PDA

View Full Version : Would you by this engine?


Greg Copeland
May 19th 07, 01:22 AM
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

Newps
May 19th 07, 01:57 AM
It's a Lycoming, compression is always good. You need to check the cam.
Lyc's lose their cams without use.

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
>

Peter R.
May 19th 07, 02:03 AM
On 5/18/2007 8:22:50 PM, Greg Copeland wrote:

> The
> owner refuses to negotiate on the basis of these concerns and leaves
> me nothing to mitigate some of the potential risk.

With the glut of aircraft on the market I would suspect you will find a much
less risky purchase.

From what I have learned over the last six years as a single engine aircraft
owner, I would walk away from this sale without a second thought. You have
every right to be concerned about an engine that has seen such little use
over such a long period of time.


--
Peter

Ron Rosenfeld
May 19th 07, 02:17 AM
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

John Galban
May 19th 07, 02:40 AM
On May 18, 5:22 pm, Greg Copeland > wrote:
>
> 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?
>

Oil analysis is a trend tool. Even the folks that sell the service
will tell you that. A single oil analysis won't tell you much unless
the engine is shedding a prodigious amount of metal (which you should
be able to see by cutting open the oil filter). On Lycs that don't
get much use, I'd pull a cylinder or two and inspect the cam directly.

I know too many people that have bought underused engines that
looked good at inspection, only to have the results of internal
corrosion start showing up after they started flying it regularly.
Personally, with the airplane market heavily favoring the buyer these
days, I'd look elsewhere. This engine might be quite servicable, but
the seller is asking you to stake your money that it is. There's no
down side for him.

John Galban=====>N4BQ (PA28-180)

Orval Fairbairn
May 19th 07, 04:18 AM
In article om>,
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

I would assume that the engine should be torn down and overhauled.
Lycomings, especially, suffer from #1 and #2 cam erosion, due to
condensation in the upper front of the crankcase. Oil analysis may or
may not spot a problem here.

Cylinders may be pitted due to condensation/atmospheric pumping.

Some Hartzell propellers have a mandatory 5 year inspection cycle.

If the plane has sat outside, airframe components may suffer from
corrosion. Paint may need replacement.

Bob Noel
May 19th 07, 06:21 AM
In article om>,
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.
[snip]
> The
> owner refuses to negotiate on the basis of these concerns and leaves
> me nothing to mitigate some of the potential risk.
[snip]
> Comments? Would you consider such a deal? The mechanic's advice seem
> sound?

I wouldn't buy this airplane unless it was priced as a runout engine AND
I wanted a runout. But it sounds like the owner doesn't want to appropriately
acknowledge the time since overhaul.

Unless you are looking for a rare bird, patience will be rewarded. A friend
of mine spent almost three years looking for a cherokee 180 and found a
real beauty. It had the original engine and some 1700 TTSN. IOW it was
WAAAY beyond calendar TBO. He got about 5 years before he had to
overhaul it. And now he has a very low time 180 with a low time engine.

Anyway. Good luck

--
Bob Noel
(goodness, please trim replies!!!)

Ron Natalie
May 20th 07, 12:00 PM
Newps wrote:
> It's a Lycoming, compression is always good. You need to check the cam.
> Lyc's lose their cams without use.
>
Believe me, the compressions were great on my engine up until the time
the cylinder blew. As Newps says, you need to take a look inside.
I'd particularly be worried about corrosion (cam and cyl) on an engine
that flies infrequently.

Roy Smith
May 20th 07, 02:10 PM
Orval Fairbairn > wrote:
> Lycomings, especially, suffer from #1 and #2 cam erosion, due to
> condensation in the upper front of the crankcase.

Curious. Why would you get more condensation in the upper front part of
the crankcase than anywhere else?

Orval Fairbairn
May 20th 07, 03:00 PM
In article >,
Roy Smith > wrote:

> Orval Fairbairn > wrote:
> > Lycomings, especially, suffer from #1 and #2 cam erosion, due to
> > condensation in the upper front of the crankcase.
>
> Curious. Why would you get more condensation in the upper front part of
> the crankcase than anywhere else?

That is the area where ventilation is least -- also, the highest point
of the inside of the crankcase when the aircraft is at rest.

Dave[_3_]
May 21st 07, 02:50 AM
And....

When preheating, the metal propeller is a HUGE heat radiator, keeps
the front of the engine cooler than the rest, hence more
condensation in that area....

Some get mittens for their props... :)

Dave


On Sun, 20 May 2007 14:00:11 GMT, Orval Fairbairn
> wrote:

>In article >,
> Roy Smith > wrote:
>
>> Orval Fairbairn > wrote:
>> > Lycomings, especially, suffer from #1 and #2 cam erosion, due to
>> > condensation in the upper front of the crankcase.
>>
>> Curious. Why would you get more condensation in the upper front part of
>> the crankcase than anywhere else?
>
>That is the area where ventilation is least -- also, the highest point
>of the inside of the crankcase when the aircraft is at rest.

John Taylor[_2_]
May 21st 07, 11:04 PM
Greg,

You might mention what state or climate the plane has lived in, in terms
of moisture and how the plane was flown, if you can ascertain that.

I think the seller probably deserves more for his plane than a run-out-
engine price, but less than if the hours went on more quickly. Maybe
think in terms of valuing a 1400-hour engine.

There are a lot of planes out there with 15+ y.o. engines. The earlier
poster's advice is good: make your offer and see if there's a match.
The only reason not to make an offer is if you feel that the engine's
not safe without an overhaul first. In that case, buyer and seller
probably won't agree on a price.

If your mechanic can get a look at the cam, all the better. I probably
wouldn't spend more than 1-2% of the plane value on a pre-purchase
inspection, especially if you don't have a good agreement first.

Good luck!

-John

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
>

Google