Lycoming SB for soft pin plugs

[Robert M. Gary]

I have an IO-360-A3B6 with 1000 SFNEW in 1998. We pulled a cylinder
and the pin plugs where gone (we guessed this from the oil analysis).
The mechanic says he thinks he remembers some sort of SB put out by
Lycoming that there was a defect in the plugs and that they were made
too soft. Has anyone heard of such an SB???

-Robert

[Dave Butler]

Robert M. Gary wrote:
> I have an IO-360-A3B6 with 1000 SFNEW in 1998. We pulled a cylinder
> and the pin plugs where gone (we guessed this from the oil analysis).
> The mechanic says he thinks he remembers some sort of SB put out by
> Lycoming that there was a defect in the plugs and that they were made
> too soft. Has anyone heard of such an SB???

http://www.lycoming.com/support/publications/service-instructions/pdfs/SI1492C.pdf

DB

[Robert M. Gary]

On Aug 16, 10:33 am, Dave Butler > wrote:
> Robert M. Gary wrote:
> > I have an IO-360-A3B6 with 1000 SFNEW in 1998. We pulled a cylinder
> > and the pin plugs where gone (we guessed this from the oil analysis).
> > The mechanic says he thinks he remembers some sort of SB put out by
> > Lycoming that there was a defect in the plugs and that they were made
> > too soft. Has anyone heard of such an SB???
>
> http://www.lycoming.com/support/publications/service-instructions/pdf...
>
> DB

Well, that's me. Now the cylinders are worn from the busted pin plugs.
That's at least one cylinder that will need to be replaced. I wonder
if Lycoming will offer any assistance ($$$) in addressing this since
the SI seems to acknowledge that the pin plugs were inproper.

-Robert

[Scott Skylane]

Robert M. Gary wrote:
> On Aug 16, 10:33 am, Dave Butler > wrote:
>
>>Robert M. Gary wrote:

> /snip/ I wonder
> if Lycoming will offer any assistance ($$$) in addressing this since
> the SI seems to acknowledge that the pin plugs were improper.
>
> -Robert
>

Robert,

HAAAHHAAAAAAHHAAAAA, that's a good one! Seriously, have you complied
with the SB religeously since it came out in July 2000? No? I didn't
think so. Not that it would matter, anyway. However, Lycoming will be
happy to sell you the new plugs and cylinders at full retail, and not a
penny more...

Happy Flying!
Scott Skylane
N92054

[Robert M. Gary]

On Aug 16, 9:55 pm, Scott Skylane > wrote:
> Robert M. Gary wrote:
> > On Aug 16, 10:33 am, Dave Butler > wrote:
>
> >>Robert M. Gary wrote:
> > /snip/ I wonder
> > if Lycoming will offer any assistance ($$$) in addressing this since
> > the SI seems to acknowledge that the pin plugs were improper.
>
> > -Robert
>
> Robert,
>
> HAAAHHAAAAAAHHAAAAA, that's a good one! Seriously, have you complied
> with the SB religeously since it came out in July 2000? No? I didn't
> think so.

Yes, I have (BTW Its not an SB, its an SI).

-Robert

[Jim Burns[_2_]]

I "think" the problem was when Lycoming switched from alum/bronze pin caps
to aluminum caps. I've been told there is no problem with either the
alum/bronze caps that preceded or followed the aluminum caps, nor is there a
problem with the aluminum "piloted" press fit ends that are pressed into the
pins. Superior also makes pins with press fit plugs, although they problems
with the pins cracking in an earlier version.

Superiors SL points out that you can not mix pins/plugs of different weights
on the same engine.

Can an A&P familiar with the different pins chime in?

Jim


"Robert M. Gary" > wrote in message
ups.com...
> On Aug 16, 10:33 am, Dave Butler > wrote:
> > Robert M. Gary wrote:
> > > I have an IO-360-A3B6 with 1000 SFNEW in 1998. We pulled a cylinder
> > > and the pin plugs where gone (we guessed this from the oil analysis).
> > > The mechanic says he thinks he remembers some sort of SB put out by
> > > Lycoming that there was a defect in the plugs and that they were made
> > > too soft. Has anyone heard of such an SB???
> >
> > http://www.lycoming.com/support/publications/service-instructions/pdf...
> >
> > DB
>
> Well, that's me. Now the cylinders are worn from the busted pin plugs.
> That's at least one cylinder that will need to be replaced. I wonder
> if Lycoming will offer any assistance ($$$) in addressing this since
> the SI seems to acknowledge that the pin plugs were inproper.
>
> -Robert
>

[[email protected][_1_]]

On Fri, 17 Aug 2007 08:14:50 -0500, "Jim Burns"
> wrote:

>I "think" the problem was when Lycoming switched from alum/bronze pin caps
>to aluminum caps. I've been told there is no problem with either the
>alum/bronze caps that preceded or followed the aluminum caps, nor is there a
>problem with the aluminum "piloted" press fit ends that are pressed into the
>pins. Superior also makes pins with press fit plugs, although they problems
>with the pins cracking in an earlier version.
>
>Superiors SL points out that you can not mix pins/plugs of different weights
>on the same engine.
>
>Can an A&P familiar with the different pins chime in?
>
>Jim

Pretty much nailed it. Minor nits, the piloted pins don't "press" in,
they slip in quite nicely until the inside of the pin gets varnished
up.

Every once in awhile they just start shaving. Have seen issues with
ALL the types in service.

Lycoming useta say "unofficially" that you could mix plug types if you
paired them in opposing cylinders.

Am curious what the OP or his tech found that requires cylinder
replacement.

Regards;

TC

[Robert M. Gary]

On Aug 17, 3:58 pm, wrote:
> On Fri, 17 Aug 2007 08:14:50 -0500, "Jim Burns"
>
> > wrote:
> >I "think" the problem was when Lycoming switched from alum/bronze pin caps
> >to aluminum caps. I've been told there is no problem with either the
> >alum/bronze caps that preceded or followed the aluminum caps, nor is there a
> >problem with the aluminum "piloted" press fit ends that are pressed into the
> >pins. Superior also makes pins with press fit plugs, although they problems
> >with the pins cracking in an earlier version.
>
> >Superiors SL points out that you can not mix pins/plugs of different weights
> >on the same engine.
>
> >Can an A&P familiar with the different pins chime in?
>
> >Jim
>
> Pretty much nailed it. Minor nits, the piloted pins don't "press" in,
> they slip in quite nicely until the inside of the pin gets varnished
> up.
>
> Every once in awhile they just start shaving. Have seen issues with
> ALL the types in service.

The shop is recommending pulling all cylinders and doing a top. Does
one cylinder having an issue with pin plugs mean others much (the IA
says so, I'm not sure). I'm thinking I just want to replace this
cylinder and then fly it. The oil analysis will show if there is
another plug wearing.

> Am curious what the OP or his tech found that requires cylinder
> replacement.

The IA said the cylinder was "2 one thousands" out of spec. Actually
one of the reasons we choose this cylinder to pull ( from the oil
analysis we knew we had to pull one of them do to progressively higher
AL counts), was that the cross hatching was gone on #1 (this is recent
because we boroscoped it at annual and didn't see this).
This engine has 1000 SFNEW in 1998 so I was not expecting to have to
replace cylinders. The IA did say that the bottom looks like a new
engine, no sign of any problems down there (we change the oil about
every 30 hours).
Anyway, the IA is recommending a full top and I'm not sure that is the
way to go.

-Robert

[Jim Burns]

> Pretty much nailed it. Minor nits, the piloted pins don't "press" in,
> they slip in quite nicely until the inside of the pin gets varnished
> up.

The pressed in plugs I refered to are factory pressed into the pins such as
the Superior SL13444-1. We ran across this type of pin on the last cylinder
we swapped on the Aztec. We pulled and pressed the plugs out of the old pin
just in case we needed it (we didn't, the new cylinder came with a pin) the
old plug stems were "fluted" and definately had been pressed into the pin.
The new pin confirmed the construction, it also had factory pressed in plugs
rather than caps.

From Superiors service letters:
To further improve the durability of the piston pin plug, Superior Air Parts
has now developed a new

piston pin assembly, the SL13444-1, for the 5.125 inch Textron Lycoming
cylinders. This new

assembly incorporates a heavy wall piston pin and two piloted plugs that are
press-fitted into the inside

diameter of the piston pin during manufacturing. Superior believes that the
use of the SL13444-1

piston pin assembly will provide greater engine reliability and durability
because it greatly reduces the

possibility of the plugs spinning in the piston pin.



Jim

[[email protected][_1_]]

On Fri, 17 Aug 2007 19:16:56 -0500, "Jim Burns"
> wrote:

I'll take your word for it. The only piloted ones that we ever saw
were the OEM Lycoming ones.

Wonder if it (having them pressed in) helped...

Regards;

Mark

>> Pretty much nailed it. Minor nits, the piloted pins don't "press" in,
>> they slip in quite nicely until the inside of the pin gets varnished
>> up.
>
>The pressed in plugs I refered to are factory pressed into the pins such as
>the Superior SL13444-1. We ran across this type of pin on the last cylinder
>we swapped on the Aztec. We pulled and pressed the plugs out of the old pin
>just in case we needed it (we didn't, the new cylinder came with a pin) the
>old plug stems were "fluted" and definately had been pressed into the pin.
>The new pin confirmed the construction, it also had factory pressed in plugs
>rather than caps.
>
>From Superiors service letters:
>To further improve the durability of the piston pin plug, Superior Air Parts
>has now developed a new
>
>piston pin assembly, the SL13444-1, for the 5.125 inch Textron Lycoming
>cylinders. This new
>
>assembly incorporates a heavy wall piston pin and two piloted plugs that are
>press-fitted into the inside
>
>diameter of the piston pin during manufacturing. Superior believes that the
>use of the SL13444-1
>
>piston pin assembly will provide greater engine reliability and durability
>because it greatly reduces the
>
>possibility of the plugs spinning in the piston pin.
>
>
>
>Jim
>
>
>
>
>

[[email protected][_1_]]

On Fri, 17 Aug 2007 23:59:42 -0000, "Robert M. Gary"
> wrote:


>The shop is recommending pulling all cylinders and doing a top. Does
>one cylinder having an issue with pin plugs mean others much (the IA
>says so, I'm not sure). I'm thinking I just want to replace this
>cylinder and then fly it. The oil analysis will show if there is
>another plug wearing.

One cylinder having pin plugs issues really doesn't mean a thing with
regard to pin plugs in the other cylinders. However @1000 hrs, it's
very likely that the e-valve guides in all the cylinders are at or
beyond serviceable limits.

>> Am curious what the OP or his tech found that requires cylinder
>> replacement.
>
>The IA said the cylinder was "2 one thousands" out of spec. Actually
>one of the reasons we choose this cylinder to pull ( from the oil
>analysis we knew we had to pull one of them do to progressively higher
>AL counts), was that the cross hatching was gone on #1 (this is recent
>because we boroscoped it at annual and didn't see this).
>This engine has 1000 SFNEW in 1998 so I was not expecting to have to
>replace cylinders. The IA did say that the bottom looks like a new
>engine, no sign of any problems down there (we change the oil about
>every 30 hours).
>Anyway, the IA is recommending a full top and I'm not sure that is the
>way to go.
>
>-Robert

A lot if it depends on the installation, as in how much stuff has to
get yanked off to get at the "one" cylinder.

Theshop labor cost for one should not be 1/2 of the labor cost to do
2, or 1/4 of the labor cost for 4. R/R'ing the cylinders is the easy
part. Getting all the other stuff out of the way and back on is what
takes the time...

I would definitely have the two on that side of the engine sent out
for " inspection and repair as needed". If the one that you have off
already needs to go to an oversized piston, then it's twin on the
other side should be punched out also. If you are just going to bolt
on a new one, that is not an issue.

Been a few years since I shopped for cylinders/repairs. A set of
guides, and e-valve and a ring set/hone job used to be relatively
inexpensive. If you have to purchase a piston and have the cylinder
bored oversize, you might be getting to where a new replacement is
more economical.

TC

[Denny]

I have taken the opposite tack... On a 1500 hour 0-320 that is burning
a quart every 2.7 hours I have purchased 4 factory new Lycoming
cylinder kits... Come annual time (January, when the flying is bad up
here) we will pull the old cylinders and inspect the cam and pull one
rod bearing to check for wear... If all looks OK then we will just
replace the cylinders and call it good for another 1000 hours, or
so... If any of the bottom components look bad then we will overhaul
the bottom...

denny