Does an overhaul un-lemon an engine?

On 9-May-2005, xyzzy wrote:

If an engine has been overhauled 3 times, never making TBO either time
(not even making it to 1/2 of TBO 2 of the times), should I be concerned
that it might be a lemon, or if the current overhaul was done right and
the engine has been treated right since then, should I not worry about
how it did before this overhaul?


The keys, I think, are who did the current overhaul and to what standards it
was done.

If the work was done by a quality shop with a good reputation, that is one
encouraging sign. If it was slapped together by some obscure A&P working
out of his garage, that's another story.

But the real question is what standard was used to determine reuse or
replacement of engine parts. Many of the best overhaulers will not try to
reuse cylinders, although it's perfectly legal to do so. In fact, any part
meeting minimum service tolerances can legally be reused in an overhaul.
But a "premium" overhaul will only use critical parts that meet "new"
tolerances. Of course, the cost difference between the two extremes can be
huge, as can resulting service life.

--
-Elliott Drucker