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Tiger Moth engine overhaul

Posted By:
Frank Gregory
2
Posts
0
#1 Posted: 8/29/2010 15:19:05

Does anyone know the  TBO  of the Gypsy Major engine in the tiger moth aircraft.  I can't seem to find it online without buying a manual..Just need to know for purchase ideas. Thanks  Frank



John Johnson
Homebuilder or Craftsman
14
Posts
2
#2 Posted: 9/2/2010 21:03:26

Probably around 500 hours if there is even one established!  My 1943 Lycoming has a TBO of about 700 hours.  I had a bit over 2500 hours on the last major when I pulled the cylinders off it a couple of years ago.  All nine cylinders checked out within new cylinder tolerance.  I replaced one exhaust valve and one valve guide and reused all nine cylinders.

 

TBO have virtually NO meaning unless an airplane is used under Part 135 or Part 121.   The hours portion of the TBO is particularly meaningless for private use for most people.  A TBO of 2000 hours or 12 years, whichever comes first, will mean that most new Lycoming engines will reach TBO with far less than 2000 hours on them.

 

The accepted practice for private aircraft is to run the engine until it shows need for service or overhaul.  The compression will be shot, the valves will leak, or it will not develop anywhere near the rated power, then overhaul it.

I own a Piper Apache that has 600 hours on the engines since new.  They are the original engines.  These low time engines were pickled by Piper for several years, but they probably reached their "TBO" forty years ago.  They are still "low time engines".  :-)

Do not be misled by claims of low time on older engines.  If it checks out as a good engine, it is probably a good engine.  Do not expect the impossible.  Remember, new cars of that vintage were expected to be ready for at least a valve job after about 40,000 miles. 

 



Frank Gregory
2
Posts
0
#3 Posted: 9/3/2010 04:41:58

Thanks, I was looking at the tiger moth that was for sale and had been used for rental but the sale price of 45 seamed low. The owner did not want to pay for any overhaul as it was used for rental so he had to sell or park it. I finally had to pay to buy a caa manual on the engine that did list a 5oo hr check and 1800 hr tbo so you are in the ballpark. I think I will pass on this one because tbo cost are high on this engine and my cost would pretty much double.Thank You