Replacing the engine

[mrjones30]

On average what would be around the amount of hours on an engine that you would be looking at a replacement? The reason why I asked is because there are some pre owned Mooney's that are attractive but have a lot of flying hours. (1,500 Hours).

 

Thank you

[mrjones30]

[Jeff_S]

Engine replacement, or overhaul, will depend on many factors. Some subscribe to the theory that you should do so at, or near, the manufacturer's TBO time because, well, that's what they recommend. But there is a growing school of thought (to which I subscribe) that mere engine time is not a great indicator of whether or not it's time for major work. There are many diagnostics you can do now to check the condition of the parts, including borescoping the cylinders, oil analysis, and regular use of an engine monitor during flight. All these, if used correctly, will give you an indication of whether or not your engine is in need of major work.

It's called condition-based maintenance (I think...may have gotten my term wrong) but if you search around here and the Internet you'll find out a lot. In particular, go to Mike Busch's website (http://www.savvymx.com) to the Resources Area and recorded webinars, and there's a whole webinar that discusses this exact thing.

 

[carusoam]

One man's experience...

Most Mooneys have a 2,000 hr TBO. ( recommended time between overhauls).

On 1500 hours, you are expecting an overhaul in about five years time, if you fly 100 hours per year.  The older the engine is, and the more hours it has, the more risk you have of it needing work done on it, possibly sooner.

Really old alternators, starters,  carburetors, tires, and unexpected maintenance items can beat up your bank account.

This plane is 3/4s the way to the expected overhaul expense.

Adjust your purchase price properly.  There will not be much time to save up for the overhaul if you are spending your money paying off a 15 year note.

If you have dough in the bank already, this is not high risk gambling.  You will need the overhaul sooner than you want to pay for it.

Weigh your odds, make your choices, don't skip a good pre-buy inspection.

A well kept Mooney is a great plane to own.

Best regards,

-a-

[rbridges]

I'm new to flying, but I've read a lot of posts here.  It seems that it ranges quite a bit, just like a car.  it depends on maintenance, how often it's run, and IMO a little bit of luck.  I've heard guys bragging about going 2500+.

[carusoam]

Rob,

I expect TBO from my plane and will take what it gives me after that.

My last two GMs have given me better than ten years, and 150k miles with standard maintenance.

Keep in mind 2,000hrs X 150mph = 300k miles

You get a lot from a Mooney's engine.  Treat it and maintain it well.

I might expect 2500 is posible from gentle, weekly operation, but would avoid depending on it during my "can-I-afford-it" calculations.

-a-

 

[rbridges]

I agree.  I definitely wouldn't count on it in my budget.  I bought my plane with 780 SMOH, but it was only 150 STOH.  I'm sure the top overhaul wasn't cheap and could have grounded the plane if the previous owner was stretched thin.

[carusoam]

My  M20C got a cylinder exchanged after my first few hours of flying it.  The plane previously sat outside for two + years without running.  The result was a stuck valve and a few bucks to fix it....

Great plane. served me well. Lasted a decade. I was younger then.....and the Internet did not exist at the time.

-a-

 

[N601RX]

Very few engines make it to TBO without some cylinder work or a fresh top end.  Judging from the logbooks I looked through when we purchased this seemed to be a pretty common occurance at around 1100-1200 hrs.

[carusoam]

Mike,

Just to clear my point.....

I wrote of my experience. Top OH would be worth calculating in, but I did not experience the need to have one on my M20C.

I am at 12 years of flying, two Mooneys, and required only one cylinder.  Sitting outside without running for years is definitely a bad idea.

I think you might see turbo engines are more likely to get new cylinders.

Sounds like a good idea for a poll?

-a-

[John Pleisse]

For big bore Continentals, you should pad in $15,000 for a top overhaul, prop, FI servo-lines-nozzles and new mag and harness. If you end up not needing it....bonus. The I0360 Lyc's and Continentals can go to tbo, but you should watch them carefully, especially above 1500 hrs.

This brings up another point. You can throw a lot of good money after bad as an engine approaches tbo. You should figure out a dollar value commitment before you throw in the towel and just OH it. Remember, many airplanes are for sale for a reason. 

[RJBrown]

Quote: N601RX

Very few engines make it to TBO without some cylinder work or a fresh top end.  Judging from the logbooks I looked through when we purchased this seemed to be a pretty common occurance at around 1100-1200 hrs.

[DaV8or]

When it comes to buying an airplane, TBO is a hard, fixed number. You deduct from the value of the plane for every hour closer to TBO. Example- an M20J with zero time motor is valued at $100,000. The same airplane with your 1500 hour engine would be valued at $81,250 and you should make your offer like this (or lower). It is based on a $25,000 cost to OH the engine in the J, so 1500 hours is 75% of the engine's life used up, so .75 x 25,000 = $18,750 deduction. Logbooks, owner's flight history, oil annalysis, borescope, compression check and filter check are all nice to knows and may help sway your decision, but in making an offer, TBO is a hard number and most sellers understand this.

When it comes to owning an airplane, TBO is a suggestion unless you intend to use your plane for commercial purposes. Operation on condition is a common practice and only you, the owner can really say when it's time. Some will do it at the first sign of trouble and pull the trigger before TBO, others right at TBO no matter what and others will fly it till it quits. I think a real common strategy is to go to TBO, get a few "free" years in, then do it.