Wellll...

The engine in our 172 was pulled this spring 'cause some
metal started coming of the rear most cam lobe...

2740 hrs...

All but the last 80 hrs were in flight training, (running
whenever the sun shone over a period of 4 yrs)..

Was a shame, running very smooth & strong, compression in high
70's....great oil press...

The inspections required for running it "on condition" were a
cost factor tho... so we yanked it at the 1st sign of (confirmed)
metal...

There was a certian amount of comfort in flying behind an
engine subjected to such rigorous attention that is required during
"on condition" time...

Fly it...and pay attention to it,, especially the
accessories, THEY seldom go the distance whereas the "engine"
probably will.. (at least a 320)

Dave


On 3 Nov 2004 10:25:09 -0800, (Wolfgang) wrote:

Is anyone aware of statistical or other data that would indicate what
percentage of engines make it well beyond the factory specified TBO,
and how much longer they can be flown safely? I worry about sudden
engine failure due to metal fatigue.

Many of the small Lyc. engines have a TBO of around 2,000 hours. My
O-320-D3G (TBO 2,000hrs) has now 2,200 hrs since new, it's never been
opened for any reason. Of the above time, 1,100 hrs have been flown in
my RV-6.

I change oil (15W50) and full-flow filter every 50 hrs, cut-open the
filter for inspection, and have the oil analyzed. The compression is
still in the mid-70s.

I plan to continue flying until any of oil analysis/compression/oil
consumption would indicate a noticeable departure from their historic
values.
But the one other thing I worry about is the matter of metal fatigue,
which would not be indicated by any of the factors that I am
observing, but which could lead to engine stoppage.
If you have any data to support using these engines past their TBO it
would be much appreciated.