Overhaul of 180HP Lycoming 0-360-A4M in a Skyhawk (C-172)

On Thu, 12 Jan 2006 14:08:59 -0500, Andrew Gideon wrote:

I'm curious what others have done, and how its worked for them. I've been
doing some of reading of articles, but it's raised more questions than
answers. Questions I do need, but I'd also like some of those answers.

Questions bouncing around head include:

Hi Andrew,

My experiences with an overhaul is as follows on a Sundowner. Some of what
follows are based on what "I was told"....

Should we get our engine overhauled, or swap it for a previously overhauled
engine?

I was advised on my engine that had 2140 hours to overhaul it especially
due to the low time on the crankcase. Keep a perfectly working crankcase.

If we do overhaul, is "to new specifications" the only reasonable choice?

I *think* overhauls are to new specs?

Is there a difference of significance between "factory rebuilt" (zero-timed)
and "overhauled to 'new specifications'"?

Price would be the difference from what I was told. Also, you get to start
your engine log book at zero hours. I went for the overhaul on my
Sundowner as it was 7K difference. Mighty big difference for the price of
a new log book....

Any recommendations for shops for the overhaul (or shops to avoid)?

Nope, sorry don't have any. Mine was done in FL. No problems encountered.

Finally, I'm confused about the process. Does one shop remove/replace and
another actually do the engine work? Or does the plane need to be flown to
the shop that either does the overhaul or has the engine to swap?

My A&P pulled the engine out, and FEDEXED it to the shop in FL. Down time
was 3 1/2 weeks.

Overall, for me, it was a positive experience. 13.5K for engine and labor.
For the piece of mind of knowing who is behind this engine for break in,
well worth every penny.

Hope this helps.

Allen

Ross Richardson wrote:
I got a Lycoming factory overhauled O-360-A1A and had it delievered to
my A&P/IA shop. There he and I installed the new engine on my '65
Skyhawk.. I sent the other one back for the "core" charge. I had to
leave a large deposit with Lycoming, that they quickly refunded when the
old engine arrived. Learing experience for me. 300 hours later, running
fine.

We had a similar experience getting a factory overhauled Lycoming
engine through Air Power two years ago. For the core charge, we sent
them a certified check which they held uncashed and sent back to us
when they received the old engine back. The engine has been running
great for the last 350 hrs.

Hai Longworth

Andrew Gideon wrote:
Dave Butler wrote:


If downtime is crucial, you can get a faster turnaround on an engine swap
than overhauling your engine. When you swap, you're taking pot-luck on the
case, crank, and cam. If your case, crank, and cam are known good, you
might want to hang onto them. If they're suspect, you might improve
yourself by taking pot-luck.


What does "known good" mean here? "Never had a problem with"? Or is there
some analysis involved?

It's pretty hard to know with any precision. In the absence of any operational
problems, about the only information you have is whether it's first run (never
been overhauled), etc., whether any regrinding has ever been done, whether the
case has ever had any welding done on it.


Any recommendations for shops for the overhaul (or shops to avoid)?

Sorry, I don't know the shops in your area. Ask all the nearby FBOs where
they send their engines for overhaul. Probably there will be a consensus.
Pick a shop nearby.


Are you speaking here of the shop doing the R&R or the shop doing the
overhaul itself? Or both shops?

Probably if there's a warranty problem, the R&R shop is going to refer you to
the overhauler (unless the problem is with the R&R, of course). The R&R shop may
or may not intercede on your behalf with the overhauler. If there are two shops
involved, that might be something you want to discuss beforehand. How are
warranty issues handled?

Of course, each shop will say they will stand behind whatever work they do, but
if the overhauler is remote, will the R&R shop work with you to resolve issues
with the overhaul?

If so, is the time to resolve the overhauler's problem billable by the R&R shop?
If you go to a local shop and they sell you a turnkey overhaul where they pick
the overhauler, the local shop should stand behind everything. If you go to a
local shop for the R&R and shop separately for the actual overhaul, the R&R shop
may not take any responsibility for the overhauler's warranty.


Warranty service by long-distance telephone is a PITA.
Much better if you can get the plane to the shop (for warranty service).


Hmm...WRT warranty work, would that be dealing with the R&R shop or the
overhaul shop?

See above. The reason I raise this issue is because of my experience with my
very first overhaul. My partner was a more seasoned owner than I was at the time
and he recommended a nationally known overhauler 2/3 of the way across the
country. There was a problem when the engine came back, and a lot of billable
time was wasted by the local R&R shop resolving the problem. In retrospect, the
overhauler did everything he was supposed to do and perhaps more, but the
problem was just exacerbated by the distances involved. Had we been able to just
fly the plane to the overhauler, I'm sure it could have been quickly resolved.

Dave

Andrew Gideon wrote:
Dave Butler wrote:


Marco Leon wrote:

I thought Lycoming was charging back for bad cranks and cams?

Any overhauler is going to deny the core charge if the parts are
unrepairable.


I think I understand that "core charge" is money paid for the value of the
engine after it is removed. I think what you're discussing above is
Lycoming failing to pay this value for engines they receive [in certain
cases]. Yes?

Yes.


How does this "core charge" impact my overhaul? If I choose to overhaul my
engine, does it play a role? If I choose to buy an engine off the shelf,
then I suppose this "core charge" is what I get for returning my existing
engine?

The core is calculated separately for case, crank, and cam. The quote you get
for an overhaul assumes all are repairable. If they are not, then you will pay
the core charge.


[...]

I don't know whether field-overhaul shops are still accepting welded
cases, or if they've followed Lycoming's lead.


Ah, so one question to ask is "if I buy an engine from you, what will you
give me for my engine"?

The usual assumption on price quotations is that you are trading in a repairable
case, crank, and cam. But, yes, of course, ask.

Dave

Longworth wrote:

We had a similar experience getting a factory overhauled Lycoming
engine through Air Power two years ago. For the core charge, we sent
them a certified check which they held uncashed and sent back to us
when they received the old engine back. The engine has been running
great for the last 350 hrs.

Does this "core charge" thing work similarly if one deals not with the
factory but with some "shop" that does the work? Or is Lycoming still
involved somehow?

- Andrew

My A&P was able to order mine directly from the factory. I had to wait
fo the skys to open after 9/11 so I could test fly and break in.

Ross

Longworth wrote:
Ross Richardson wrote:

I got a Lycoming factory overhauled O-360-A1A and had it delievered to
my A&P/IA shop. There he and I installed the new engine on my '65
Skyhawk.. I sent the other one back for the "core" charge. I had to
leave a large deposit with Lycoming, that they quickly refunded when the
old engine arrived. Learing experience for me. 300 hours later, running
fine.


We had a similar experience getting a factory overhauled Lycoming
engine through Air Power two years ago. For the core charge, we sent
them a certified check which they held uncashed and sent back to us
when they received the old engine back. The engine has been running
great for the last 350 hrs.

Hai Longworth

Article in LPM this month about overhaul shops having test beds/stations. I
haven't read it all yet, but the consensus was to make sure your shop can
run the engine after they complete the job.
Jim

I would agree.

I had mine done by a shop that didn't test run it. I was the test pilot.
Everything worked out fine but next time I'll probably have the engine run
in a test cell.


"Jim Burns" wrote in message
...
Article in LPM this month about overhaul shops having test beds/stations.
I
haven't read it all yet, but the consensus was to make sure your shop can
run the engine after they complete the job.
Jim

Maybe a related question.
How to make the decision to actually DO an overhaul/replacement?
In some cases it is exceedingly clear - lots of metal in oil, oil usage,
cylinders blown, etc.
But what about the high time engine that is otherwise working just fine?
Compression good. Oil clean. not burning excessive oil.
Due to a prop strike, my lycoming IO360 was torn down at 1300 hours. Since
it was in pieces, we did more than a 'normal' sudden stoppage inspection.
Bearings, cam recondition, rings, etc etc.
Engine is now at 2400 hours (2000 tbo). Runs fine. No change in oil
consumption or fuel consumption. Good compression. Do we wait for bad stuff
to happen, or be proactive. Frankly, I am concerned about taking an engine
that 'ain't broke' and either overhauling it or replacing it and ending up
with problems when today I don't have any.

any advice on how to know when 'It's time'?
"Andrew Gideon" wrote in message
online.com...

I'm the "plane lt." for a skyhawk, based in northern NJ (KCDW), that's
getting ready for its engine overhaul. What should we do with it?

I'm curious what others have done, and how its worked for them. I've been
doing some of reading of articles, but it's raised more questions than
answers. Questions I do need, but I'd also like some of those answers.

Questions bouncing around head include:

Should we get our engine overhauled, or swap it for a previously
overhauled
engine?

If we do overhaul, is "to new specifications" the only reasonable choice?

Is there a difference of significance between "factory rebuilt"
(zero-timed)
and "overhauled to 'new specifications'"?

Any recommendations for shops for the overhaul (or shops to avoid)?

Finally, I'm confused about the process. Does one shop remove/replace and
another actually do the engine work? Or does the plane need to be flown
to
the shop that either does the overhaul or has the engine to swap?

For others asking similar questions, here's some of what I've read:

http://www.mattituck.com/new/articles/ohterms.htm
http://www.avweb.com/news/maint/185049-1.html

http://www.aviation-consumer.com/arc...rt/4718-1.html

I've also looked through the forums on cessna.org, but I cannot relocate
what I'd previously found there.

Thanks...

Andrew

Thats a tough call.....

Our 172 was purchased from a training school that put 2500 hrs on it
in 4 years.

It started making metal at 2792 hrs. (aft cam lobe)

Was using a liter of oil/12 hrs, comps 72 - 75, good oil pressure,
pulled great..

Replaced engine, could not tell the difference in oprn or
performance..

At the flight school, if they could see, they flew.. the aircraft was
very agressively maintained. Cosmetically, it was rough, but
mechanically, no concerns, Annuals.... cowl fasteners and a manifold
flange leaking (exhaust) were the biggies. Squawked one time for a
noisy wheel bearing.

Dave



On Fri, 13 Jan 2006 17:17:09 -0500, "pgbnh"
wrote:

Maybe a related question.
How to make the decision to actually DO an overhaul/replacement?
In some cases it is exceedingly clear - lots of metal in oil, oil usage,
cylinders blown, etc.
But what about the high time engine that is otherwise working just fine?
Compression good. Oil clean. not burning excessive oil.
Due to a prop strike, my lycoming IO360 was torn down at 1300 hours. Since
it was in pieces, we did more than a 'normal' sudden stoppage inspection.
Bearings, cam recondition, rings, etc etc.
Engine is now at 2400 hours (2000 tbo). Runs fine. No change in oil
consumption or fuel consumption. Good compression. Do we wait for bad stuff
to happen, or be proactive. Frankly, I am concerned about taking an engine
that 'ain't broke' and either overhauling it or replacing it and ending up
with problems when today I don't have any.

any advice on how to know when 'It's time'?
"Andrew Gideon" wrote in message
gonline.com...

I'm the "plane lt." for a skyhawk, based in northern NJ (KCDW), that's
getting ready for its engine overhaul. What should we do with it?

I'm curious what others have done, and how its worked for them. I've been
doing some of reading of articles, but it's raised more questions than
answers. Questions I do need, but I'd also like some of those answers.

Questions bouncing around head include:

Should we get our engine overhauled, or swap it for a previously
overhauled
engine?

If we do overhaul, is "to new specifications" the only reasonable choice?

Is there a difference of significance between "factory rebuilt"
(zero-timed)
and "overhauled to 'new specifications'"?

Any recommendations for shops for the overhaul (or shops to avoid)?

Finally, I'm confused about the process. Does one shop remove/replace and
another actually do the engine work? Or does the plane need to be flown
to
the shop that either does the overhaul or has the engine to swap?

For others asking similar questions, here's some of what I've read:

http://www.mattituck.com/new/articles/ohterms.htm
http://www.avweb.com/news/maint/185049-1.html

http://www.aviation-consumer.com/arc...rt/4718-1.html

I've also looked through the forums on cessna.org, but I cannot relocate
what I'd previously found there.

Thanks...

Andrew