into it.
 
Do a proper prebuy, bores scope, filter cut, test flight off the POH numbers watching and noting temps and pressure, compression test, etc

I've seen engines that sat that were just fine

Seen regular flown engines that were crapped out

And vise versa
 
That's not entirely true, when the seller wants it gone bad enough,
I have a friend who recently purchased a late model twin, which had been dormant at times (West Coast). Seller agreed to let him pull some cylinders. Both engines were condemned (corrosion) and he did negotiate a new price. It was an estate sale, where the sellers were the heirs, so maybe less emotion?
 
I have a friend who recently purchased a late model twin, which had been dormant at times (West Coast). Seller agreed to let him pull some cylinders. Both engines were condemned (corrosion) and he did negotiate a new price. It was an estate sale, where the sellers were the heirs, so maybe less emotion?
Brien23 and I are the two working IAs on the island, we have both told buyers not to buy that POS, but when the priced was reduced they bought it anyway.
 
Brien23 and I are the two working IAs on the island, we have both told buyers not to buy that POS, but when the priced was reduced they bought it anyway.
In this case, he did alright. It was a late model, so the engines weren’t the whole value and he bought it as a dual runout. He has a pretty good track record at buying planes at the right price. The sellers realized the issue and weren’t trying to pass the problem on to someone else. I have certainly seen sellers that were trying to pass the buck, but this isn’t one of those cases. I was just trying to back up your point that some sellers will allow this.
 
Plenty of good advice above.

Additionally the wise thing to do would be to budget for the worst case scenario. If you can afford to replace the engine, you can afford to roll the dice at whatever level you feel comfortable with.

And of course it’s a single, so you’re rolling the dice a little harder perhaps than a multi with your butt, but not as much with your wallet.
 
If its in the dry air of the west, it might be ok. Change the oil, put 20 hours on it and do a compression test and filter check and you will know.
 
If its in the dry air of the west, it might be ok. Change the oil, put 20 hours on it and do a compression test and filter check and you will know.
This is one of the biggest fallacies of the aircraft buying.
dry area aircraft get a coating of dust in their interior, then get moved to wet area and that dust gets wet..guess what happens then?
 
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