General question about engines

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pequeajim

Well-Known Member
Joined
Sep 11, 2005
Messages
45
Location
New Holland, PA
As I understand things, Lycomings have a TBO associated with each engine model. That number is usually something like 2000, OR some duration of time like 12 years, whichever comes first.

My question is... When does the clock start, after purchase, or after initial certification? I mean, if you buy a new engine 10 years ago and it is in storage waiting to be installed, do you only have two years left before you have to overhaul it, even tho the engine only has 100 hours on it?
 

orion

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Joined
Mar 2, 2003
Messages
5,800
Location
Western Washington
For most certified aircraft the TBO (time between overhaul) is a recommended number, not an absolute. The actual running time that you'll get out of the engine however is heavily dependant on use and maintenance. Simply said, the more you use the airplane, the more likely you're going to reach the 2,000 hours or beyond. I've known aircraft owners who fly frequently, who have engines with 3,000 plus hours with no problems, low oil consuption and compression numbers as good as when it was new. And like many, I've also known many owners (including recently myself) who never reached even half of the TBO before needing a total rebuild.

The time starts when you start using it in the airplane (actual running or tach time) however, if the engine has sat for an extended period of time, it is highly likely that it will need at least a disassembly inspection since lack of use tends ot lead to the most likely source(s) of damage like rust and/or deterioration of seals.
 

pequeajim

Well-Known Member
Joined
Sep 11, 2005
Messages
45
Location
New Holland, PA
Thanks for the reply Orion. I was hoping for an answer in that direction. SInce this engine is in a Murphy Rebel, it is not likely to get the run time that I might have put on something like an RV with cross country in mind.

I will be a LONG time before I put 2000 hours on this engine.
 
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