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.

Could you describe the "wobble test"? Not familiar with the term.
Thans, Dick
"Robert M. Gary" wrote in message
oups.com...
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.

On Tue, 24 May 2005 11:03:11 GMT, "Dick" wrote:

Could you describe the "wobble test"? Not familiar with the term.
Thans, Dick
"Robert M. Gary" wrote in message
roups.com...
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.

It literally means removing the rocker arm and valve spring, grabbing
the valve stem and seeing if you can wobble it back and forth. If you
can it means the valve guide is worn.

The valve guide has to hold the valve in it's cylinder without
wobbling because if it's wobbling it isn't seating on the valve seat.
If it isn't seating on the valve seat properly, it's leaking. If it's
leaking, it's either burned or about to be burned (if we're talking
about exhaust valves).

See: http://egaa.home.mindspring.com/engine1.htm for an extremely
comprehensive look at the issue of valve guide wear in parallel valve
Lycoming engines.

Corky Scott