sticky valve or

Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up for
first time in morning but can't describe the sound and says it lasts only as
long as a finger snap.

Wants me to add Marvel Mystery oil. I use Aeroshell 100 (50 weight) and
change it every 25 hours.

I can't detect any roughness upon initial start around 900-1000 rpm in front
of my hanger nor during the taxi a couple of minutes to a runup spot. On
throttling up to 1500 for the mag check, I notice a slight hesitation around
11-1200 rpm that goes away quickly and thought was just from the low speed
taxi.

Since I had to put a rental down about 7 years ago for a valve problem (per
the FBO), there is a little "pucker" factor regarding this conversation G.

Light Plane Maintenance book references "hand proping before first start of
day to find 'flat' cylinder". Not sure I can identify a rapid falloff in
turning resistance (books definition).

Concern doesn't seem to get to the point where the "cold cylinder" test is
applicable as doesn't last long (his finger snap).

Am I chasing nothing or what is a valid approach?

Thanks, Dick

Try the MARVEL!! We've been using it (dad & I) for 30 some years mixed
in with the gas but I now think I will also use some in the oil). The
first time I didn't use it (along with 100LL on a cross country trip) I
stuck a valve with my A-65. Ran Marvel after the event, but was unable
to unstick it. Decided to pull all cylinders and have the 100 Octane
valves installed. So Marvel at something like $10/gallon, or $2000 to
have the cylinders re-worked. I could buy lots of Marvel for $2000...

Scott


Dick wrote:
Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up for
first time in morning but can't describe the sound and says it lasts only as
long as a finger snap.

Wants me to add Marvel Mystery oil. I use Aeroshell 100 (50 weight) and
change it every 25 hours.

I can't detect any roughness upon initial start around 900-1000 rpm in front
of my hanger nor during the taxi a couple of minutes to a runup spot. On
throttling up to 1500 for the mag check, I notice a slight hesitation around
11-1200 rpm that goes away quickly and thought was just from the low speed
taxi.

Since I had to put a rental down about 7 years ago for a valve problem (per
the FBO), there is a little "pucker" factor regarding this conversation G.

Light Plane Maintenance book references "hand proping before first start of
day to find 'flat' cylinder". Not sure I can identify a rapid falloff in
turning resistance (books definition).

Concern doesn't seem to get to the point where the "cold cylinder" test is
applicable as doesn't last long (his finger snap).

Am I chasing nothing or what is a valid approach?

Thanks, Dick

Scott wrote:
Try the MARVEL!! We've been using it (dad & I) for 30 some years
mixed
in with the gas but I now think I will also use some in the oil).
The
first time I didn't use it (along with 100LL on a cross country trip)
I
stuck a valve with my A-65. Ran Marvel after the event, but was
unable
to unstick it. Decided to pull all cylinders and have the 100 Octane

valves installed. So Marvel at something like $10/gallon, or $2000
to
have the cylinders re-worked. I could buy lots of Marvel for
$2000...

Scott


Dick wrote:
Old WW2 mechanic says he hears a sticky valve on my C-85 when I
fire up for
first time in morning but can't describe the sound and says it
lasts only as
long as a finger snap.

Wants me to add Marvel Mystery oil. I use Aeroshell 100 (50 weight)
and
change it every 25 hours.

I can't detect any roughness upon initial start around 900-1000 rpm
in front
of my hanger nor during the taxi a couple of minutes to a runup
spot. On
throttling up to 1500 for the mag check, I notice a slight
hesitation around
11-1200 rpm that goes away quickly and thought was just from the
low speed
taxi.

Since I had to put a rental down about 7 years ago for a valve
problem (per
the FBO), there is a little "pucker" factor regarding this
conversation G.

Light Plane Maintenance book references "hand proping before first
start of
day to find 'flat' cylinder". Not sure I can identify a rapid
falloff in
turning resistance (books definition).

Concern doesn't seem to get to the point where the "cold cylinder"
test is
applicable as doesn't last long (his finger snap).

Am I chasing nothing or what is a valid approach?

Thanks, Dick



************************************************** ********************************

I have used MMO in my vehicles and tractors and all other internal
combustion equipment for 50+ years and depend on it to help prolong the
life. Will in plane engines also.
Good luck.

Bob Olds RV-4
Charleston,Arkansas


************************************************** *******************************

On Sun, 22 May 2005 11:54:45 GMT, "Dick" wrote:

Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up for
first time in morning but can't describe the sound and says it lasts only as
long as a finger snap.

snip

Am I chasing nothing or what is a valid approach?

Thanks, Dick


get someone else to start your aircraft and stand beside him
listening. obviously he thinks he can hear something.
probably a clack clack clack sound which quickly vanishes as the valve
frees up and goes back to tolerances with the rocker.

just a thought.
Stealth Pilot
Australia.

good thought. Another I heard is to pull prop thru all 4 cylinders and feel
for "flat" cylinder.
"Stealth Pilot" wrote in message
...
On Sun, 22 May 2005 11:54:45 GMT, "Dick" wrote:

Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up
for
first time in morning but can't describe the sound and says it lasts only
as
long as a finger snap.

snip

Am I chasing nothing or what is a valid approach?

Thanks, Dick


get someone else to start your aircraft and stand beside him
listening. obviously he thinks he can hear something.
probably a clack clack clack sound which quickly vanishes as the valve
frees up and goes back to tolerances with the rocker.

just a thought.
Stealth Pilot
Australia.

And if you're REALLY (un)lucky (like I was), you might hear air rushing
past a stuck exhaust valve and hear the hiss out the exhaust pipe when
pulling it through. Then you'd have it narrowed down to 2 cylinders...

Scott



Dick wrote:

good thought. Another I heard is to pull prop thru all 4 cylinders and feel
for "flat" cylinder.
"Stealth Pilot" wrote in message
...

On Sun, 22 May 2005 11:54:45 GMT, "Dick" wrote:


Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up
for
first time in morning but can't describe the sound and says it lasts only
as
long as a finger snap.


snip

Am I chasing nothing or what is a valid approach?

Thanks, Dick


get someone else to start your aircraft and stand beside him
listening. obviously he thinks he can hear something.
probably a clack clack clack sound which quickly vanishes as the valve
frees up and goes back to tolerances with the rocker.

just a thought.
Stealth Pilot
Australia.

If following the firing order it is easy to know what cylinder it is.

But I got the feeling it can be the hydraulic lifter that is slow to fill up
after engine start, it usually make a ticking sound that quit after a few
seconds.

pull the prop slow and then fast and listen from the exhausts (or carb) and
you know where to start looking.

Jan
www.jcpropellerdesign.com

"Scott" skrev i meddelandet
...
And if you're REALLY (un)lucky (like I was), you might hear air rushing
past a stuck exhaust valve and hear the hiss out the exhaust pipe when
pulling it through. Then you'd have it narrowed down to 2 cylinders...

Scott



Dick wrote:

good thought. Another I heard is to pull prop thru all 4 cylinders and
feel
for "flat" cylinder.
"Stealth Pilot" wrote in message
...

On Sun, 22 May 2005 11:54:45 GMT, "Dick" wrote:


Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up
for
first time in morning but can't describe the sound and says it lasts
only
as
long as a finger snap.


snip

Am I chasing nothing or what is a valid approach?

Thanks, Dick


get someone else to start your aircraft and stand beside him
listening. obviously he thinks he can hear something.
probably a clack clack clack sound which quickly vanishes as the valve
frees up and goes back to tolerances with the rocker.

just a thought.
Stealth Pilot
Australia.

I would do a wobble test. If you do have a slight stick to the valve it
will get worse and at some point could cause in flight problems. A
wobble test should set your mind at ease.

Dick,

The hesitation at 1100-1200 rpms in a C-85 is normal. I have it on mine (275
smh with 0-200 conversion stc) as do most of my Luscombe brethren with the
C-85.

I recently had an exhaust valve to stick in flight. It was interesting to
say the least, and in reaction to that experience I would like to pursue a
glider rating ;-).

My valve in my 275 hour ECI cylinder was stuck but good. My engine guy
reamed it out a little as he thought the clearance was a little tight. MMO
is now part of my regular maintenance routine.


Deb

--
1946 Luscombe 8A (His)
1948 Luscombe 8E (Hers)
1954 Cessna 195B, restoring (Ours)
Jasper, Ga. (JZP)

"Dick" wrote in message
...
Old WW2 mechanic says he hears a sticky valve on my C-85 when I fire up
for first time in morning but can't describe the sound and says it lasts
only as long as a finger snap.

Wants me to add Marvel Mystery oil. I use Aeroshell 100 (50 weight) and
change it every 25 hours.

I can't detect any roughness upon initial start around 900-1000 rpm in
front of my hanger nor during the taxi a couple of minutes to a runup
spot. On throttling up to 1500 for the mag check, I notice a slight
hesitation around 11-1200 rpm that goes away quickly and thought was just
from the low speed taxi.

Since I had to put a rental down about 7 years ago for a valve problem
(per the FBO), there is a little "pucker" factor regarding this
conversation G.

Light Plane Maintenance book references "hand proping before first start
of day to find 'flat' cylinder". Not sure I can identify a rapid falloff
in turning resistance (books definition).

Concern doesn't seem to get to the point where the "cold cylinder" test is
applicable as doesn't last long (his finger snap).

Am I chasing nothing or what is a valid approach?

Thanks, Dick

Deborah McFarland wrote:
Dick,

The hesitation at 1100-1200 rpms in a C-85 is normal. I have it on
mine (275
smh with 0-200 conversion stc) as do most of my Luscombe brethren
with the
C-85.

This is fairly common on a lot of carbureted engines. It usually
occurs at the point where the carb is shifting from the idle circuit to
the main jet.

John Galban=====N4BQ (PA28-180)