On 18 May 2007 17:22:54 -0700, Greg Copeland wrote:

I've been shopping for a plane for a while. I'm hoping I found the
one but the engine has given me pause. The engine is 17-years old.
It has ~700 hours on it. The average per year is only 49hr/year. Two
years during that 17, the plane did not fly and I'm guessing it was
not pickled. The latest it sat was in 2000. During the last 6 years,
the plane has mostly flown some 32hrs/year on average. The engine is
a Ly IO-360-A1A. Compression on the engine is 74, 76, 74, 76. The
owner refuses to negotiate on the basis of these concerns and leaves
me nothing to mitigate some of the potential risk.

I spoke with a local mechanic today and his opinion is that it should
give pause but the engine may be fine and was seemingly encouraged by
the compression numbers. He recommends an oil analysis. His opinion
is the biggest potential unseen danger stems from the cam and an oil
analysis would address this concern one way or the other.

Comments? Would you consider such a deal? The mechanic's advice seem
sound?


Greg

This really falls into the area of negotiating strategy rather than "would
you buy this engine".

In your position, I would figure out how much *I* thought the plane might
be worth assuming the engine will require a complete overhaul, including
accessories, fuel and oil lines, mounts, cooler overhaul, etc. Possibly a
prop overhaul also? Or maybe the Hartzell prop hub needs to be replaced
because of the new A/D?

Then I would inform the seller how much I would be willing to pay for his
aircraft. I would not necessarily go into any details as to how I arrived
at that figure, although I might depending on the specifics of what
happened next.

It is the seller's right to ask whatever he wants for his airplane, and it
is my right to not pay any more than I want to. But, if you run the
numbers, you might discover that his asking price is such that you can live
with it, even with overhauling the engine right after purchase.

So far as oil analysis being able to predict whether a new cam will be
required in the next 25 hours or so -- it won't. And I've flown behind a
Lyc IO360A1A for the past 30 years or so, and gone through several
camshafts during that time!

FWIW, Lycoming recommends overhaul of that engine at 12 years, if it has
not met the flight time limits. Of course, under Part 91 non-commercial
flying, it is perfectly *legal* to overhaul "on-condition".

But I would only purchase that aircraft assuming I was going to do a
firewall forward overhaul soon after.

I would not rely on the "local mechanic's" opinion to conclude that the
engine will not require an overhaul in the near future. (Unless he's
willing to give you a warranty, and you think you can enforce it, of
course).

Good Luck!
--ron