Overhaul Age

[MHale]

I've been looking for just the right Mooney for several months now, and I've heard varying opinions on the age of overhaul issue.  Some people say don't consider an aircraft with an overhaul that is more than 15 years old, regardless of hours.  Some people say don't worry about the age at all, and still other people say as long as the engine hasn't sat for any extended period of time, don't worry too much about it, but have a bore scope done during the pre-buy.  I've found a nice C model that has only ~600 since a factory reman, but it was in 1990.  The plane seems to have been flown about ~25 hrs a year, steadily.  What's the opinion of some actual Mooney owners on this topic?

[planebones]

Howdy:  I am an A&P/IA and M20C owner.  I had a M20A (termite hotel) whose engine hadn't bee overhauled since the 70's and never had any trouble right up to 2000hrs. The fuel and oil hoses should be changed  every 8 years or so. The mags are probably due the 500hr mandatory inspection so go ahead and have them overhauled  Spark plug wires deteriorate over time     Older engines may develop leaks requiring simple gasket changes ,(valve cover gaskets, prop seals. ).  The carburetor probably needs the new float installed in it (as per Volare service bulletin,)   so that gets new gaskets at that time. You could change the accelerator pump seal at that time with little added expense.   I do not see age as a large negative factor  (caveat:  I live in Idaho where humidities are low and internal engine corrosion is not a problem.  )   Ken

[Parker_Woodruff]

Be careful, have the funds ready to overhaul...hopefully you'll get lucky.  Mine is about 10 years old but had only flown ~50 hours in the previous 4 years before I bought it.

 

Compressions high 70s and everything looks great..

 

That said I really don't like 25hrs/yr.

[MHale]

Also, the aircraft's been hangared near Tampa.

[airkraft]

I'd be careful. 

My partner had a prop strike two years ago on our 450 hour 1989 factory overhauled engine.  During tear down inspection there was $6,000 worth of internal corrosion related issues that could not have been seen during our borescope pre-buy inspection. The crankcase was aggressively fretted, also.  We decided to overhaul the engine rather than spending $6K to close up a 20+ year old engine while it was already in the shop. 

This is not to imply that the engine might not have made it to TBO, but there's a lot of internal stuff that just doesn't like not being splashed with hot oil as often as possible.

Our aircraft was hangered in Missouri.

[N207LS]

Do you know what airport in Tampa and how long in the hangar there?  I live in St. Petersburg, FL and there are better and worse airports to hanagar a plane, as far as salt air conditions go.  All of the air here is "salty" but there are 4 airports that are literally on Tampa Bay and completely subject to much worse salt conditions than some others in the area.  The four airports with a large GA presence that are directly on the bay are Albert Whitted, St Pete-Clearwater International, Peter O. Knight, and Airport Manatee.  At any of these 4 airports the plane would be subjected to much worse salt conditions than if at one of the others further inland.  Hope this helps.

Aaron

[MHale]

Thanks for the thoughts.  The aircraft is in Brooksville, FL - which I believe is a bit farther inland.

On a related note, what are your thoughts on an engine that has had a prop strike and teardown/inspection vs. overhaul?  There is another aircraft that I'm considering that had an overhaul in 2004, then a prop strike about 100 hrs in, then a teardown/inspection and new prop.

[N207LS]

Brooksville is north of Tampa and not on the water, one of the better spots around here for minimal salt air climate.  Add to that a hangar and much better! 

As far as a prop strike inspection goes, it is just that an inspection.  You will most likely get a lot of opinions on this one, but I am in the camp of buying airplanes with NDH.  I know that planes, like cars, can be repaired properly, but I prefer to buy an airplane that has no damage history.  Check the logs thoroughly to see what other repairs were made at the time of the prop strike.  I would also make sure to find out the cause of the prop strike.  Best of luck.

I would also suggest a thorough pre-buy on any airplane.

Aaron

[N6843N]

In my experience the only way to determine an engines condition is to partially tear it down. I start by pulling a magneto or both and look at the drive gears for signs of corrosion, any seller should be good with that. If there is corrosion I would then insist on pulling a jug from both sides which would give me enough acess to inspect the inside of the case for corrosion damage to the cam and other internal parts. If there not good with that, walk or deduct the price of an O/H. Most engines develop a very good coating of varnish internally which can protect them for VERY long periods of time. I just disassembled a 1960 Chevrolet 283 which was high mileage but has sat for over 10 years on a garage floor less than 200 yards from Lake Huron, with salt coated cars, parked next to it in the winter and it had zero corrosion issues.

[FlyingAggie]

I inquired about a local partnership in a 1964 M20C with a TTAE of only 900 hrs.  The engine has never been overhauled and is running strong with compression in the mid 70's.   Sounds like those engine are well built.

This seems to be turning in to an engine question thread, so I'll post mine.

The 262 I am trying to buy has only operated 1.5 hrs in the last 8 months.  Before that is was flown about 60 hrs/year.  Can an engine signicantly deteriorate in that short of time, so much that it will need major work?  How concerned should I be?  Would a good prebuy detect problems if they borescope the engine?

Finally, are there any special steps you should take the first time you start your engine after it has set for 8 months?

Alan

[Parker_Woodruff]

Quote: FlyingAggie

 Finally, are there any special steps you should take the first time you start your engine after it has set for 8 months?

Alan

[MHale]

That's a perfect segway into my next question - I've all but settled on a nice F model that has ~400 SMOH in 2004, but it hasn't flown much in the last year (~5 hrs).  It's getting an Annual right now, and 3 compr came up >75, while one came up ~55.  The cylinder is going to be replaced by the seller.  Two questions: (1) Should this make me worry (2) What is the best brand/type of cylinder and does it make a difference?

[Parker_Woodruff]

Quote: MHale

That's a perfect segway into my next question - I've all but settled on a nice F model that has ~400 SMOH in 2004, but it hasn't flown much in the last year (~5 hrs).  It's getting an Annual right now, and 3 compr came up >75, while one came up ~55.  The cylinder is going to be replaced by the seller.  Two questions: (1) Should this make me worry (2) What is the best brand/type of cylinder and does it make a difference?

[dlthig]

Do any of you guys ever turn the prop a few times on an engine that has set or is cold before starting?  The idea was to move a little oil around before starting.

[N6843N]

Lycoming service letter L180B deals with most of the questions asked. Lycoming does not recommend turning the prop of an inactive engine. Purely out of curiousity how many of you still have the Lycoming operators manual, and refer to it, that came with your aircraft? The service letter i refered to is titled "Engine preservation for active and stored aircraft". It is a must for Lycoming owners. You Continental guys are on your own. :-)

[dlthig]

I turned the prop on my 180, but that was years ago.  It's funny how some mechanics say to do it, while Lycoming says not to turn it.

[N6843N]

When I went to Lycomings school the instructor explained their theory. He said that by hand turning an engine at some point you will have wiped all the oil from the cam and cylinders which rely on splash and spray for lubrication. This in turn subjects the bare metal to atmospheric conditions which could possibly cause corrosion of the highly polished metal surfaces. If you start the engine, and then go fly it, after turning it by hand I guess that would not be a problem.

[RJBrown]

The question was should you turn the prop just prior to cold or long time inactive start. Not should I periodically turn the prop on an airplane that just sits. I understannd not turning an inactive engine but is it a good or bad idea to turn the prop prior to start?

[GeorgePerry]

I always hand turn my prop through one blade before starting the engine.  I do this for a few of reasons.  (1.) I get to "feel" the internal workings of the engine.  If anything isn't right (Low or no compression, sticking valve etc) I'd feel it in my hands.  (2.) One turn builds compression (albiet a little) before the mags are on, which usually makes for a quicker start.  (3.) I use a EZ tow and like to have the prop completely horizontal and maximize clearence between the tow apparatus and the prop.  To get the prop horizontal I have to pull it through about 45 deg of travel, so It's just as easy to pull it through 3/4 rotation to accoplish reasons 1, 2 and 3.

[danb35]

Quote: MHale

What is the best brand/type of cylinder and does it make a difference?

[GeorgePerry]

Quote: danb35

On an F (Lyc IO-360-A1A), you don't have a choice--Lyc makes the only cylinders out there for this engine.

[danb35]

Quote: GeorgePerry

Not true....ECI cylinders are compatible / approved for the IO-360-A1A

http://www.eci.aero/pages/products_titan_320.aspx

[GeorgePerry]

I have ECI's on my IO-360 A1A.  I can PDF the Yellow tags and the Signature engines overhual if you'd like to see them

[danb35]

Quote: GeorgePerry

I have ECI's on my IO-360 A1A.  I can PDF the Yellow tags and the Signature engines overhual if you'd like to see them

[MHale]

So I guess the next question is - which is better?