Oil leak on top of the engine

In article 6q3Pd.63958$eT5.59714@attbi_s51,
"Jay Honeck" wrote:

The point I'm trying to make is it appears that some bolts being torqued
have been overlooked and what is the chance that the cylinder nuts & thru
bolts had been overlooked also?

Simply, You don't know until you check. It'll require 10 minutes if you
have easy access to the engine.

I'm having my shop check these this morning.

To those who think that the bolt might have been loose from the start,
remember: I watched the shop build this engine, and I personally saw them
check the torque on the engine case bolts. They *were* tightened to spec.

I also know that they never re-checked them, however, and my main mechanic
has admitted that they never check these as a matter of course.

In the case of the O-540, anyway, the case bolts are torqued surprisingly
low, and they are not secured in any way. No cotter pin, no safety wire, no
LocTite, no lock washer -- NOTHING prevents those nuts/bolts from loosening
over time. It seems like a ridiculous over-sight, but that's the way it
is.

A guy on the Cherokee Chat actually had a case bolt FALL OUT after loosening
over time from vibration, so this is not an unheard-of problem. I'm
surprised it's never been addressed in this forum before -- at least not in
my 7 years here.

I've bought a torque wrench, and I'm going to be checking ALL of these bolts
every time I change the oil, from now on.


Another caveat on torquing (from an old AI): All torquing should be done
"wet", with a drop of oil to lube the nut, so as not to get a false
torque reading.

"George Patterson" wrote in message
...


Allen wrote:

You may want to check with your mechanic about this also. I think the
proper
way to check torque of a bolt is to loosen it first and then re-torque.

Nope. Just buy a modern wrench, set it to the bottom end of the proper
torque
range, and try to tighten the bolt. If the wrench "clicks" without the
bolt
turning, you're good to go. If the bolt turns first, call that to the
attention
of your mechanic.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

That will only tell you if the bolt is under-torqued. To make sure it is
torqued to a specific number it must be loosened first.

Allen

On 2/11/2005 11:01, Allen wrote:

"George Patterson" wrote in message
...


Allen wrote:

You may want to check with your mechanic about this also. I think the
proper
way to check torque of a bolt is to loosen it first and then re-torque.

Nope. Just buy a modern wrench, set it to the bottom end of the proper
torque
range, and try to tighten the bolt. If the wrench "clicks" without the
bolt
turning, you're good to go. If the bolt turns first, call that to the
attention
of your mechanic.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

That will only tell you if the bolt is under-torqued. To make sure it is
torqued to a specific number it must be loosened first.

Additionally, I think the bolt can "stick" in place - which may
fool the torque wrench. Loosening the bolt before torquing it would
solve this problem as well.



Allen




--
Mark Hansen, PP-ASEL
Sacramento, CA

Allen wrote:

That will only tell you if the bolt is under-torqued.

And that is all Jay needs to know.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

On Fri, 11 Feb 2005 14:36:50 GMT, "Jay Honeck"
wrote:

The point I'm trying to make is it appears that some bolts being torqued
have been overlooked and what is the chance that the cylinder nuts & thru
bolts had been overlooked also?

Simply, You don't know until you check. It'll require 10 minutes if you
have easy access to the engine.

I'm having my shop check these this morning.

Good for you.

To those who think that the bolt might have been loose from the start,
remember: I watched the shop build this engine, and I personally saw them
check the torque on the engine case bolts. They *were* tightened to spec.

New bolts, new nuts, new lock washers, torque wrench calibrated
recently?

I also know that they never re-checked them, however, and my main mechanic
has admitted that they never check these as a matter of course.

Tsk, tsk! What else do they not do?

In the case of the O-540, anyway, the case bolts are torqued surprisingly
low, and they are not secured in any way. No cotter pin, no safety wire, no
LocTite, no lock washer -- NOTHING prevents those nuts/bolts from loosening
over time. It seems like a ridiculous over-sight, but that's the way it
is.

If all of the engines would have failed, they would have changed the
procedure. Something else is wrong.

A guy on the Cherokee Chat actually had a case bolt FALL OUT after loosening
over time from vibration, so this is not an unheard-of problem. I'm
surprised it's never been addressed in this forum before -- at least not in
my 7 years here.

I've bought a torque wrench, and I'm going to be checking ALL of these bolts
every time I change the oil, from now on.

Have it calibrated, and remember that each time you torque it, the
bolt stretches. Some years ago, when it was credible, AVWEB had an
article on torque. You can probably still pull it up.

On Fri, 11 Feb 2005 18:27:23 GMT, Orval Fairbairn
wrote:

In article 6q3Pd.63958$eT5.59714@attbi_s51,
"Jay Honeck" wrote:

The point I'm trying to make is it appears that some bolts being torqued
have been overlooked and what is the chance that the cylinder nuts & thru
bolts had been overlooked also?

Simply, You don't know until you check. It'll require 10 minutes if you
have easy access to the engine.

I'm having my shop check these this morning.

To those who think that the bolt might have been loose from the start,
remember: I watched the shop build this engine, and I personally saw them
check the torque on the engine case bolts. They *were* tightened to spec.

I also know that they never re-checked them, however, and my main mechanic
has admitted that they never check these as a matter of course.

In the case of the O-540, anyway, the case bolts are torqued surprisingly
low, and they are not secured in any way. No cotter pin, no safety wire, no
LocTite, no lock washer -- NOTHING prevents those nuts/bolts from loosening
over time. It seems like a ridiculous over-sight, but that's the way it
is.

A guy on the Cherokee Chat actually had a case bolt FALL OUT after loosening
over time from vibration, so this is not an unheard-of problem. I'm
surprised it's never been addressed in this forum before -- at least not in
my 7 years here.

I've bought a torque wrench, and I'm going to be checking ALL of these bolts
every time I change the oil, from now on.


Another caveat on torquing (from an old AI): All torquing should be done
"wet", with a drop of oil to lube the nut, so as not to get a false
torque reading.

Let's hope the old AI isn't doing much any longer. Whether a bolt is
wet or dry (oil, locktite,graphite) will change the torque specs. The
manufacturer should specify the condition of the bolt for those who
have their JD's.

Gene Kearns wrote:
snip

With reference to exterior case bolts, I am only passing along
information given to me at both the Lycoming and Continental factory
overhaul schools. I kinda thought they knew what they were talking
about. But, WTF do *they* know? If you feel comfortable never
checking
this, by all means, don't. It isn't specifically required by law.

And your point is what? I've allegedly spent 17 years maintaining GA
recips about 85%/15% Lyc/TCM, and have never been to a "factory
overhaul" school. During the last GA "factory" school I allegedly
attended, I had to explain to the "factory" TCM rep why he was getting
so many compliants concerning cold & hot engine starts on the Seneca V.

I can pretty much guarantee that I've allegedly hung, set-up and
maintained thru TBO removal more Lyc factory o-hauls, re-mans, and
probably new engines than any 15 owners that hang around in the
'groups. That does not take into account local o-hauls, other
name-brand o-hauls and customer aircraft that were purchased with who
knows whose o-haul is under the hood.

perspective of an alleged maintenance technician, so WTF do I know.

If this is some kind of knee-jerk reaction to my reference to
technician need-to-know, that was reference to knowledge and use of
Lycoming SI 1112 and SB 272, not checking the exterior case bolts. In
the instance of this particular engine running 500 hours (I think)
with some bolts (how many others?) finger tight... I think it would
be
a *great* candidate for checking for fretting corrosion by this
method
set forth in the manufacturer's service information.

However, since nobody wrote a specific law governing this, feel free
to use that calibrated elbow, tighten everything up, and send the
airplane to the flight line.... Hell, it'll be all right.....

If there was "some kind of knee-jerk reaction" it was to your statement
that it is common industry practice to either verify the
torque/re-torque case bolts at some periodic interval. That sir, is
bull****.

BTW, your shop pics are very impressive, perhaps some day I can take a
break from allegedly working full-time in somebody else's hangar on
somebody else's airplane, and have time to do something similiar.

TC

Allen wrote:

That will only tell you if the bolt is under-torqued.


George Patterson" wrote in message
...
And that is all Jay needs to know.

George Patterson
He who would distinguish what is true from what is false must have an
adequate understanding of truth and falsehood.

Not if he wants it done right. Over-torque has it's own problems associated
with it, such as the bearing pinch someone eluded to earlier.

Allen

"Jon A." wrote, "Some years ago, when it was credible, AVWEB had an article
on torque."

Jon,

Do you feel that AvWeb is no longer credible?

Jon

BIG snip of good stuff

If the only offending bolts were the top case bolts, then you are
probably going to be just fine. I have seen this happen before and it
was not the rebuilder's fault... it was the installer's..... for
playing around with the "hang-point" for engine installation.

Thanks, Gene, for the good information.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"