20 Year old engine with 150 hours

[Fusco]

I recently bought a 65' M20C and I need my 10 hours of instruction for insurance purposes. I hired a mooney instructor to get these hours and he saw in the logbook that the engine was overhauled in 2001 but now only has 150 ish hours. The majority hours are in the last three years and the plane sat for a lot of time before hand. The instructor said he won't fly it until it gets bore scoped. The plane also has a very minor fuel leak which will be fixed soon but I was hoping to get my 10 hours beforehand so I won't have to deal with instructors. I am wondering how the people on here would feel about the engine and if they feel that it is really an issue or that the guy is being overly cautious. He currently flies an Ovation with a glass panel so I'm wondering if maybe he's just use to much more expensive airplanes. I'm new to airplane ownership and Mooneys so I just wanted some extra opinions, thank you! 

Edited January 7, 2023 by Fusco

[RLCarter]

Bore scoping the cylinders will not show bad cam/lifters. Lycoming has a recommended time for calendar month and/or hours, you’re well below hours but beyond the months. If it’s been flown regularly for the past 3 years and it’s not making metal or leaking oil from everywhere I wouldn’t be too afraid to fly behind it. Get an A&P to run the compressions and bore scope it (couple hours labor) to make your CFI happy and go fly it…… congrats on your new bird and welcome to MooneySpace

[Fusco]

8 minutes ago, RLCarter said:

Bore scoping the cylinders will not show bad cam/lifters. Lycoming has a recommended time for calendar month and/or hours, you’re well below hours but beyond the months. If it’s been flown regularly for the past 3 years and it’s not making metal or leaking oil from everywhere I wouldn’t be too afraid to fly behind it. Get an A&P to run the compressions and bore scope it (couple hours labor) to make your CFI happy and go fly it…… congrats on your new bird and welcome to MooneySpace

Thanks for the reply! They ran the compressions and they look solid. 

[Robert Hicks]

Find a new CFI.

[DonMuncy]

What you are describing is an engine with potential problems, but none likely to cause a castastropic failure, or full loss of power. I would not be afraid to fly it, but I would hesitate to get a couple of thousand of miles away from home before I had some experience with the engine. (Oil consumption, metal in the filter, etc.)

[A64Pilot]

5 minutes ago, Robert Hicks said:

Find a new CFI.

Really, because the worst case is you lose a cam / lifters and while that’s catastrophic financially, I’ve never heard of it causing a crash.

Next worst thing is rusted bores which will show up in lowered compression and high oil consumption, another wallet hit but not a safety concern.

Depending on your finances you may consider purchasing a borescope, they aren’t that much, easy to operate and may well help catch issues before they get expensive.

Just a nice tool to have if your the type that plans on doing their own preventive maintenance.

Or not your choice of course, but your Instructor is showing his ignorance because a borescope isn’t going to discover any real safety issues, that’s more likely to be found in an oil filter inspection.

Get your hours, I’d concentrate on landings and aircraft control during takeoff and after landing because it seems most accidents happen there. People often say don’t do touch and goes for some reason, but I think you should and become comfortable with go-arounds without re-configuring anything, if you have to reset trim and flaps etc you could probably just stop in the same time. But get real comfortable with landings, most I think come in too hot, learn to land slower and on the mains, if the nose wheel touches down at the same time as the mains your setting down too fast in my opinion.

Once you become comfortable landing on the mains and carrying the nose in the air, I think you’ll enjoy your airplane more.

As a side note if it hasn’t flown much in a long time I think I’d do my first oil change way early, if there was any rust etc even just a little best I think to not leave it there, fly it for at least it’s first ten hours as if you were breaking in new cylinders, and I think pattern work with all the full power takeoffs is a good way to do that.

[Guest]

I’d be more concerned with dated magnetos, carburetor and fuel pump.  Either of these can stop your flying before a corroded cylinder or camshaft.

[DXB]

16 hours ago, M20Doc said:

I’d be more concerned with dated magnetos, carburetor and fuel pump.  Either of these can stop your flying before a corroded cylinder or camshaft.

Certainly mags are delicate. I’m curious what issues you see with carbs and engine driven fuel pumps from sitting and do they apply to regularly flown parts of the same age (e.g. my 1600hr O-360-A1D last overhauled in 2000).  

An engine sitting for 20 years is a bit unsettling but successful use for 150hrs in the last 3 does provide some reassurance?

Agree CFI is being silly in thinking a “borescope” will make any difference, but is he right to be concerned overall?

[Fly Boomer]

37 minutes ago, DXB said:

Certainly mags are delicate. I’m curious what issues you see with carbs and engine driven fuel pumps from sitting and do they apply to regularly flown parts of the same age (e.g. my 1600hr O-360-A1D last overhauled in 2000).  

An engine sitting for 20 years is a bit unsettling but successful use for 150hrs in the last 3 does provide some reassurance?

Agree CFI is being silly in thinking a “borescope” will make any difference, but is he right to be concerned overall?

Don't know anything about the CFI but, as I get older, there are more and more people and airplanes I won't fly with or in.

[Mac80]

My experience with cam lobes wearing down excessively I believe was at overhaul before I purchased the plane they did not replace the cam followers at least not recorded. 

The engine gradually made less power at about 600 - 700 hours that was more noticeable when firing on one set plugs under power in air. There was some very slight metal in filter but hardly noticeable.

I realize the plane is new to you but if it makes good power the cam is probably OK.

 

[DCarlton]

Nothing wrong with a little advice, but the issue seems to be that the CFI is dictating maintenance requirements instead of your mechanic.  

[UteM20F]

We were looking at a Mooney with a 20+ year old overhaul with a similar number of hours, but not recent hours.  I emailed Mike Busch to get his opinion, and he responded that he would ask the seller if we could escrow the amount of an overhaul, and if the engine made metal in the first 100 hours (in the first year), have the seller pay for it.  The thinking is that if the engine does well for 100 hours of recent use, it likely doesn't have corroded lobes.

We went with a different Mooney.  Today is the 1 year anniversary of buying it.

The fact that your engine has lots of recent hours would make me comfortable with the engine.

Ute

[Guest]

6 hours ago, UteM20F said:

We were looking at a Mooney with a 20+ year old overhaul with a similar number of hours, but not recent hours.  I emailed Mike Busch to get his opinion, and he responded that he would ask the seller if we could escrow the amount of an overhaul, and if the engine made metal in the first 100 hours (in the first year), have the seller pay for it.  The thinking is that if the engine does well for 100 hours of recent use, it likely doesn't have corroded lobes.

We went with a different Mooney.  Today is the 1 year anniversary of buying it.

The fact that your engine has lots of recent hours would make me comfortable with the engine.

Ute

I think Mike is dreaming!  I’d love to see him negotiate keeping $30-50K in escrow while you fly around for a year testing the engine.  If the concerns are so great, pull a cylinder for an internal inspection.

[UteM20F]

34 minutes ago, M20Doc said:

I think Mike is dreaming!  I’d love to see him negotiate keeping $30-50K in escrow while you fly around for a year testing the engine.  If the concerns are so great, pull a cylinder for an internal inspection.

I don't disagree with your sentiment.  We thought how we would word a sales contract, and everything that we came up with would have been rejected by the seller, as we would have rejected such a contract if we were the sellers.  Although we liked the plane, we passed on it as we weren't willing to offend the seller with such a contract.

The reason for my original post was to show my (and I think Mike's) support for the engine being good with so many recent hours, in spite of an old overhaul.

Ute

[kortopates]

I did transition training for someone that had bought an F model with similar pedigree and no pre-purchase inspection. He was active duty trying to save some $ and thought he found a good deal. On our first climb out i couldn’t believe the anemic climb performance from essentially a sea level airport. Although we completed the training, I also reviewed the POH performance tables with him and showed him we literally only got 1/3 of the POH climb rate for our weight. I suggested he measure the amount of valve lift on each cylinder when warm, comparing the amount of lift on each. it’s usually a shared intake cam that wears down first. Sure enough that’s exactly what he found. so i referred him to a mechanic that would next bleed down the lifters to get accurately verify what the owner roughly measured. I really felt bad for the new young owner. Personally, I think it’s a huge mistake for a fist time buyer to skip the pre-purchase inspection and test flight and go straight to negotiating. Plus it’s got to be very rare when a new owner doesn’t at least make up the cost of a pre-purchase inspection with items found and corrected at the seller’s expense. Of course a PPI isn’t a panacea for finding everything. It’s intent is to find big ticket items and even there is not always entirely successful. But skipping it is nuts to me.


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[kortopates]

I don't disagree with your sentiment.  We thought how we would word a sales contract, and everything that we came up with would have been rejected by the seller, as we would have rejected such a contract if we were the sellers.  Although we liked the plane, we passed on it as we weren't willing to offend the seller with such a contract.
The reason for my original post was to show my (and I think Mike's) support for the engine being good with so many recent hours, in spite of an old overhaul.
Ute

It still takes on average a year to a year and half for an engine that has been sitting for a period of time to start making metal after being flown extensively again. It takes time for the engine to prove it self.


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[carusoam]

Cooool….

I once bought an M20C that sat in NJ for a couple of years, outside… it was built a couple of months after yours/the OP’s…

It got a small budget PPI to match the small budget airplane…

It got the small budget Transition Training as well…. With a really low hour CFI…

There was no engine monitor in the small budget program…

And… I had no other aviators in my family…

Result…

A Valve stuck within the 10hr transition window… on departure from a Delaware airport… bending the valve stem when the valve face left a dent in the piston crown…

All of this ended successfully, by returning to the intersecting runway…. Yay!  (Great young buck CFI, he did remarkably well…)

 

Get ready to learn about your machine…

If you have an engine monitor… learn how to use it…

Get it’s data, send it to Savvy… read its graphs on your PC…

There is a ton of info you can see for yourself… No CFI required.

Get to know your mechanic because you can….

 

There is a small percent chance a cam lobe can get ground down… by its pock marked cam follower….

Lobes and followers can be inspected, valve guides can be reamed…

Engine performance can be measured… T/O distance and climb rates tell a ton about engine health as Paul mentioned above…

Bust out the POH… get your WnB app going… check the OAT… calculate the expected performance…. Compare against the actual…

Use a WAAS source combined with CloudAhoy app on your iPad if you have the coin…

If everything works out… you will be flying an Ovation in about 10years….

Statistically n=1 for people that have prior experience buying an M20C that sat in NJ in this conversation…. YMMV.   

 

You have been approved to….    Go collect data!

Chances are things are going well… your engine won’t self destruct… but you still have to be ready…

Everybody gets to train like they will experience an engine out in their flying career… engine outs are more likely with aged equipment… and equipment that has sat unused for long periods of time…

other things to check on…

• Got a decent CO detector?
• Does your plane have shoulder belts?

MS has a few good mechanics and CFIs in the NJ area… where is your M20C kept?

PP thoughts only, not a CFI or mechanic… or statistician… or safety guy…

Best regards,

-a-

[DXB]

16 hours ago, M20Doc said:

I think Mike is dreaming!  I’d love to see him negotiate keeping $30-50K in escrow while you fly around for a year testing the engine.  If the concerns are so great, pull a cylinder for an internal inspection.

You're absolutely right about Mike Busch's idea.  Unfortunately I think most sellers would also rightly balk at pulling a cylinder just to look at the bottom end. Plus you may need to pull two for a good look.  Compression checks, borescope exam, and checking the screen and filter at least 10 hours after oil change is probably where most would draw the line. .On another note I think valuation algorithms do a terrible job of incorporating data on how much time an engine has sat unused or how much recent use it's seen while accumulating the hours SMOH.  If there was a valuation standard that included this data, a lot of these arguments at sale would be much easier to head off.

 

[Guest]

6 hours ago, DXB said:

You're absolutely right about Mike Busch's idea.  Unfortunately I think most sellers would also rightly balk at pulling a cylinder just to look at the bottom end. Plus you may need to pull two for a good look.  Compression checks, borescope exam, and checking the screen and filter at least 10 hours after oil change is probably where most would draw the line. .On another note I think valuation algorithms do a terrible job of incorporating data on how much time an engine has sat unused or how much recent use it's seen while accumulating the hours SMOH.  If there was a valuation standard that included this data, a lot of these arguments at sale would be much easier to head off.

 

It would be really hard to come up with a standard valuation for an engine that’s been sitting under used. The variables are too great in my opinion.  

The way for the seller to get higher value than “core value” for his engine is to prove that the engine isn’t corroding away. Pulling a cylinder does that quite well.  Mike’s constant preaching about pulling cylinder has scared many people into believing that cylinders should never come off, ever.

[TheAv8r]

+1, I bought (not my current plane) an M20E that had an engine that was OHed in the mid-90s and only had 500 hours on it. We had the same concern. Compressions were great, what we could see on a borescope was good, but the only way to really answer the question was to pull a cylinder off and take a look at the camshaft. The current owner was an A&P IA and totally understood our thought process, he actually took the cylinder off and put it back on himself and we paid for parts. This let us see everything we needed to, which showed just minor surface corrosion on a few of the lobes, no pitting, no scoring, no lobe wear of any kind. We ran Camguard in it, did 10hr oil changes the first few months, flew the crap out of it and by the 3rd oil change, it was a super clean, strong engine. Never had any issues. If we hadn't pulled off that cylinder, we'd always be in a state of unknown.

[Guest]

3 hours ago, TheAv8r said:

+1, I bought (not my current plane) an M20E that had an engine that was OHed in the mid-90s and only had 500 hours on it. We had the same concern. Compressions were great, what we could see on a borescope was good, but the only way to really answer the question was to pull a cylinder off and take a look at the camshaft. The current owner was an A&P IA and totally understood our thought process, he actually took the cylinder off and put it back on himself and we paid for parts. This let us see everything we needed to, which showed just minor surface corrosion on a few of the lobes, no pitting, no scoring, no lobe wear of any kind. We ran Camguard in it, did 10hr oil changes the first few months, flew the crap out of it and by the 3rd oil change, it was a super clean, strong engine. Never had any issues. If we hadn't pulled off that cylinder, we'd always be in a state of unknown.

Your engine appears to be living proof that cylinders can indeed be removed and reinstalled safely without blowing up.

[Jsno]

if it has been sitting I would suggest pulling a cylinder so that you can get a good view of the Cam and tappets.  If you have a fresh oil change and filter on it before a pretty inspection you may not find any metal indicating cam damage.  A cylinder can be pulled and reinstalled in a day.

[Pinecone]

My airplane got a factory reman in 2019, and flew about 200 hours from then to summer 2022.  

Most of the lifters were pitted.  Luckily on the Contentinenals, you can pull the lifters without putting the cylinders or splitting the case.  Seller paid for a new set of lifters.