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Mooney with TSIO 360 GB


Arthur

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I previously owned a 231 with a GB engine that was intercooled, fixed waste gate.   Unfortunately I had to sell the plane after I had the engine to a level where I was happy with it. I am now looking for another 231. The question is for people who have owned GB engine, not intercooled, but with Gami injectors and the Merlyn waste gate. Did this increase you time towards Major overhaul or was 1400 to 1500 still the number.

Secondly for anyone What percentage of the cost of a major overhaul can be added to the true value of the plane for resale?

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Welcome aboard, Arthur!

So much of a turbo’s cylinder and turbo longevity depends on how it gets operated... is that what you are asking?  Cylinders are at risk from running hot at altitudes. Turbos are at risk when run hot above TIT/1650°F

Many pilots use the plane to go fast, and absorb the cost of all the excess speed as maintenance...

Most people hanging out on MS are interested in minimizing their maintenance costs and learn techniques to do that as well... 

  • intercoolers
  • pressure controllers
  • lots of instrumentation
  • good procedures followed 
  • TIT limits
  • oil changes

We have a company that is in the business of intercoolers around here as well... great support if interested in acquiring one...

There are a few good threads around here that discuss turbo ops and Ks... you might find them interesting... @jlunseth Is one of the interesting authors on the topic, I believe...

 

Plane pricing for an OH and resale never works out in favorable numbers... 

  • Buying a plane run-out is great.  You get to decide who is going to do the OH and break-in...
  • OH the engine and sell the plane...? Many people won’t like your choices... and won’t like infant mortality issues...
  • Mid Time engine is what most planes for sale start being priced with.
  • TC’d planes often expect one top OH near the halfway point.

There is an interesting sale being developed/arranged for a 262...around here... it may only go as a firewall forward project...  find Jimmy from All American’s thread for the details...

Of course, this is NA PP thoughts only, not a mechanic...

Best regards,

-a-

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Thanks for your reply. The basis of my question, is the plane I am looking at has had two major overhauls at  1400 give or take a few. Presently it  is about 300  from that now. If I went in that direction I was curious as to how much if any of an  overhaul could be recouped if it was necessary to sell the plane.  I read an article, TEST Pilot from MAPA which basically said if your looking for a M20K walk past any with the GB engine and of course this plane has a GB engine. I understand it costs money to fly, but I'd rather not waste any along the way.  I didn't notice Gami injectors on your list, have you had any experience with them?

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The problem with the GB is that it runs hotter than the LB, the engine that replaced it.  I don’t think TBO was 1500 on the GB.  My aircraft has the LB and official TBO is 1800. The problem was a combination of the GB running hot to begin with, and then the thinking on how to run the engine was not great.  Cruise power settings with the fuel flow in the 12 point something range were what was recommended, and that puts out plenty of power, but at the expense of cylinder life.  What you may have heard or read, is to expect to do a top overhaul at about 1200.  The GAMI injectors and the Merlyn in my view would not add appreciably to engine life.  The GAMIs just even out the fuel flow between cylinders, if the GAMIs have been balanced properly that difference will be small.  That allows you to run the engine lean of peak, which is easier on it, but I would not bank on the prior owner having done that, most ran it according to the POH, which was hot.  The Merlyn would not add appreciably either.  The Merlyn does a couple of things.  One is that the GB with the fixed (non-Merlyn) wastegate was subject to bootstrapping.  Bootstrapping isn’t so much a problem for the engine as for the pilot who has to manage the throttle. The other thing it did was to allow a higher critical altitude.  The critical altitude with the fixed wastegate was around 15k, in my plane (with Merlyn) I can get to 22k before I run out of throttle.  Critical altitude is the altitude at which a turbo can no longer make 100% HP, so you can climb for a while after that, but the climb rate gets very anemic. All that is nice, but it does nothing about engine temp. The mods that helped with temp are the LB conversion and/or the intercooler.  If the enigne has been run without those, its a decent bet it has been fairly hot, not necessarily, alot would depend on the pilot running the engine, but probably.  My engine had a hard life, I think, before I got it.  I had to do quite a bit of work on it in the first couple of years. But since then, I have run it quite a bit LOP, I am just a little over TBO right now, probably 1801 point something, and the plan is to just keep running it unless a problem shows up.  It is very healthy right now.  I take it you are looking at a plane right now.  If recollection serves, after a certain serial number the engine can be converted to an MB. I can’t do that with mine, but you might look into that and think about buying a plane that could be converted if and when it gets to TBO.  The MB is a better engine than either the GB or LB.

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MAPA is a pretty reputable resource... but...

Know the author?

What made him say something like that...?

If all things we’re priced the same... walking by the lesser versions is easy...

It is really helpful to have the live discussions with explanations like what JL just supplied...

You are now an educated consumer on this topic!

Best regards,

-a-

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I went looking for the tbo on the gb engine.  TCM doesn’t appear to list the tbo anymore, but I found the service bulletin that came out last year lengthening the tbo for engines above a particular SN, and the original tbo was listed at 1800.  I found an article by a third party explaining it. The “B” engines have the 1800 hour tbo (or longer).  A TSIO-360-F would be a 1400 hour tbo engine, and FB would be 1800.  Here is the third-party article http://www.knr-inc.com/shoptalk-articles/25-shoptalk/21-201012-flying-a-360

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9 hours ago, carusoam said:

MAPA is a pretty reputable resource... but...

Know the author?

What made him say something like that...?

If all things we’re priced the same... walking by the lesser versions is easy...

It is really helpful to have the live discussions with explanations like what JL just supplied...

You are now an educated consumer on this topic!

Best regards,

Link to MAPA Article Did not see authors name http://www.mooneypilots.com/mapalog/M20K231 Eval Files/M20K231_Eval.htm

 

9 hours ago, carusoam said:

-a-

 

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Just for fun I looked at that MAPA article, I had not read it in awhile.  There is a lot of good information and a couple of pieces that in my view are not so good.  The two that stuck out to me as not so good, are the advice to lean to 1400 TIT during the climb, and to cruise at TIT plus 50 rich.  What is missing from the article, is what kind of CHTs the test pilot was getting with those settings.  We just had another thread where the advice from one of the factory pilots was to let the CHTs go no higher than 20 dF below redline.  Redline is 460, the engine should not be operated anywhere near those kinds of temps.  We now know that TIT plus 50 rich is about the worst mixture setting to run the engine at.  I do not lean at all during the climb, climb is full power full rich, 120KTAS, note that is true, not indicated.  And there is the problem, if the engine was consistently run at TIT plus 50, or if it was leaned during the climb and consistently saw CHTs above about 410, then book TBO is not a very good number to rely on, and if the engine is approaching 1000-1200 and has not had a top, you will be looking at doing a top overhaul pretty soon.

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16 minutes ago, jlunseth said:

Just for fun I looked at that MAPA article, I had not read it in awhile.  There is a lot of good information and a couple of pieces that in my view are not so good.  The two that stuck out to me as not so good, are the advice to lean to 1400 TIT during the climb, and to cruise at TIT plus 50 rich.  What is missing from the article, is what kind of CHTs the test pilot was getting with those settings.  We just had another thread where the advice from one of the factory pilots was to let the CHTs go no higher than 20 dF below redline.  Redline is 460, the engine should not be operated anywhere near those kinds of temps.  We now know that TIT plus 50 rich is about the worst mixture setting to run the engine at.  I do not lean at all during the climb, climb is full power full rich, 120KTAS, note that is true, not indicated.  And there is the problem, if the engine was consistently run at TIT plus 50, or if it was leaned during the climb and consistently saw CHTs above about 410, then book TBO is not a very good number to rely on, and if the engine is approaching 1000-1200 and has not had a top, you will be looking at doing a top overhaul pretty soon.

Agreed, turbos shouldn't be leaned in the climb. Climb full rich all the way to cruise altitude. For me that is often in the mid 20's flight levels. Once there I either run at 75% power for 100 ROP for speed or 65% power and 25 to 50 LOP for economy and range.

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