Today's Message Index:
----------------------
1. 07:17 AM - Re: propeller pull through procedure (Bitterlich, Mark G CIV NAVAIR, WD)
2. 09:18 AM - Fort Myers, FL (Byron Fox)
3. 10:49 AM - Re: propeller pull through procedure (PaulW)
4. 10:56 AM - Re: propeller pull through procedure (PaulW)
5. 04:22 PM - Re: propeller pull through procedure (Joe Enzminger)
6. 06:35 PM - Re: Re: Aerobatic with CJ6A (cjpilot710@aol.com)
7. 07:25 PM - Looking for Al Demazio (rmhou@yahoo.com)
8. 08:12 PM - Re: Re: propeller pull through procedure (Todd McCutchan)
9. 08:50 PM - Re: Re: propeller pull through procedure (Dave Laird)
10. 09:30 PM - Re: Re: propeller pull through procedure (Walter Lannon)
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| Subject: | propeller pull through procedure |
I'll add one small point to what Richard said. You mentioned you have the lower
cylinder intake drain kit installed. After you pull the prop blades through
a few times and get the majority of oil out, prime it as has been previously
mentioned. Keep a very close eye on the lower cylinder drain kit exit. You
should see fuel streaming out of it, assuming you primed enough fuel in there
to begin with. If you do NOT see this fuel coming out, then you probably have
congealed (read: "thick") oil in those lines, which means you have no real
idea how much oil is behind that! This is particularly true with tail draggers
where the engine sits at a "cant", I.E. Tilted back a tad. In addition, if
these lines are free and clear of oil, it is very difficult to create a hydraulic
lock from fuel priming alone. I guess it could be done if you really tried,
but the majority of any prime will run right out the cylinder drain leaving
about the right amount in there to start... after you pull it through some more.
I will NOT crank my M-14, until I see fuel from prime coming out that drain.
Mark
-----Original Message-----
From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Richard Goode
Sent: Monday, February 17, 2014 11:43 AM
Subject: RE: Yak-List: propeller pull through procedure
--> <richard.goode@russianaeros.com>
The really is not a fixed number of blades, since there are a lot of variables,
the main ones being:
A simple point - but two or three blade prop?
Temperature - if it is very cold it will take much longer for viscous oil to leave
the engine.
Engine condition - does a lot of oil come down into the intake tubes and into the
lower cylinders? If the engine is old and worn and this is happening, clearly
you will need to turn the propeller through more revolutions than you will
a new engine with tight clearances which does not allow much oil into the intake
tubes/cylinders
The amount of oil that comes out - obviously connected with the point above, but
if any significant amount of oil comes out of the exhausts, then you need to
continue turning until it is absolutely clear.
But, turning the propeller is not "squirting more oil in"- certainly not in measurable
quantities.
Priming into the supercharger, particularly in cold weather will help to move congealed
oil. But make sure it is into "system" rather than "cylinder", or you
will get dramatically over priming, and possibly a hydraulic lock, which is just
what you are trying to avoid.
Having said that, I would suggest that 18 revolutions is more than is likely to
be needed except in the case of a worn/oily engine.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com] On Behalf Of PaulW
Sent: 17 February 2014 16:16
Subject: Yak-List: propeller pull through procedure
Hi
This probably has been covered a zillion times, but I can't find any reference
to it.
With a M14-P in a Yak, how many times do you really pull the prop through and when
do you know you have pulled it through enough?
Some say 9 times, some say till no more oil come out of the exhaust, etc.
I am pulling through 36 blades. Is that an overkill?
I have been thinking that maybe I am just pumping in more oil which I am draining
out again if done to many times.
What if you squirt a bit of fuel in with the primer just before or after the pull
through to make the oil thinner. Will that work to get the oil out or just
the opposite?
There is a drain mod installed in the bottom 3 cylinders where the oil drain out
through a tap at the bottom and of course containers underneath the exhausts.
At the moment I pull through 36 blades, do rest of pre-flight which may take another
15 minutes or more, then 3 blades, 3 primes, 3 blades, 3 primes.
Then get in, strap in, 3 primes and start.
Any comments on the number of blades to turn?
regards
Paul
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418874#418874
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Will be in Ft Myers this coming weekend, 2/22-24, reuniting with a half dozen high
school
pals. If anybody has an empty back seat, I'd love to introduce one or more of these
guys to the RPA experience.
Blitz Fox
415-307-2405
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| Subject: | Re: propeller pull through procedure |
Thank you everybody for the replies, I appreciate it. Definitely picked up new
info.
I am very wary/concerned not to get hydraulic lock as I believe from reading these
forums and listing to others that plenty of engines don't reach TBO due to
hydraulic lock.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418947#418947
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| Subject: | Re: propeller pull through procedure |
richard.goode(at)russiana wrote:
>
>
> A simple point - but two or three blade prop?
>
>
Good point, never thought about the difference :D
In this case a 2 blade original Russian prop. B530Ta-D35
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418948#418948
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| Subject: | Re: propeller pull through procedure |
After 9 years of owning a CJ and 3 years of owning a Yak-55, and having the same
questions, I think having a good understanding of the theory behind "pulling
the prop through" is important. Too many people rely on time honored and passed
down lore in deciding how to prevent hydraulic lock.
Hydraulic lock occurs when the cylinder head attempts to compress incompressible
fluid (usually oil or fuel). If the volume of fluid in the cylinder is more
than the total volume of the cylinder when the cylinder head is at full compression,
the force required to continue to move the cylinder head will increase
dramatically. If you continue to force it through, something besides the incompressible
fluid will give first (usually a connecting rod).
As you pull the prop through, each cylinder is at a slightly different phase of
the power cycle. The goal is to have each cylinder that is susceptible to a
lock (usually the lower ones), go through a complete cycle - intake, compression,
power, exhaust. For a cylinder to lock, it is usually necessary that both
the intake and exhaust valves be closed (otherwise the fluid would drain out
of the cylinder into the exhaust (and your hangar floor), or your intake (more
on this later).
In the condition where both valves are closed, you are either between the intake-compression
or the power-exhaust phase of the compression cycle. If the latter,
as you pull, the cylinder head is moving "down", or away from the top of
the cylinder, and when it reaches the bottom, the exhaust valve will open and
any fluid in the cylinder will begin to drain out the exhaust. You'll also usually
hear some air actually get sucked into the cylinder. Usually when I hear
this sucking sound its a clue to stop for a few seconds and make sure I'm upwind
of the exhaust (because oil is about to come streaming out). In this situation,
even though you may have had enough oil to generate a lock, in a short
time it will drain out and you'll be AOK to start (after completing checking
all the other cylinders). The colder it is outside, the more time you should
give it to drain.
In the former case, (intake-compression), you'll feel the lock. If you get here,
what you do next depends on your airplane.
If you don't have intake drains installed, then your only option is to pull the
spark plugs and drain the oil. The advice not to pull the prop backward applies
here because if you do, the intake valve will open and the oil will dump into
the intake. You'll be able to pull the prop through after that, but when
you start the engine there is a good chance that oil will immediately be sucked
back into the cylinder, locking at power, and trashing your engine.
If you do have intake drains installed, then pulling the prop through backward
is safe (in my opinion - although others might disagree and I'd be interested
in learning their reasons), provided you also take the time to make sure you
get oil draining out of your intake drain afterward. The technique is to go back
enough to allow the intake valve to open. Again, usually you can hear this
as a sucking sound as air is sucked into the intake valve when it opens. Once
you hear this, wait a few moments and check to see if oil starts to drain from
the intake. If you don't see oil, then it is likely you have a plug in your
intake drains and you need to pull your plugs and drains to clear them out.
However, in most cases, you'll start to see a steady stream of oil that usually
takes 10 to 15 minutes to stop. Do keep in mind that while pulling the prop
through backwards you might hit a lock on another cylinder, in which case you
should stop and pull plugs. Rare, but I suppose it could happen. Once you've
given the oil time to drain, pull the prop through normally to confirm that
you've successfully cleared the lock, and continue with your normal procedure
until you've checked all the cylinders - in other words, if you find a lock
on blade 2 and clear it, don't stop - continue to pull through to check the other
cylinders.
You can also use the primer to thin out the oil in the intake to make it drain
quicker. If you don't have intake drains, I do not recommend using the primer
to "thin out the oil" as the fuel will collect in the intake and could actually
cause a hydraulic lock by itself.
In any of these airplanes, I would HIGHLY recommend intake drains. Another condition
that can trash an engine is oil draining into a lower cylinder and out
the cylinder though an open intake valve into the intake (where it sits). You
dutifully pull the prop through (with no abnormal resistance), and start the
engine, whereby all that oil (and the prime you shot in) gets sucked in through
the intake and blocks the compression stroke, trashing your engine.
My goal in pulling the prop through is to have each cylinder go through one full
intake/compression/power/exhaust cycle. On the M14 this requires 6 crankshaft
revolutions, or 18 blades on a 3 blade prop and 12 on a two blade. I believe
it to be the same for the HS6A, but I'm not 100% sure. More is just making
your arms tired. If I get a lot of oil out of my first pull-through session,
I might do another after letting the airplane sit a few minutes just to make
sure everything is clear.
Another note about pulling though - remember that this might be the most dangerous
thing you do the entire flight. Make triple sure mags and shower of sparks
are off, and make sure the aircraft is chocked (especially if you do this inside
of the hangar). Keep your limbs clear of the plane of rotation and always
assume that you might inadvertently start the engine. Always. Lots of war
stories about what happens if you don't.
Joe Enzminger
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418964#418964
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| Subject: | Re: Aerobatic with CJ6A |
Never tried inverted spin personally. Some years ago just before OSH, we
had get together at MTW. We asked one of the Russian acro champs to come
and be available to give acro instruction to the Yak 52 guys. He went up
with Keith Harbor (If I'm remembering right) and they did some inverted spin
in Keith's CJ. Since it has no inverted oil system of course so the HS6A
engine in Keith airplane, dumped its oil though the breather. I didn't get
to discuss how well the CJ did them, but I don't think it would be "stellar".
I'm not sure if having a M-14p in a CJ will make a flat spin easier to
enter. The M-14 is heaver than the Chinese HS6A by about 70lbs ( That number
sticks in my mind) so until you adjust the ballast, it would make the
airplane more nose heavy. Plus that weight's inertia has to be over come to get
the airplane rotating. But I've never tried flat spins in a HS6a powered
CJ.
The first time was very interesting! I had done my little routine for a
little fly-in at our airpark. In my routine I push the power to 2400 rpm
and 32" to 34" mp and leave it there though out. After landing and bowing to
the adulation's of the crowd, one gentleman wanted to go up and ride though
the routine with me. I needed fuel anyway, so he hop in and I flew to
the local airport and refueled. ON the way back to the airpark, he asked
about spins, and I told him I'd demo one at the end of the routine. I climb
to 4,000' set up my power and flew the routine. The end of the was a loop.
I was talking to him as I did each maneuver. So - - "I'll now show you a
2 turn spin." I continued to pull the nose up to 40 deg or so and at the
stall brake, I push hard right rudder, and pulled the stick straight into my
stomach. I NEVER REDUCED THE THROTTLE. The airplane broke into what I
thought was very normal "stable" spin, with no pitch changing through the
rotations. At the end of the second turn, I released the pressure on the
stick, expecting it to move forward and recover. The stick DID NOT MOVE. It
was a half a turn before I realized something was not right. At point I
pushed forward on the stick, and was surprised at the amount of force required
- 3 pounds. I terminated the flight thinking maybe something was
mechanically wrong. After discussing it with some real pros, I discovered I had
inadvertently enter a flat spin by leaving the power on at stall brake. It
does get your attention.
But note my airplane was at its most rearward CG. I had full tanks (55
gals), chutes, and a more than standard weight passenger in back.
Jim "Pappy" Goolsby
In a message dated 2/17/2014 9:43:38 P.M. Eastern Standard Time,
cetopfed@gmail.com writes:
--> Yak-List message posted by: "keithmckinley" <cetopfed@gmail.com>
Pappy,
I would imagine that a aft loaded CJ with an M-14 might be coaxed into a
flat spin. Must be interesting!
My reference was for a stock CJ since it looked like that's what the
original poster has.
Have you ever tried to spin it inverted?
Keith
--------
Keith McKinley
700HS
X26 Sebastian, FL
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418919#418919
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| Subject: | Looking for Al Demazio |
I am helping my local FBO to locate Al Demazio who owns a Yak-52 N352YK. He left
a clipboard and the FBO owner wants to return it to him.
If you kbow Al, please ask him to email me so I can put him in touch with the FBO
owner.
Robin Hou
rmhou@yahoo.com
Sent from Yahoo Mail on Android
Message 8
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| Subject: | Re: propeller pull through procedure |
Todd McCutchan
T-34A & Yak-50
Cell: (260) 402-1740
E-mail: todd@fastaircraft.com
www.fastaircraft.com
> On Feb 18, 2014, at 4:21 PM, "Joe Enzminger" <panchoandlefty2002@yahoo.com
> wrote:
>
com>
>
> After 9 years of owning a CJ and 3 years of owning a Yak-55, and having th
e same questions, I think having a good understanding of the theory behind "
pulling the prop through" is important. Too many people rely on time honore
d and passed down lore in deciding how to prevent hydraulic lock.
>
> Hydraulic lock occurs when the cylinder head attempts to compress incompre
ssible fluid (usually oil or fuel). If the volume of fluid in the cylinder i
s more than the total volume of the cylinder when the cylinder head is at fu
ll compression, the force required to continue to move the cylinder head wil
l increase dramatically. If you continue to force it through, something bes
ides the incompressible fluid will give first (usually a connecting rod).
>
> As you pull the prop through, each cylinder is at a slightly different pha
se of the power cycle. The goal is to have each cylinder that is susceptibl
e to a lock (usually the lower ones), go through a complete cycle - intake, c
ompression, power, exhaust. For a cylinder to lock, it is usually necessary
that both the intake and exhaust valves be closed (otherwise the fluid woul
d drain out of the cylinder into the exhaust (and your hangar floor), or you
r intake (more on this later).
>
> In the condition where both valves are closed, you are either between the i
ntake-compression or the power-exhaust phase of the compression cycle. If t
he latter, as you pull, the cylinder head is moving "down", or away from the
top of the cylinder, and when it reaches the bottom, the exhaust valve will
open and any fluid in the cylinder will begin to drain out the exhaust. Yo
u'll also usually hear some air actually get sucked into the cylinder. Usua
lly when I hear this sucking sound its a clue to stop for a few seconds and m
ake sure I'm upwind of the exhaust (because oil is about to come streaming o
ut). In this situation, even though you may have had enough oil to generate
a lock, in a short time it will drain out and you'll be AOK to start (after
completing checking all the other cylinders). The colder it is outside, th
e more time you should give it to drain.
>
> In the former case, (intake-compression), you'll feel the lock. If you ge
t here, what you do next depends on your airplane.
>
> If you don't have intake drains installed, then your only option is to pul
l the spark plugs and drain the oil. The advice not to pull the prop backwa
rd applies here because if you do, the intake valve will open and the oil wi
ll dump into the intake. You'll be able to pull the prop through after that
, but when you start the engine there is a good chance that oil will immedia
tely be sucked back into the cylinder, locking at power, and trashing your e
ngine.
>
> If you do have intake drains installed, then pulling the prop through back
ward is safe (in my opinion - although others might disagree and I'd be int
erested in learning their reasons), provided you also take the time to make s
ure you get oil draining out of your intake drain afterward. The technique i
s to go back enough to allow the intake valve to open. Again, usually you c
an hear this as a sucking sound as air is sucked into the intake valve when i
t opens. Once you hear this, wait a few moments and check to see if oil sta
rts to drain from the intake. If you don't see oil, then it is likely you h
ave a plug in your intake drains and you need to pull your plugs and drains t
o clear them out. However, in most cases, you'll start to see a steady stre
am of oil that usually takes 10 to 15 minutes to stop. Do keep in mind that
while pulling the prop through backwards you might hit a lock on another cy
linder, in which case you should stop and pull plugs. Rare, but I suppose !
> it could happen. Once you've given the oil time to drain, pull the prop t
hrough normally to confirm that you've successfully cleared the lock, and co
ntinue with your normal procedure until you've checked all the cylinders - i
n other words, if you find a lock on blade 2 and clear it, don't stop - cont
inue to pull through to check the other cylinders.
>
> You can also use the primer to thin out the oil in the intake to make it d
rain quicker. If you don't have intake drains, I do not recommend using the
primer to "thin out the oil" as the fuel will collect in the intake and cou
ld actually cause a hydraulic lock by itself.
>
> In any of these airplanes, I would HIGHLY recommend intake drains. Anothe
r condition that can trash an engine is oil draining into a lower cylinder a
nd out the cylinder though an open intake valve into the intake (where it si
ts). You dutifully pull the prop through (with no abnormal resistance), and
start the engine, whereby all that oil (and the prime you shot in) gets suc
ked in through the intake and blocks the compression stroke, trashing your e
ngine.
>
> My goal in pulling the prop through is to have each cylinder go through on
e full intake/compression/power/exhaust cycle. On the M14 this requires 6 c
rankshaft revolutions, or 18 blades on a 3 blade prop and 12 on a two blade.
I believe it to be the same for the HS6A, but I'm not 100% sure. More is j
ust making your arms tired. If I get a lot of oil out of my first pull-thro
ugh session, I might do another after letting the airplane sit a few minutes
just to make sure everything is clear.
>
> Another note about pulling though - remember that this might be the most d
angerous thing you do the entire flight. Make triple sure mags and shower o
f sparks are off, and make sure the aircraft is chocked (especially if you d
o this inside of the hangar). Keep your limbs clear of the plane of rotatio
n and always assume that you might inadvertently start the engine. Always.
Lots of war stories about what happens if you don't.
>
> Joe Enzminger
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=418964#418964
>
>
>
>
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
>
>
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| Subject: | Re: propeller pull through procedure |
Great post Joe!
Really thought out and well written!
Thank you for helping to make this list so great for all of us!
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| Subject: | Re: propeller pull through procedure |
Really excellent write up Joe.
I think you have covered all the bases and I couldn't agree more,
particularly with your advice to sit back and let it drain when you do get
some oil.
The actual minimum CRANKSHAFT rotation necessary to cycle all cylinders is
4.5 for all 9 cyl. radials. That is 9 blades for a direct drive engine.
Minimum for the M14P is 6 blades ( 4.5 X 0.658 X 2) and for the Huosai 7
blades (4.5 X 0.787 X 2).
Walt
-----Original Message-----
From: Joe Enzminger
Sent: Tuesday, February 18, 2014 4:21 PM
Subject: Yak-List: Re: propeller pull through procedure
<panchoandlefty2002@yahoo.com>
After 9 years of owning a CJ and 3 years of owning a Yak-55, and having the
same questions, I think having a good understanding of the theory behind
"pulling the prop through" is important. Too many people rely on time
honored and passed down lore in deciding how to prevent hydraulic lock.
Hydraulic lock occurs when the cylinder head attempts to compress
incompressible fluid (usually oil or fuel). If the volume of fluid in the
cylinder is more than the total volume of the cylinder when the cylinder
head is at full compression, the force required to continue to move the
cylinder head will increase dramatically. If you continue to force it
through, something besides the incompressible fluid will give first (usually
a connecting rod).
As you pull the prop through, each cylinder is at a slightly different phase
of the power cycle. The goal is to have each cylinder that is susceptible
to a lock (usually the lower ones), go through a complete cycle - intake,
compression, power, exhaust. For a cylinder to lock, it is usually
necessary that both the intake and exhaust valves be closed (otherwise the
fluid would drain out of the cylinder into the exhaust (and your hangar
floor), or your intake (more on this later).
In the condition where both valves are closed, you are either between the
intake-compression or the power-exhaust phase of the compression cycle. If
the latter, as you pull, the cylinder head is moving "down", or away from
the top of the cylinder, and when it reaches the bottom, the exhaust valve
will open and any fluid in the cylinder will begin to drain out the exhaust.
You'll also usually hear some air actually get sucked into the cylinder.
Usually when I hear this sucking sound its a clue to stop for a few seconds
and make sure I'm upwind of the exhaust (because oil is about to come
streaming out). In this situation, even though you may have had enough oil
to generate a lock, in a short time it will drain out and you'll be AOK to
start (after completing checking all the other cylinders). The colder it is
outside, the more time you should give it to drain.
In the former case, (intake-compression), you'll feel the lock. If you get
here, what you do next depends on your airplane.
If you don't have intake drains installed, then your only option is to pull
the spark plugs and drain the oil. The advice not to pull the prop backward
applies here because if you do, the intake valve will open and the oil will
dump into the intake. You'll be able to pull the prop through after that,
but when you start the engine there is a good chance that oil will
immediately be sucked back into the cylinder, locking at power, and trashing
your engine.
If you do have intake drains installed, then pulling the prop through
backward is safe (in my opinion - although others might disagree and I'd be
interested in learning their reasons), provided you also take the time to
make sure you get oil draining out of your intake drain afterward. The
technique is to go back enough to allow the intake valve to open. Again,
usually you can hear this as a sucking sound as air is sucked into the
intake valve when it opens. Once you hear this, wait a few moments and
check to see if oil starts to drain from the intake. If you don't see oil,
then it is likely you have a plug in your intake drains and you need to pull
your plugs and drains to clear them out. However, in most cases, you'll
start to see a steady stream of oil that usually takes 10 to 15 minutes to
stop. Do keep in mind that while pulling the prop through backwards you
might hit a lock on another cylinder, in which case you should stop and pull
plugs. Rare, but I suppose !
it could happen. Once you've given the oil time to drain, pull the prop
through normally to confirm that you've successfully cleared the lock, and
continue with your normal procedure until you've checked all the cylinders -
in other words, if you find a lock on blade 2 and clear it, don't stop -
continue to pull through to check the other cylinders.
You can also use the primer to thin out the oil in the intake to make it
drain quicker. If you don't have intake drains, I do not recommend using
the primer to "thin out the oil" as the fuel will collect in the intake and
could actually cause a hydraulic lock by itself.
In any of these airplanes, I would HIGHLY recommend intake drains. Another
condition that can trash an engine is oil draining into a lower cylinder and
out the cylinder though an open intake valve into the intake (where it
sits). You dutifully pull the prop through (with no abnormal resistance),
and start the engine, whereby all that oil (and the prime you shot in) gets
sucked in through the intake and blocks the compression stroke, trashing
your engine.
My goal in pulling the prop through is to have each cylinder go through one
full intake/compression/power/exhaust cycle. On the M14 this requires 6
crankshaft revolutions, or 18 blades on a 3 blade prop and 12 on a two
blade. I believe it to be the same for the HS6A, but I'm not 100% sure.
More is just making your arms tired. If I get a lot of oil out of my first
pull-through session, I might do another after letting the airplane sit a
few minutes just to make sure everything is clear.
Another note about pulling though - remember that this might be the most
dangerous thing you do the entire flight. Make triple sure mags and shower
of sparks are off, and make sure the aircraft is chocked (especially if you
do this inside of the hangar). Keep your limbs clear of the plane of
rotation and always assume that you might inadvertently start the engine.
Always. Lots of war stories about what happens if you don't.
Joe Enzminger
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