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

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

On 01/12/06 11:08, Andrew Gideon wrote:
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


If you can get your hands on a copy, try The Major Overhaul by Kas Thomas.
It really covers all the questions you're asking, and is a pretty great read.

I see it offered for sale he

http://www.aviationworld.net/product.asp?pID=5545&cID=13&c=123342

I bought my copy from http://aviationbook.com, but don't see it when
looking at their site today.



--
Mark Hansen, PP-ASEL, Instrument Airplane
Sacramento, CA

Andrew Gideon wrote:

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

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.


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

Yeah, I think all the field-overhaulers do that anyway. You won't really find
anyone offering anything less. You might be able to choose whether to overhaul
the cylinders or replace with new. The price might be pretty close either way.


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

Yeah, only the factory can zero-time an engine. IMO it's not technically any
better than any other overhaul, and might be not as good. It will cost you more.
You'll get a brand-new fresh logbook (whoopee!). If you're looking to sell, some
uninformed buyers might place a premium on a zero-timed engine.


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


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?

You can do it either way. If you have a local shop do the R&R and ship the
engine to the overhauler, you will pay shipping and the cost of crating the
engine. OTOH, you'll be building a relationship with your local shop that might
prove valuable later.

Dave

Mark Hansen wrote:

If you can get your hands on a copy, try The Major Overhaul by Kas Thomas.
It really covers all the questions you're asking, and is a pretty great
read.

I see it offered for sale he

http://www.aviationworld.net/product.asp?pID=5545&cID=13&c=123342

I bought my copy from http://aviationbook.com, but don't see it when
looking at their site today.

Agree this book is a valuable resource for anyone contemplating an overhaul.

Dave

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.

Ross

Andrew Gideon wrote:
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

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

Marco

"Dave Butler" wrote in message
news:1137100239.132100@sj-nntpcache-5...
Andrew Gideon wrote:

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

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.




Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
** SPEED ** RETENTION ** COMPLETION ** ANONYMITY **
----------------------------------------------------------
http://www.usenet.com

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.

IIRC the big deal with Lyc a while ago was that they changed their policy on
cases. Field-welded cases had always been acceptable, but they changed their
policy without notice so that they denied the core charge on cases that had ever
been welded.

Given the age of our engines, a lot of them have had welded cases at one time or
another.

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

Dave

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?

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?

[...]
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"?

- Andrew

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?


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?

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?

Thanks again...

Andrew

On 01/12/06 14:41, 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?

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?

[...]
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"?

.... and under what conditions might you not give me what you initially
agreed.


- Andrew



--
Mark Hansen, PP-ASEL, Instrument Airplane
Sacramento, CA