How to Remove Piston from Cylinder

Does anyone have a technique to get the piston out? Preferably while doing
the least amount of damage. (So no explosives, please!)

Take an old spark plug and break out the ceramic center, then thread the
steel body for a zerk fitting. *Be sure both valves are closed, hook up
grease gun and start pumping; you might be able to build enough pressure
(grease guns are cabable of several thousand psi) to break the ring and
force the piston out or even push the liner out of the one-piece
cylinder/head.

Adding to that idea heat the whole thing in an oven and then pack the
bore with ice upon removal. Remove the piston and the steel liner as
one assembly. Then renew as one would normally with a Franklin
cylinder/head combo ????

Never had this problem, and never tried this fix .............. Pure
speculation on my part.
================
Leon McAtee
Will remember not to do the same with my Franklin :-)

On Oct 1, 11:29*am, "Paul Dow (Remove Caps in mail address)"
wrote:

Does anyone have a technique to get the piston out? Preferably while
doing the least amount of damage. (So no explosives, please!)
-------------------------------------------------------------------------------------------------

I don't see any easy-out for this one.

I assume you're willing to sacrifice the piston in order to salvage
the cylinder, in which case you might try soaking the piston with
liquid nitrogen or other cryogenic that should allow you to shatter
the piston along the ring-groove.

Depending on how much of the upper portion of the piston is obscured
by the wrist pin, you might consider fabricating a fixture of some
sort bearing a number of high-gauss rare-earth magnets, the idea being
to cause the ring to be drawn back into its groove whilst the assembly
is under tension.

In a similar vein, the suggestion about using the piston to remove the
cylinder liner would appear to have merit. You should be able to rig
the assembly so as to create considerable tension between the cylinder
and the piston. The manual should give you some idea as to the
required temperature difference, which would be obtained by raising
the whole assembly to a given temperature then hitting the piston AND
liner with liquid nitrogen.

-R.S.Hoover

wrote:
On Oct 1, 11:29 am, "Paul Dow (Remove Caps in mail address)"
wrote:

Does anyone have a technique to get the piston out? Preferably while
doing the least amount of damage. (So no explosives, please!)
-------------------------------------------------------------------------------------------------

I don't see any easy-out for this one.

I assume you're willing to sacrifice the piston in order to salvage
the cylinder, in which case you might try soaking the piston with
liquid nitrogen or other cryogenic that should allow you to shatter
the piston along the ring-groove.

Depending on how much of the upper portion of the piston is obscured
by the wrist pin, you might consider fabricating a fixture of some
sort bearing a number of high-gauss rare-earth magnets, the idea being
to cause the ring to be drawn back into its groove whilst the assembly
is under tension.

In a similar vein, the suggestion about using the piston to remove the
cylinder liner would appear to have merit. You should be able to rig
the assembly so as to create considerable tension between the cylinder
and the piston. The manual should give you some idea as to the
required temperature difference, which would be obtained by raising
the whole assembly to a given temperature then hitting the piston AND
liner with liquid nitrogen.

-R.S.Hoover


This idea is the best so far--I would recommend hanging the assy. by the
rod, and attaching heavy weight to cyl head.. Then apply heat to barrel
of Cylinder.

I keep some old Coleman thermos bottle liners (vacuum bottles) then go
out to propane storage tank, crack the liquid line ,and after the valve
& line has chilled, introduce liquid into vacuum bottle...Careful--
the temp is -42°C-(-62°F)AND of course the vapor is highly flammable,and
1.5 times as dense as air--so it settles in low places.

Extinguish all fires & pilot lights---WEAR GOGGLES---The liquid will
boil violently upon contact with the hot metal---You have to do this
when you live 50 miles from Mr.Linde--& he might not have any liquid N2
that day anyhow..
Jerry

On Oct 2, 9:41*am, Jerry Wass wrote:
wrote:
On Oct 1, 11:29 am, "Paul Dow (Remove Caps in mail address)"
wrote:

Does anyone have a technique to get the piston out? Preferably while
doing the least amount of damage. (So no explosives, please!)
---------------------------------------------------------------------------*----------------------

I don't see any easy-out for this one.

I assume you're willing to sacrifice the piston in order to salvage
the cylinder, in which case you might try soaking the piston with
liquid nitrogen or other cryogenic that should allow you to shatter
the piston along the ring-groove.

Depending on how much of the upper portion of the piston is obscured
by the wrist pin, you might consider fabricating a fixture of some
sort bearing a number of high-gauss rare-earth magnets, the idea being
to cause the ring to be drawn back into its groove whilst the assembly
is under tension.

In a similar vein, the suggestion about using the piston to remove the
cylinder liner would appear to have merit. *You should be able to rig
the assembly so as to create considerable tension between the cylinder
and the piston. *The manual should give you some idea as to the
required temperature difference, which would be obtained by raising
the whole assembly to a given temperature then hitting the piston AND
liner with liquid nitrogen.

-R.S.Hoover

This idea is the best so far--I would recommend hanging the assy. by the
rod, and attaching heavy weight to cyl head.. Then apply heat to barrel
of Cylinder.

I keep some old Coleman thermos bottle liners (vacuum bottles) then go
out to propane storage tank, crack the liquid line ,and after the valve
& line has chilled, introduce *liquid into vacuum bottle...Careful--
the temp is -42°C-(-62°F)AND of course the vapor is highly flammable,and
1.5 times as dense as air--so it settles in low places.

Extinguish all fires & pilot lights---WEAR GOGGLES---The liquid will
boil violently upon contact with the hot metal---You have to do this
when you live 50 miles from Mr.Linde--& he might not have any liquid N2
that day anyhow..
Jerry- Hide quoted text -

- Show quoted text -
Is there any reason why the pistons head can’t be drilled out and an
insert fabricated to slip inside it through the top for use as a
puller? You can use a chemical fire extinguisher to super cool the
cylinder head for shrinkage and then follow up with a series of sharp
pulls to extract the piston. If the piston shatters then remove it,
or its top pulls loose than fabricated another top insert to friction
fit inside the piston walls and try the whole chill/pull process
again. Of course this is just my .02 worth folks along with the
admonition that I’m more of a parts changer than mechanic.
Joe Stevenson

Is anyone in the chapter a surgeon or does anyone know one personally? I
have a surgeon friend who's an expert in performing abdominal surgery
through a tiny incision. He could remove your appendix though your belly
button. I think someone like him would find it possible to work through the
spark plug holes and squeeze the ring enough to let it slip past the top of
the sleeve.

"Paul Dow (Remove Caps in mail address)" wrote in
message ...
A member of our EAA chapter has a cylinder from a Franklin 150 engine (off
the engine.) The piston was pushed too far up and the top ring sprung out
so it now overlaps the cylinder sleeve which locks the piston in place.

Does anyone have a technique to get the piston out? Preferably while doing
the least amount of damage. (So no explosives, please!)

Thanks,
Paul

Jon Woellhaf wrote:
Is anyone in the chapter a surgeon or does anyone know one personally? I
have a surgeon friend who's an expert in performing abdominal surgery
through a tiny incision. He could remove your appendix though your belly
button. I think someone like him would find it possible to work through the
spark plug holes and squeeze the ring enough to let it slip past the top of
the sleeve.


I think you are smoking something strong if you think a surgeon is
going to use instruments intended for use in the body in a plane - and
as a general rule, the equipment/instrument is usually owned by
hospitals, not by the docs..

I like the grease gun idea the best.. any 'noncompressible' media will
do - water, grease, oil.. just not AIR..

OR.. fill the head with water, valves closed, spark plug hole sealed,
and freeze it. Water expands a little as it freezes.. it will overcome
any shear resistance the rings have.

I didn't say anything about using surgical instruments. I don't smoke, but I
have been painting a lot today. g

"Dave S" wrote in message
...
Jon Woellhaf wrote:
Is anyone in the chapter a surgeon or does anyone know one personally? I
have a surgeon friend who's an expert in performing abdominal surgery
through a tiny incision. He could remove your appendix though your belly
button. I think someone like him would find it possible to work through
the spark plug holes and squeeze the ring enough to let it slip past the
top of the sleeve.


I think you are smoking something strong if you think a surgeon is going
to use instruments intended for use in the body in a plane - and as a
general rule, the equipment/instrument is usually owned by hospitals, not
by the docs..

I like the grease gun idea the best.. any 'noncompressible' media will
do - water, grease, oil.. just not AIR..

OR.. fill the head with water, valves closed, spark plug hole sealed, and
freeze it. Water expands a little as it freezes.. it will overcome any
shear resistance the rings have.

Dave S wrote:
Jon Woellhaf wrote:
Is anyone in the chapter a surgeon or does anyone know one personally?
I have a surgeon friend who's an expert in performing abdominal
surgery through a tiny incision. He could remove your appendix though
your belly button. I think someone like him would find it possible to
work through the spark plug holes and squeeze the ring enough to let
it slip past the top of the sleeve.


I think you are smoking something strong if you think a surgeon is
going to use instruments intended for use in the body in a plane - and
as a general rule, the equipment/instrument is usually owned by
hospitals, not by the docs..

I like the grease gun idea the best.. any 'noncompressible' media will
do - water, grease, oil.. just not AIR..

OR.. fill the head with water, valves closed, spark plug hole sealed,
and freeze it. Water expands a little as it freezes.. it will overcome
any shear resistance the rings have.

The ring may not have expanded all the way round, in that case, you
might coax the piston out using a set of long feeler gauges slipped
between the piston and wall and twisting the piston gently. I have a
set of feeler gauges made for piston work that are a little over twelve
inches long. Not surgical tools, but could get the job done. My
Franklin Manual(very dated) shows the max wear cold clearance to be .036
at the piston top, so it just might be doable.

You could also fabricate a tool from music wire by annealing it,
flattening the end very thin with hammer and anvil (small) and then
rehardening it. Working through the plug holes with several tools and a
lot of patience you might be able to coax it back in.

In big transformers we have an effect called magnetostriction (the cause
of the hum you hear) I was curious if it would have an effect on a
piston ring, so I tried it out with a small piston ring from a weedeater
motor in my growler. No effect. I couldn't find my degaussing coil
(which might produce a more useful field), so could not try that, but
suspect that if it did have an effect it would be to open the gap and
actually spread the ring. The ring had a lot more tension than I
thought. I grabbed an old automotive ring (no idea what it is off of --
I save everything) and am guessing that it would take north of ten
pounds of pressure to compress it, which calls for a pretty strong
magnetic field when it is expected to perform over a considerable gap.

There are also several acids that will attack steel and not aluminum. I
have used that dodge many years ago to remove a busted tap from an
aluminum part that I had a lot of time invested in. I used plain
battery acid that time, but I think I recall that nitric acid could work
better. This would likely attack the valve seats and liner, but would
not harm the head or piston. You would want to degrease everything
before trying the acid.

As far as heating it up and pulling the liner, my (very dated) Franklin
manual shows the liner and valve guides are installed with the jug
heated to between 625-650 degrees F. They list this same temperature
for replacement of the guides, but there is no guidance on removing the
liner. It does show the liner is held in place by one or more
(depending on the model) locking pins at the base (flange) of the jug.
The locking pin is inserted in and held in place by two socket head
screws placed in the hole one after another. The cylinder is finish
ground and honed after the pin(s)are installed, so once you pull the
liner, you are sending it out to be reworked, in which case you might as
well let them deal with the whole problem.

Charles

Charles Vincent wrote:

There are also several acids that will attack steel and not aluminum. I
have used that dodge many years ago to remove a busted tap from an
aluminum part that I had a lot of time invested in. I used plain
battery acid that time, but I think I recall that nitric acid could work
better. This would likely attack the valve seats and liner, but would
not harm the head or piston. You would want to degrease everything
before trying the acid.


On reflection, forget I said that. To much risk that the acid would
have some long term effect and I simply don't know enough about it to
recommend it for an aircraft part.

Charles

Hi Paul,
do you know this document, mainly the drawing around page 2-40 or at 2-35?
http://www.franklin.ioi.pl/dokumenty...ts_Catalog.pdf

http://www.franklin.ioi.pl/dokumenty/IPC_4A235_B4.pdf

It seems the cylinder liner can be pulled if the lock pin is removed.

Much luck
Walter