.stuff snipped
I've known numerous pilots that have rescued ramp queens that had been
sitting for years. Most of the engines "ran fine" soon after the
resurrection was complete. It was usually 50-100 hrs. down the road that the
corrosion damage to the cam got bad enough to be obvious.
.stuff snipped

I am wondering if it would be considered in bad taste to ask a
prospective seller to produce his/her personal logbook (or the books of
those flying the beast) in order to establish the plane's flying
history? You can check the plane's books to get a history of hours
between annuals.

A concern we had when buying was that the plane (74 Cherokee 140 - 150hp
0-320) had a history of being purchased, being flown for 30-40 hours
(usually over a year's time), and then sold again. The thing had also
had a field overhaul 400 hours into its life for a prop strike. What
saved us from having too big a risk was that the previous owner to us
trained in it for 150 hours of fairly regular flying. He spent a fortune
replacing things, including one cylinder. If it was going to go South,
it would have likely done so with him. We got it at 1200 hours since new
(and 20 years) but it was really an 800SMOH/17 years engine. Normally,
those numbers can be disastrous. But, we got the plane to 1800 hours
before it finally was burning a quart an hour and compressions sagged.

Looking back, I am amazed the thing got that far towards TBO. With
moderate abuse (not flying), it ran for 1400 hours before compressions
went down and oil usage was at the limit. It appears that it never sat
quite long enough to do the Lycoming cam scrub self destruct thing.

Ironically, the owner moved up to another low time Piper, this time with
an 0-360 in a Cherokee 180. Within weeks, it started to idle a bit rough
and it turned out that one cam lobe was nearly gone. So, he dodged the
bullet with the plane he sold us and got it on the next one. Weird luck.

Of course, as newbies to airplane ownership 13 years ago, we knew
nothing of the risks we were taking back then. I remember only thinking
that the plane had not flown a lot of hours in all those years based on
a book I read about buying airplanes. And, it turned out O.K. Maybe that
is why we get into such disagreements on this group when someone gives
out advice that seems to counter another's experience. It really IS a
crap shoot with these engines.

Good Luck,
Mike