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Buy-NoBuy - Mooney M20C Engine Corrosion? Engine: Lycoming O-360-AD1, Firewall Forward


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52 minutes ago, Fred_2O said:

Curious question that might help in this situation.  Is it possible to buy parametric insurance on a/c engines?   For example, buy a policy for $X,000 that if it needs an overhaul in the next 200 h or two years due to corrosion as determined by the rebuild shop, then the policyholder is paid $25k?   I wonder what the premium would be on something like that?  

Looking for something like this ?

https://www.beechtalk.com/forums/viewtopic.php?f=43&t=158187

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I saw that. An IO470 is 13k a year. Easy math. But half a new engine every year. And when yours goes bad you pay the cost of diagnosis, and we decide the scope of repair. 

Edited by jetdriven
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17 hours ago, James0519 said:

Also the planes engine (cylinders, Cams) has not been opened up since 2003. (oil has been changed expect those low time years) (maybe the owner changed it) 

 

4 hours ago, mooniac15u said:

I keep hearing people suggesting pulling a cylinder to inspect the cam during a PPI.  Has anyone actually encounter a seller who would allow the buyer's mechanic to remove a cylinder during a PPI?

You can't view the camshaft and lifters in a IO-360 with standard lifters without opening he crankcase.  I've heard two answers as to whether you can do so when the Lycoming has roller tappets, but I'm guessing that does not apply here.

 

16 hours ago, Stephen Watkins said:

Definitely insist on a borescope inspection of all 4 cylinders as part of the pre-buy.    You will be able to confirm or eliminate the question on corrosion in the cylinders...and get a look at the heat pattern on the exhaust valves..

This.  You might find information that suggests the overall health of the engine, and it is considered non-invasive (you only need to remove a spark plug)

IMO, there is certainly some risk with sitting 2-3 years at a time, but that in itself is probably not a gamestopper.  Some of that risk might be mitigated if you find out the engine was pickled for some or all of that time.  If the seller has oil analysis trends available, that might be helpful, but I'm guessing it's gone through multiple owners, so that might be challenging.

The whole debate about whether to do a pre-buy inspection (and the subsequent flame wars) is easily available to read here on MS.  Suffice it to say, most places I've seen charge a flat fee for a complex PPI (maybe a little less than 1 AMU), so the potential purchase price (and the potential repair costs) would be a factor in deciding to do it.  If the selling price is $20-30k, I might forego the PPI.

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 Visual of the camshaft and lifters or price it as completely run out. Your choice but a $25,000 engine makes this airplane not that great of a deal right ?

fwiw we did this and it was clean.  Yet still 250 hours later we had to stick a 33,000$ engine on the plane. Temper your decisions with our experience 

Edited by jetdriven
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44 minutes ago, jaylw314 said:

If the seller has oil analysis trends available, that might be helpful, but I'm guessing it's gone through multiple owners, so that might be challenging.

The nice thing I have found is AVLAB did the oil analysis on my engine for some of the previous owners, and once I started sending in my sample for analysis, I could see everything going back as far as they had it. The engine was installed in 2003, I bought the plane in 2013, and the oil analysis records go back to 2005. I have been able to see what the engine has been doing over the long run rather than just when I have owned it. While there are some years with owners who did not do analysis (at least not with AVLAB), it is reassuring to watch how the figures change over time.

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For my comfort level... or to be in this game... YMMV... Airplane ownership, not for the faint of heart or light of wallet.

  • 1 AMU - waking around money (hip pocket)
  • 10% of purchase price for first annual (checking)
  • 10 AMU - emergency maintenance fund (savings)
  • Be able to access the cost of an engine anytime from day 1 forward. (Credit card, home equity, Uncle Vinny, etc)
  • And in the worst case, walk away from the entire thing without suffering financial ruin. (discovery of a corroded spar, as an example)
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I'm gonna play devil's advocate and say that since the thing you're most worried about is a spalled camshaft and maybe some rusty cylinders, not a full overhaul, I'd price it accordingly.  A tear down, new camshaft and lifters, and 2 overhauled cylinders will run you about $10,000, and may not even be necessary.  

If you really love the airplane, I could see splitting that cost with the current owner and take $5,000 off the price.  If you get lucky, you save $5k.

But like everyone else has said, you're still buying an airplane with minimal avionics and no autopilot- you're better off paying more now and save money later.

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31 minutes ago, gsxrpilot said:

For my comfort level... or to be in this game... YMMV... Airplane ownership, not for the faint of heart or light of wallet.

  • 1 AMU - waking around money (hip pocket)
  • 10% of purchase price for first annual (checking)
  • 10 AMU - emergency maintenance fund (savings)
  • Be able to access the cost of an engine anytime from day 1 forward. (Credit card, home equity, Uncle Vinny, etc)
  • And in the worst case, walk away from the entire thing without suffering financial ruin. (discovery of a corroded spar, as an example)

I think we have finally arrived at the same spot.   I would probably include bullet 2 with bullet 3 if it were a vintage Mooney.   For a newer plane you are probably spot on.  

Might want to include the

  • Prebuy /flying around the country looking at planes 3 AMU
  • Getting her home $2 AMU
Edited by Yetti
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1 hour ago, jaylw314 said:

 

You can't view the camshaft and lifters in a IO-360 with standard lifters without opening he crankcase.  I've heard two answers as to whether you can do so when the Lycoming has roller tappets, but I'm guessing that does not apply here.

 

 

If you pull the rocker arms, push rods and tappets is the cam not right there?

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15 minutes ago, Yetti said:

If you pull the rocker arms, push rods and tappets is the cam not right there?

No, Lycomings use mushroom-shaped tappets with the mushroom inside the crankcase.  They can only be removed from the inside as a result.  The aforementioned roller tappets I'm not sure on, I think @M20Doc said they cannot be removed from outside, but Mike Busch suggested they could be.  That was an off-the-cuff answer during a webinar, so I suspect M20Doc is correct.

Continentals use a barrel-shaped tappet that can be pulled out from the outside.

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8 hours ago, James0519 said:

@SantosDumont so would you say for 45k, that engine time per year, and avionics I could find a better one in a year maybe that would have a Garmin 430+,stec etc?

Also everyone, what are your thoughts on clubs? 

@gsxrpilot is right that spending money upfront for already installed components saves you in the end.  The guy that did all the upgrades to my F spent over $100k to basically turn it into a J.  I paid significantly less than that.  Any upgrades you put into the plan are going to be worth pennies on the dollar later.

Clubs or Partnerships?  Clubs are good if you don't need the exclusivity and availability of owning your own airplane.  If you're just going to get a $100 hamburger every once in a while then club is a great option.  If you're actually gonna go somewhere for a week, club probably won't work.

Partnerships are like marriages.  With the right partner it can be wonderful, with the wrong one absolute misery.  You need to be on the same page for maintenance, upgrades, availability, etc.

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9 hours ago, mooniac15u said:

I keep hearing people suggesting pulling a cylinder to inspect the cam during a PPI.  Has anyone actually encounter a seller who would allow the buyer's mechanic to remove a cylinder during a PPI?

Yes quite often.  I’ve pulled cylinders after they were found corroded on a PPI only to discover that the cam had pitting as well.  The deal still moves ahead with different numbers which are agreed to before cylinders are removed.

Clarence 

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@Yetti 20 hours? Is this true if you pull cylinders to just inspect them  or open the crank case to inspect the camshaft etc?

@SantosDumont yeah I am very hesitate on clubs. Due to the partnership situation.

@M20Doc yeah Doc, I am also wondering, even if metal isn't in the oil filter yet, can their still be corrosion happening?

Main thing I am having with this plane is its far away like a 10 hr flight home and I might be taking everyone's advise which is buy a plane with upgraded avionics when I can find one with mid engine time. Also closer to home.

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1 hour ago, SantosDumont said:

@gsxrpilot

Partnerships are like marriages.  With the right partner it can be wonderful, with the wrong one absolute misery.  You need to be on the same page for maintenance, upgrades, availability, etc.

I read that as "Partnerships are like margaritas"

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I think that we have identified that there was some bad metallurgy of cams from mid 1990s to early 2000s.    Engines are a crapshoot.  There are no guarantees.  Even on a new engine.   It is 5 hours to break in new cylinders.  20 may be a bit high, but I would be taking the cowl off and watching it close.

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58 minutes ago, James0519 said:

@Yetti 20 hours? Is this true if you pull cylinders to just inspect them  or open the crank case to inspect the camshaft etc?

@SantosDumont yeah I am very hesitate on clubs. Due to the partnership situation.

@M20Doc yeah Doc, I am also wondering, even if metal isn't in the oil filter yet, can their still be corrosion happening?

Main thing I am having with this plane is its far away like a 10 hr flight home and I might be taking everyone's advise which is buy a plane with upgraded avionics when I can find one with mid engine time. Also closer to home.

There is seemingly little to explain these engines.  Some that you think should corroded last forever with no issues.  Others are very new have had cam issues.  In my opinion the only way to know with certainty is and internal examination which requires removal of either the left or right set of cylinders.

You may be further ahead finding something with more upgrades completed, than buying what may amount to a project.

Clarence

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14 hours ago, M20Doc said:

Yes quite often.  I’ve pulled cylinders after they were found corroded on a PPI only to discover that the cam had pitting as well.  The deal still moves ahead with different numbers which are agreed to before cylinders are removed.

Clarence 

So, that was after you already found corrosion in a cylinder?  Have you removed a cylinder on a PPI of an otherwise healthy looking engine to check the cam?

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Do we know how the spar looks on this plane?  Engines are fixable.   Spars are fixable, but usually turn the plane into a parts airframe.   Of course the sum of the parts can be more than the whole.

Edited by Yetti
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21 hours ago, KLRDMD said:

Without reading the fine print, it seems similar to my example.   That would provide an option for this case if the fine print is acceptable to the buyer of an a/c that has not been flown frequently.   Perhaps you could negotiate a lower purchase price that would allow you to buy such a policy.  It does give an indication of how much financial risk is for just any-old engine before overhaul.

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3 hours ago, mooniac15u said:

So, that was after you already found corrosion in a cylinder?  Have you removed a cylinder on a PPI of an otherwise healthy looking engine to check the cam?

On very few occasions where the buyer and seller agreed based on many years of sitting.  Another check if the engine has been sitting is to pull the magnets to look at the gear train.  Slick magneto impulse couplings corrode quickly.

Clarence

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We pulled a cylinder off the 1300hr IO360 as part of our prebuy way back in 2010. Just when this spalled cam discussion was just getting started.  It was a 2001 field overhaul with a new Lycoming cam and reground Aircraft Specialties lifters. The engine had 100hr per year in Tulsa and 50 hours in 2008.  15 in 2009.. They looked good. after 250 hours we had 3 spalled lifters and two eaten up cam lobes.  33,500$ later we were flying again. It sure turns a 60,000$ airplane into a 100,000$ one pretty quick.

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On 10/3/2018 at 7:42 PM, Antares said:

You should always go into buying an airplane with the plan/ability to replace the engine unless it’s still under warranty. With that said, that one looks like a candidate to start making metal and unless it’s priced accordingly, I’d keep looking. An 800 hour engine at 50 hours a year for 16 years is still a risk, but I’d still consider it an 800 hour engine. I bought my first Mooney with 1100 hours and 17 years on the engine and got another 1000 out of it over the next five before it ate the camshaft, but it was consistently flown 50-100 hours/yr. 

Umm...any engine is a risk, including a fresh overhaul.  How many hours a year do you think is the magic number is to keep the valve train from spalling?   My IO360A1A was 33yrs old and had 1800TT with years of inactivity when we overhauled it. No cam spalling and all compressions over 74.  We overhauled a few years after it swallowed a valve in cruise.    Does that matter? NO...it's just as anecdotal as any other story on this board. 

If everything else about this plane is desirable, negotiate a price discounted for inactivity and then ask to pull a cylinder at buyers expense before the sale.   There are boatloads of Lycomings that survive long periods of inactivity just fine (My hanger neighbor's Comanche 250 unflown for 5 years running strong for the last 2).  The thing is, no one bitches about a previously inactive engine that goes back into service for the remainder of TBO.

They're all a gamble. To what degree depends, but the risk an be mitigated. No one here can say how well or how long that O360 will remain in service.

 
 
 
 
 
 
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