Today's Message Index:
----------------------
1. 03:27 AM - Re: Re: worn valve guides (Tex Mantell)
2. 03:35 AM - Re: putting things in perspective (Tex Mantell)
3. 03:47 AM - valve problem (Tex Mantell)
4. 06:33 AM - Re: Re: While Checking the Magnetos, intermittent shutdown (FLYaDIVE)
5. 06:54 AM - Re: Re: While Checking the Magnetos, intermittent shutdown (Dennis W. Wilt)
6. 10:43 AM - Re: valve problem (Kayberg@aol.com)
7. 12:27 PM - Re: valve problem (FLYaDIVE)
8. 01:14 PM - Re: valve problem (Gary Aman)
9. 01:51 PM - Re: valve problem (Tex Mantell)
10. 02:00 PM - Re: valve problem (BobsV35B@aol.com)
11. 02:19 PM - Talk About Valves (Wagner)
12. 02:28 PM - Re: valve problem (Kayberg@aol.com)
13. 02:38 PM - Re: valve problem (Naftali Horowitz)
14. 03:35 PM - Re: valve problem (FLYaDIVE)
15. 03:48 PM - Re: Talk About Valves (Martin Hone)
16. 03:53 PM - Re: valve problem (Pete Krotje)
17. 04:01 PM - Re: valve problem (Rob Turk)
18. 04:09 PM - Re: Talk About Valves (Wagner)
19. 04:28 PM - Re: Talk About Valves (Martin Hone)
20. 04:36 PM - Re: valve problem (Nick Otterback)
21. 06:44 PM - Re: valve problem (GREGSMI@aol.com)
Message 1
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| Subject: | Re: worn valve guides |
Clive,
I have another 2200 with the problem and its #2523. I plan to find the
guides local if Possible for I have the tools to do it. I hope to
contact someone to find out what spec material should be used if I have
to make them. The bronze material comes in many flavors. Also I will
have to determine the proper size for each valve when I get the heads
off. If I remember right you found that the VW golf had a similar size
guide. How did that work out? Will keep you posted and again thanks for
your reply.
Tex
----- Original Message -----
From: James, Clive R
To: Tex Mantell
Sent: Friday, March 16, 2012 1:43 AM
Subject: RE: JabiruEngine-List: Re: worn valve guides
Wow, that=99s a fair number apart from mine. Do you think that
they can have been supplying oversized guides for 270 engines?
What=99s your plan to resolve? Send heads to Pete?
I changed mine without involving Jabiru UK, was in too much of a
hurry, regret it now.
Thanks, Clive
From: Tex Mantell [mailto:wb2ssj@rochester.rr.com]
Sent: 15 March 2012 22:02
To: James, Clive R
Subject: Re: JabiruEngine-List: Re: worn valve guides
yes, thats agood idea. Mine is #1206 3300
----- Original Message -----
From: James, Clive R
To: wb2ssj@rochester.rr.com
Sent: Thursday, March 15, 2012 3:07 PM
Subject: FW: JabiruEngine-List: Re: worn valve guides
Hi Tex, I read you posting about the valve guides. Do you have the
serial number of the engine?
Mine was 1460 and Christian says the Chilean one was 1482. If your
example was close maybe we can indicate and period that folk can look
out for?
Regards, Clive
(Esqual in UK, now with 46 hrs on it!)
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of
Martin Hone
Sent: 13 March 2012 20:30
To: jabiruengine-list@matronics.com
Subject: Re: JabiruEngine-List: Re: worn valve guides
I reckon that makes it a warranty issue, surely.....
Martin
On Tue, Mar 13, 2012 at 9:31 PM, Tex Mantell
<wb2ssj@rochester.rr.com> wrote:
<wb2ssj@rochester.rr.com>
Nick, thanks for the info. Have come to the same conclusion that the
guides were oversize for all the cylinders wore the same. Again thanks
for the info. Tex
----- Original Message ----- From: "xair899" <nickgeh@eircom.net>
To: <jabiruengine-list@matronics.com>
Sent: Tuesday, March 13, 2012 3:59 AM
Subject: JabiruEngine-List: Re: worn valve guides
<nickgeh@eircom.net>
Tex,
Here in the UK guides were found "worn" at less than 50hrs. Careful
measurement showed they were exactly 7.50mm bore, where the standard
guide should be 7.05mm. Looks suspiciously like human error!
Once the batch passed through the system, that particular problem
went away. Not sure what serial number engines were affected.
The majority of the oil fed to the heads is dumped on the inlet
valve rather than the exhaust which really needs it. Try to persuade it
to go where it would do more good - see Jabiru info on French site
"Contrails" for some ideas.
Nick
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=368330#368330
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ine-List"
target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List
MS -
k">http://forums.matronics.com
e -
-Matt Dralle, List Admin.
t="_blank">http://www.matronics.com/contribution
=======================
Message 2
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| Subject: | Re: putting things in perspective |
Pete, enough here on the web already, Will talk to you at Sun&fun.
Tex
----- Original Message -----
From: Pete Krotje
To: jabiruengine-list@matronics.com
Sent: Thursday, March 15, 2012 5:03 PM
Subject: RE: JabiruEngine-List: putting things in perspective
Tex,
Since you posted here as well I'll copy the response I sent to your
lightning-list posting:
Tex,
I gave you the facts as I have seen them over the years. I've sold a
lot of engines and very few valve guides. What do you want - some story
about huge valve guide problems that are not happening? I don't think I
misstated anything in my reply to you. This occurrence is evident in a
few cases around the world but not many when put in context of the
number of engines sold. In the USA when we hear of a valve guide issue
we fix it. If we should find a valve guide that was over size from the
factory we'll fix it at Jabiru's expense but we have not found and
engine yet with factory oversize guides. I do expect that I will find
one sooner or later IF there truly are engines with oversize guides sent
out by Jabiru.
Sorry to disappoint you in my response. I suppose I could have
commiserated with you and told you how awful your situation is but I
would much rather be honest and tell you what we are seeing and have
seen over the last 12 years. If you have a valve guide problem how come
we've not seen your heads here for diagnosis and repair? Do you want
the problem fixed or do you want to just complain about it.
Pete Krotje
Jabiru USA Sport Aircraft, LLC
931-680-2800
www.usjabiru.com
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of Tex
Mantell
Sent: Thursday, March 15, 2012 1:59 PM
To: jabiruengine-list@matronics.com; lightning-list@matronics.com
Subject: JabiruEngine-List: putting things in perspective
Don't you just love it "putting things In perspective" . Thank God for
the web site we have to share our experiences. If "putting things in
perspective" is to completely ignore a question related to ones
products, don't seem proper to me. I have two Jabiru engines and a
Lightning,and I am directly responsible for the sale of two airplanes
and about 6 engines. I love the products from Tennessee and am really
disappointed by the responses from Pete. Its quite evident from the
others around the world *there is a problem* and with the help and Ideas
gathered here on the web site I am sure to correct it.
Tex
http://www.matronics.com/Navigator?JabiruEngine-Listhttp://forums.matroni
cs.comhttp://www.matronics.com/contribution
Message 3
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For those interested here is a picture of the rocker box with the cover
off.(as if you are doing a head bolt check) If you see the discolored
area around the exhaust valve on the right,you might want to look
further into the situation.
Message 4
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| Subject: | Re: While Checking the Magnetos, intermittent shutdown |
Dan:
The cost of the diode is about $0.33, even Radio Shack has them.
What the diode is known as is "An anti-bounce diode".
What it does is:
When the relay is opened a REVERSE voltage (Reverse EMF) is induced into
the relays coil as the magnetic field collapses.
This collapse causes the relay to stay energized for a slightly longer
time. No big deal your A&P may say?!?!
But when the relay coil looses this reverse voltage SLOWLY - The BREAKING
of the contacts also happens SLOWLY which allows an ELECTRICAL ARC to form
on the contact points of the contractor.
After a while, when this happens enough tow things happen:
1 - The contact points get BURNED AWAY and
2 - A CARBON BUILD-UP
This cause the O! S#!+ syndrome; when you can not Power Up or START your
plane.
BOTH the Master & Starter Relay should have this (a) diode... OOoooo The
price just went up! It is now $0.66.
The diode is installed in REVERSE polarity to the relay coil and ground.
Barry
On Thu, Mar 15, 2012 at 3:34 AM, dwwilt <dwwilt@aol.com> wrote:
>
> I never found the reason for the failure. After checking everything out
> and ohming the system, the plane started fine and the mag check was fine.
> Unnerving to me, because there has to be a reason for the problem. I
> ordered a new switch and replaced it. I opened up the old switch and did
> not find anything unusual. However, with the Jabiru starter solenoid, the
> connections are not similar to those on other starter solenoids I am
> familiar with. I have not found where the surge protection diode was
> installed originally and I believe it was not installed. I did not do this
> part of the wiring on my plane. So, my question is, how do you connect the
> surge protection diode?
>
> --------
> Dennis
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=368570#368570
>
>
Message 5
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| Subject: | Re: While Checking the Magnetos, intermittent |
shutdown
Barry, thanks much for your explanation. Usually this kind of diode protec
ts against a surge current or a spike that could damage components. The pr
otection here is similar, but different as you explained. I really didn't
think about the circuit too much when I wrote up my question. I am an Elec
trical Engineer, but have not done any circuit analysis or design in many y
ears. Mostly, I do avionics systems work for a company that contracts with
the government. My real question was about the connectors that are a bit
different on the Jabiru starter relay than those I am familiar with. So, I
am going to do what I expected and remove the circular connector that is o
n the diode and connect the diode and the ignition switch to the starter re
lay using a single slide on connector for the plus side of the diode and co
nnect the negative side of the diode as delivered since that side used a cu
rcular connector.
Have a wonderful day,
Dennis
N616DW (Arion Lightning S/N 132)
-----Original Message-----
From: FLYaDIVE <flyadive@gmail.com>
Sent: Fri, Mar 16, 2012 9:34 am
Subject: Re: JabiruEngine-List: Re: While Checking the Magnetos, intermitte
nt shutdown
Dan:
The cost of the diode is about $0.33, even Radio Shack has them.
What the diode is known as is "An anti-bounce diode".
What it does is:
When the relay is opened a REVERSE voltage (Reverse EMF) is induced into th
e relays coil as the magnetic field collapses.
This collapse causes the relay to stay energized for a slightly longer time
. No big deal your A&P may say?!?!
But when the relay coil looses this reverse voltage SLOWLY - The BREAKING o
f the contacts also happens SLOWLY which allows an ELECTRICAL ARC to form o
n the contact points of the contractor.
After a while, when this happens enough tow things happen:
1 - The contact points get BURNED AWAY and
2 - A CARBON BUILD-UP
This cause the O! S#!+ syndrome; when you can not Power Up or START your pl
ane.
BOTH the Master & Starter Relay should have this (a) diode... OOoooo The pr
ice just went up! It is now $0.66.
The diode is installed in REVERSE polarity to the relay coil and ground.
Barry
On Thu, Mar 15, 2012 at 3:34 AM, dwwilt <dwwilt@aol.com> wrote:
I never found the reason for the failure. After checking everything out an
d ohming the system, the plane started fine and the mag check was fine. Un
nerving to me, because there has to be a reason for the problem. I ordered
a new switch and replaced it. I opened up the old switch and did not find
anything unusual. However, with the Jabiru starter solenoid, the connecti
ons are not similar to those on other starter solenoids I am familiar with.
I have not found where the surge protection diode was installed originall
y and I believe it was not installed. I did not do this part of the wiring
on my plane. So, my question is, how do you connect the surge protection
diode?
--------
Dennis
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=368570#368570
-List" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-Li
st
http://forums.matronics.com
le, List Admin.
="_blank">http://www.matronics.com/contribution
-= - The JabiruEngine-List Email Forum -
-= Use the Matronics List Features Navigator to browse
-= the many List utilities such as List Un/Subscription,
-= Archive Search & Download, 7-Day Browse, Chat, FAQ,
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Message 6
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| Subject: | Re: valve problem |
For the folks following this thread, I would urge some level of caution and
a high trust in USA Jabiru.
A couple years back we had a new Jab 3300 that had a real problem with
valves sticking. Ultimately the valves bent and several had to be replaced.
A casual notion would be that the valve guides were TOOOOO tight!!!
However, inspection by Pete K and the folks in Tennesee revealed the presence
of a gunky contaminate. It was that material that caused the valves to
gunk up and stick. The engine was torn down and checked, then reassembled.
Other than a clean up, touch up of the seats and new valves, nothing was
done. It is running fine today as far as I know.
The heads in Tex's picture could have a bent exhaust valve (which can come
from overheating), from dirt or problems with the seat, from overheating
cooking the oil in that spot, or perhaps other causes, not excluding a
problem with fuel contamination. We are not told of the number of hours on
the engine, the compression numbers obtained on multiple occasions, CHT's and
EGT's over time and other considerations. Frankly, if the compression
is up, particularly a differential compression check, I would not do
anything unless Pete, et al, said it was an indicator.
While Tex wants to make his own valve guides, that would not be the
solution I would pursue first. Having just discovered a cracked valve guide
in
a O-320 Lycoming, I tend to believe that some things just happen. Better
to replace with the correct part and simply move on.....if the guide is
indeed out of spec.
Doug Koenigsberg
In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time,
wb2ssj@rochester.rr.com writes:
For those interested here is a picture of the rocker box with the cover
off.(as if you are doing a head bolt check) If you see the discolored area
around the exhaust valve on the right,you might want to look further into the
situation.
Message 7
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| Subject: | Re: valve problem |
Guys - please take note:
In this age of instant communications it amazes me how information isolated
aviation people have become. I frequent different aviation online groups
and all have reported this SAME type of valve problem. It is nothing new.
What does amaze me it how technical engine manufactures can get. "Pete K
and the folks in Tennessee revealed the presence of a gunky contaminate."
That GUNK is known as coke, not the type that you drink but what happens
when you expose oil to high heat. This coke is a carbon base substance.
The coke attaches itself to the valve stem and guide; the coke is harder
than the steel of the valve or the valve guide and causes ware. This coke
hardens - And, the valve stem and valve guide ware allowing more oil leaks
into the space between the valve and guide. In engine design the valve is
harder than the guide so the guide wares more. As the coke builds up it
causes the valve to stick. History has shown when this happens the valve
sticks OPEN, in the DOWN position. Since the valve is DOWN it is met by
the UP coming piston. You can just imagine all the fun and sounds that
happen in a split second. What I do not know is: Dose the Jabiru have
an INTERFERENCE fit between the piston and valve? If not than all that may
happen is a loss of power; otherwise it's flying parts and vibration - If
you are lucky. This problem is more prevalent with engines that burn AvGas
but it does happen with MoGas also.
How do you prevent it? The jury is still out on that verdict. But, there
is a test that can be performed that gives one a better than average idea
on when it is happening. Go to the Lycoming web site and down load Service
Bulliten SB388C. It explains the required equipment and how to perform
what is know as "The Valve Wobble Test". Remember: The equipment will have
to be modified and the specs (Go-No Go) limits will have to be developed to
address the Jabiru Engine.
My thought on prevention is: COOL the valves and guides as much as you can.
Prevent the HEAT from burning the oil. If the oil does not burn coke will
not develop.
Side Note: Engine manufactures - If cooling does work you will have to
re-calculate the clearance between the valve stem and guide considering
the maleficent of expansion of the materials. Less heat means less
expansion unless you go with a NPO material.
Barry
On Fri, Mar 16, 2012 at 1:42 PM, <Kayberg@aol.com> wrote:
> **
> For the folks following this thread, I would urge some level of caution
> and a high trust in USA Jabiru.
>
> A couple years back we had a new Jab 3300 that had a real problem with
> valves sticking. Ultimately the valves bent and several had to be
> replaced. A casual notion would be that the valve guides were TOOOOO
> tight!!! However, inspection by Pete K and the folks in Tennesee revealed
> the presence of a gunky contaminate. It was that material that caused the
> valves to gunk up and stick. The engine was torn down and checked, then
> reassembled. Other than a clean up, touch up of the seats and new valves,
> nothing was done. It is running fine today as far as I know.
>
> The heads in Tex's picture could have a bent exhaust valve (which can come
> from overheating), from dirt or problems with the seat, from overheating
> cooking the oil in that spot, or perhaps other causes, not excluding a
> problem with fuel contamination. We are not told of the number of hours on
> the engine, the compression numbers obtained on multiple occasions, CHT's
> and EGT's over time and other considerations. Frankly, if the
> compression is up, particularly a differential compression check, I would
> not do anything unless Pete, et al, said it was an indicator.
>
> While Tex wants to make his own valve guides, that would not be the
> solution I would pursue first. Having just discovered a cracked valve
> guide in a O-320 Lycoming, I tend to believe that some things just
> happen. Better to replace with the correct part and simply move on.....if
> the guide is indeed out of spec.
>
>
> Doug Koenigsberg
>
> In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time,
> wb2ssj@rochester.rr.com writes:
>
> For those interested here is a picture of the rocker box with the cover
> off.(as if you are doing a head bolt check) If you see the discolored area
> around the exhaust valve on the right,you might want to look further into
> the situation.
>
> *
>
> *
>
>
Message 8
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| Subject: | Re: valve problem |
Just as an aside,
I believe the benefits of leaded fuel extend far beyond it's anti knock qua
lities.The cushioning and lubricating features make it worth the difference
in price as well as the fact that it stores without degradation.Any room f
or this thought in the valve guide discussion?Just my opinion.No offense me
ant.
G.Aman Jabiru 2200A approx.680 trouble free hrs so far all on 100LL
-----Original Message-----
From: Kayberg <Kayberg@aol.com>
Sent: Fri, Mar 16, 2012 1:43 pm
Subject: Re: JabiruEngine-List: valve problem
For the folks following this thread, I would urge some level of caution and
a high trust in USA Jabiru.
A couple years back we had a new Jab 3300 that had a real problem with valv
es sticking. Ultimately the valves bent and several had to be replaced.
A casual notion would be that the valve guides were TOOOOO tight!!! Howev
er, inspection by Pete K and the folks in Tennesee revealed the presence of
a gunky contaminate. It was that material that caused the valves to gunk
up and stick. The engine was torn down and checked, then reassembled. O
ther than a clean up, touch up of the seats and new valves, nothing was don
e. It is running fine today as far as I know.
The heads in Tex's picture could have a bent exhaust valve (which can come
from overheating), from dirt or problems with the seat, from overheating
cooking the oil in that spot, or perhaps other causes, not excluding a prob
lem with fuel contamination. We are not told of the number of hours on the
engine, the compression numbers obtained on multiple occasions, CHT's and
EGT's over time and other considerations. Frankly, if the compression is
up, particularly a differential compression check, I would not do anything
unless Pete, et al, said it was an indicator.
While Tex wants to make his own valve guides, that would not be the solutio
n I would pursue first. Having just discovered a cracked valve guide in a
O-320 Lycoming, I tend to believe that some things just happen. Better t
o replace with the correct part and simply move on.....if the guide is inde
ed out of spec.
Doug Koenigsberg
In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time, wb2ssj@roc
hester.rr.com writes:
For those interested here is a picture of the rocker box with the cover o
ff.(as if you are doing a head bolt check) If you see the discolored area
around the exhaust valve on the right,you might want to look further int
o the situation.
Message 9
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| Subject: | Re: valve problem |
Thank you for your coments , but we already know the whats the problem.
Tex
----- Original Message -----
From: Kayberg@aol.com
To: jabiruengine-list@matronics.com
Sent: Friday, March 16, 2012 1:42 PM
Subject: Re: JabiruEngine-List: valve problem
For the folks following this thread, I would urge some level of
caution and a high trust in USA Jabiru.
A couple years back we had a new Jab 3300 that had a real problem with
valves sticking. Ultimately the valves bent and several had to be
replaced. A casual notion would be that the valve guides were TOOOOO
tight!!! However, inspection by Pete K and the folks in Tennesee
revealed the presence of a gunky contaminate. It was that material
that caused the valves to gunk up and stick. The engine was torn down
and checked, then reassembled. Other than a clean up, touch up of the
seats and new valves, nothing was done. It is running fine today as far
as I know.
The heads in Tex's picture could have a bent exhaust valve (which can
come from overheating), from dirt or problems with the seat, from
overheating cooking the oil in that spot, or perhaps other causes, not
excluding a problem with fuel contamination. We are not told of the
number of hours on the engine, the compression numbers obtained on
multiple occasions, CHT's and EGT's over time and other considerations.
Frankly, if the compression is up, particularly a differential
compression check, I would not do anything unless Pete, et al, said it
was an indicator.
While Tex wants to make his own valve guides, that would not be the
solution I would pursue first. Having just discovered a cracked valve
guide in a O-320 Lycoming, I tend to believe that some things just
happen. Better to replace with the correct part and simply move
on.....if the guide is indeed out of spec.
Doug Koenigsberg
In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time,
wb2ssj@rochester.rr.com writes:
For those interested here is a picture of the rocker box with the
cover off.(as if you are doing a head bolt check) If you see the
discolored area around the exhaust valve on the right,you might want to
look further into the situation.
Message 10
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| Subject: | Re: valve problem |
Good Afternoon G.Aman,
I do like the stability aspects of 100LL, but I think any thoughts as to
the cushioning and lubrication qualities of leaded fuel are pure
unadulterated Old Wives' Tales.
The FAA ran a set of engines on an Aero Commander many years ago with one
engine being fed only leaded fuel and the other fed only unleaded fuel. The
one using unleaded fuel ran better, ran cleaner, and lasted easily through
TBO.
Lead is strictly a relatively low cost octane enhancer. If you do not need
the octane, don't use leaded fuel!
Too bad we do not have a source of unleaded aviation fuel. 80 octane would
be more than enough for most small engines. Without lead, the 100 LL mix is
good for 96 or 97 octane.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Downers Grove, Illinois
In a message dated 3/16/2012 3:14:21 P.M. Central Daylight Time,
zeprep251@aol.com writes:
Just as an aside,
I believe the benefits of leaded fuel extend far beyond it's anti knock
qualities.The cushioning and lubricating features make it worth the
difference in price as well as the fact that it stores without degradation.Any
room
for this thought in the valve guide discussion?Just my opinion.No offense
meant.
G.Aman Jabiru 2200A approx.680 trouble free hrs so far all on 100LL
Message 11
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| Subject: | Talk About Valves |
Hy, reading about some major problems with valves, here some photos of a
boroscope exhaust valves inspection on my 180hs Jab 3300A HL.
Waiting comments....
Best regards from Brazil
Wagner
Message 12
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| Subject: | Re: valve problem |
Barry, it wasn't coke. It wasn't carbon based. It was a yellowish
material that we believe was present in the mogas with ethanol. It showed up
in
less than 3 hours of running, hardly enough to cause significant carbon
deposits.
Doug
In a message dated 3/16/2012 3:27:41 P.M. Eastern Daylight Time,
flyadive@gmail.com writes:
Guys - please take note:
In this age of instant communications it amazes me how information
isolated aviation people have become. I frequent different aviation online groups
and all have reported this SAME type of valve problem. It is nothing new.
What does amaze me it how technical engine manufactures can get. "Pete K
and the folks in Tennessee revealed the presence of a gunky contaminate."
That GUNK is known as coke, not the type that you drink but what happens
when you expose oil to high heat. This coke is a carbon base substance. The
coke attaches itself to the valve stem and guide; the coke is harder than
the steel of the valve or the valve guide and causes ware. This coke
hardens - And, the valve stem and valve guide ware allowing more oil leaks into
the space between the valve and guide. In engine design the valve is harder
than the guide so the guide wares more. As the coke builds up it causes
the valve to stick. History has shown when this happens the valve sticks
OPEN, in the DOWN position. Since the valve is DOWN it is met by the UP
coming piston. You can just imagine all the fun and sounds that happen in a
split second. What I do not know is: Dose the Jabiru have an INTERFERENCE
fit between the piston and valve? If not than all that may happen is a loss
of power; otherwise it's flying parts and vibration - If you are lucky.
This problem is more prevalent with engines that burn AvGas but it does
happen with MoGas also.
How do you prevent it? The jury is still out on that verdict. But, there
is a test that can be performed that gives one a better than average idea
on when it is happening. Go to the Lycoming web site and down load Service
Bulliten SB388C. It explains the required equipment and how to perform
what is know as "The Valve Wobble Test". Remember: The equipment will have to
be modified and the specs (Go-No Go) limits will have to be developed to
address the Jabiru Engine.
My thought on prevention is: COOL the valves and guides as much as you
can. Prevent the HEAT from burning the oil. If the oil does not burn coke
will not develop.
Side Note: Engine manufactures - If cooling does work you will have to
re-calculate the clearance between the valve stem and guide considering the
maleficent of expansion of the materials. Less heat means less expansion
unless you go with a NPO material.
Barry
On Fri, Mar 16, 2012 at 1:42 PM, <_Kayberg@aol.com_
(mailto:Kayberg@aol.com) > wrote:
For the folks following this thread, I would urge some level of caution
and a high trust in USA Jabiru.
A couple years back we had a new Jab 3300 that had a real problem with
valves sticking. Ultimately the valves bent and several had to be replaced.
A casual notion would be that the valve guides were TOOOOO tight!!!
However, inspection by Pete K and the folks in Tennesee revealed the presence
of a gunky contaminate. It was that material that caused the valves to
gunk up and stick. The engine was torn down and checked, then reassembled.
Other than a clean up, touch up of the seats and new valves, nothing was
done. It is running fine today as far as I know.
The heads in Tex's picture could have a bent exhaust valve (which can come
from overheating), from dirt or problems with the seat, from overheating
cooking the oil in that spot, or perhaps other causes, not excluding a
problem with fuel contamination. We are not told of the number of hours on
the engine, the compression numbers obtained on multiple occasions, CHT's and
EGT's over time and other considerations. Frankly, if the compression
is up, particularly a differential compression check, I would not do
anything unless Pete, et al, said it was an indicator.
While Tex wants to make his own valve guides, that would not be the
solution I would pursue first. Having just discovered a cracked valve guide
in
a O-320 Lycoming, I tend to believe that some things just happen. Better
to replace with the correct part and simply move on.....if the guide
Message 13
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|
Obviously overheated
From: wb2ssj@rochester.rr.com
Subject: JabiruEngine-List: valve problem
For those interested here is a picture of the rocker box with the cover off
.(as if you are doing a head bolt check) If you see the discolored area aro
und the exhaust valve on the right=2Cyou might want to look further into th
e situation.
Message 14
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| Subject: | Re: valve problem |
Gary:
You have been corrupted! Brainwashed or what ever term you want to apply...
That is such a Old Wive's Tail that the old lady's mole is growing a beard.
The EPA took that malarkey and used it against the aviation industry.
Here is how it started: We as pilots use the term LEADED FUEL. The EPA
forced feed the public those words LEAD. And everyone knows you should not
Eat or Breathe LEAD.
AND when we clean our spark plugs we remove a solid particle that WE call
LEAD!
So, using that totally incorrect logic AND force feeding to the public, it
only goes to say: Engines are NOT 100% efficient so considering that it
only goes to prove that some of that lead is being exhausted and pumped
into the air! Also, since lead is a soft material and the exhaust valve is
open during intake some of the raw fuel is being pumped past the valve as
it closes. It MUST be CUSHIONING the valve! Ergo the
Oral Deification and development of the Old Wife's Tail.
RULE: If a lie is told long enough and loud enough it becomes the truth.
Barry
On Fri, Mar 16, 2012 at 4:13 PM, Gary Aman <zeprep251@aol.com> wrote:
> Just as an aside,
> I believe the benefits of leaded fuel extend far beyond it's anti knock
> qualities.The cushioning and lubricating features make it worth the
> difference in price as well as the fact that it stores without
> degradation.Any room for this thought in the valve guide discussion?Just my
> opinion.No offense meant.
> G.Aman Jabiru 2200A approx.680 trouble free hrs so far all on 100LL
>
>
> -----Original Message-----
> From: Kayberg <Kayberg@aol.com>
> To: jabiruengine-list <jabiruengine-list@matronics.com>
> Sent: Fri, Mar 16, 2012 1:43 pm
> Subject: Re: JabiruEngine-List: valve problem
>
> For the folks following this thread, I would urge some level of caution
> and a high trust in USA Jabiru.
>
> A couple years back we had a new Jab 3300 that had a real problem with
> valves sticking. Ultimately the valves bent and several had to be
> replaced. A casual notion would be that the valve guides were TOOOOO
> tight!!! However, inspection by Pete K and the folks in Tennesee revealed
> the presence of a gunky contaminate. It was that material that caused the
> valves to gunk up and stick. The engine was torn down and checked, then
> reassembled. Other than a clean up, touch up of the seats and new valves,
> nothing was done. It is running fine today as far as I know.
>
> The heads in Tex's picture could have a bent exhaust valve (which can come
> from overheating), from dirt or problems with the seat, from overheating
> cooking the oil in that spot, or perhaps other causes, not excluding a
> problem with fuel contamination. We are not told of the number of hours on
> the engine, the compression numbers obtained on multiple occasions, CHT's
> and EGT's over time and other considerations. Frankly, if the
> compression is up, particularly a differential compression check, I would
> not do anything unless Pete, et al, said it was an indicator.
>
> While Tex wants to make his own valve guides, that would not be the
> solution I would pursue first. Having just discovered a cracked valve
> guide in a O-320 Lycoming, I tend to believe that some things just
> happen. Better to replace with the correct part and simply move on.....if
> the guide is indeed out of spec.
>
>
> Doug Koenigsberg
>
> In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time,
> wb2ssj@rochester.rr.com writes:
>
> For those interested here is a picture of the rocker box with the cover
> off.(as if you are doing a head bolt check) If you see the discolored area
> around the exhaust valve on the right,you might want to look further into
> the situation.
>
> *
>
> tor?JabiruEngine-List">http://www.matronics.com/Navigator?JabiruEngine-List
> tp://forums.matronics.com
> bution">http://www.matronics.com/contribution
> *
>
> *
>
> *
>
>
Message 15
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| Subject: | Re: Talk About Valves |
Hi Wagner,
What sort of fuel are you burning ?
Cheers
Martin
On Sat, Mar 17, 2012 at 7:16 AM, Wagner <aeroeletrico@yahoo.com.br> wrote:
> Hy, reading about some major problems with valves, here some photos of a
> boroscope exhaust valves inspection on my 180hs Jab 3300A HL.
>
> Waiting comments....
>
> Best regards from Brazil
>
> Wagner
>
Message 16
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This was not coke but some foreign substance from the fuel
Pete
From: owner-jabiruengine-list-server@matronics.com
[mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of FLYaDIVE
Sent: Friday, March 16, 2012 2:27 PM
Subject: Re: JabiruEngine-List: valve problem
Guys - please take note:
In this age of instant communications it amazes me how information isolated
aviation people have become. I frequent different aviation online groups
and all have reported this SAME type of valve problem. It is nothing new.
What does amaze me it how technical engine manufactures can get. "Pete K
and the folks in Tennessee revealed the presence of a gunky contaminate."
That GUNK is known as coke, not the type that you drink but what happens
when you expose oil to high heat. This coke is a carbon base substance.
The coke attaches itself to the valve stem and guide; the coke is harder
than the steel of the valve or the valve guide and causes ware. This coke
hardens - And, the valve stem and valve guide ware allowing more oil leaks
into the space between the valve and guide. In engine design the valve is
harder than the guide so the guide wares more. As the coke builds up it
causes the valve to stick. History has shown when this happens the valve
sticks OPEN, in the DOWN position. Since the valve is DOWN it is met by the
UP coming piston. You can just imagine all the fun and sounds that happen
in a split second. What I do not know is: Dose the Jabiru have an
INTERFERENCE fit between the piston and valve? If not than all that may
happen is a loss of power; otherwise it's flying parts and vibration - If
you are lucky. This problem is more prevalent with engines that burn AvGas
but it does happen with MoGas also.
How do you prevent it? The jury is still out on that verdict. But, there
is a test that can be performed that gives one a better than average idea on
when it is happening. Go to the Lycoming web site and down load Service
Bulliten SB388C. It explains the required equipment and how to perform what
is know as "The Valve Wobble Test". Remember: The equipment will have to be
modified and the specs (Go-No Go) limits will have to be developed to
address the Jabiru Engine.
My thought on prevention is: COOL the valves and guides as much as you can.
Prevent the HEAT from burning the oil. If the oil does not burn coke will
not develop.
Side Note: Engine manufactures - If cooling does work you will have to
re-calculate the clearance between the valve stem and guide considering the
maleficent of expansion of the materials. Less heat means less expansion
unless you go with a NPO material.
Barry
On Fri, Mar 16, 2012 at 1:42 PM, <Kayberg@aol.com> wrote:
For the folks following this thread, I would urge some level of caution and
a high trust in USA Jabiru.
A couple years back we had a new Jab 3300 that had a real problem with
valves sticking. Ultimately the valves bent and several had to be replaced.
A casual notion would be that the valve guides were TOOOOO tight!!!
However, inspection by Pete K and the folks in Tennesee revealed the
presence of a gunky contaminate. It was that material that caused the
valves to gunk up and stick. The engine was torn down and checked, then
reassembled. Other than a clean up, touch up of the seats and new valves,
nothing was done. It is running fine today as far as I know.
The heads in Tex's picture could have a bent exhaust valve (which can come
from overheating), from dirt or problems with the seat, from overheating
cooking the oil in that spot, or perhaps other causes, not excluding a
problem with fuel contamination. We are not told of the number of hours on
the engine, the compression numbers obtained on multiple occasions, CHT's
and EGT's over time and other considerations. Frankly, if the compression
is up, particularly a differential compression check, I would not do
anything unless Pete, et al, said it was an indicator.
While Tex wants to make his own valve guides, that would not be the solution
I would pursue first. Having just discovered a cracked valve guide in a
O-320 Lycoming, I tend to believe that some things just happen. Better to
replace with the correct part and simply move on.....if the guide is indeed
out of spec.
Doug Koenigsberg
In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time,
wb2ssj@rochester.rr.com writes:
For those interested here is a picture of the rocker box with the cover
off.(as if you are doing a head bolt check) If you see the discolored area
around the exhaust valve on the right,you might want to look further into
the situation.
ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
Message 17
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| Subject: | Re: valve problem |
Bzzzzt... Wrong..
On 3/16/2012 10:36 PM, Naftali Horowitz wrote:
> Obviously overheated
>
> ------------------------------------------------------------------------
> From: wb2ssj@rochester.rr.com
> To: lightning-list@matronics.com; jabiruengine-list@matronics.com
> Subject: JabiruEngine-List: valve problem
> Date: Fri, 16 Mar 2012 06:45:42 -0400
>
> For those interested here is a picture of the rocker box with the
> cover off.(as if you are doing a head bolt check) If you see the
> discolored area around the exhaust valve on the right,you might want
> to look further into the situation.
> *
>
>
> *
Message 18
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|
| Subject: | Re: Talk About Valves |
Avgas 100ll
Wagner.
Em 16/03/2012, =C3-s 19:48, Martin Hone <aerobiz1@gmail.com> escreveu:
> Hi Wagner,
>
> What sort of fuel are you burning ?
>
> Cheers
>
> Martin
>
> On Sat, Mar 17, 2012 at 7:16 AM, Wagner <aeroeletrico@yahoo.com.br> wrote:
> Hy, reading about some major problems with valves, here some photos of a b
oroscope exhaust valves inspection on my 180hs Jab 3300A HL.
>
> Waiting comments....
>
> Best regards from Brazil
>
> Wagner
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
Message 19
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|
| Subject: | Re: Talk About Valves |
QXQgZmlyc3QgZ2xhbmNlLCBpdCBhcHBlYXJzIHRvIGJlIHJ1bm5pbmcgb2suCgpNYXJ0eQoKT24g
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Message 20
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|
| Subject: | Re: valve problem |
The engine the kayberg is talking about was not burned oil or fuel deposit. t
his "gunk" or "coke" as you call it was not found in the rocker box on this p
articular engine. It had gummed up the mechanical fuel pump, carb, intake pl
enum and tubes, and the intake valves only at the portion which is exposed t
o the incoming mix. This was not a oil burn or lead deposit. It had formed f
rom a fuel contaminate and easily disolved with parts wash and solvent. It w
as tanish in color and clear like a varnsih.
I would belive everything else but it was not oil or lead, it had contaminat
ed and built up on everything from the fuel tanks in. I know because i rebui
lt that engine.
Nick
Sent from my pocket
On Mar 16, 2012, at 2:26 PM, FLYaDIVE <flyadive@gmail.com> wrote:
> Guys - please take note:
>
> In this age of instant communications it amazes me how information isolate
d aviation people have become. I frequent different aviation online groups a
nd all have reported this SAME type of valve problem. It is nothing new. Wh
at does amaze me it how technical engine manufactures can get. "Pete K and t
he folks in Tennessee revealed the presence of a gunky contaminate." That G
UNK is known as coke, not the type that you drink but what happens when you e
xpose oil to high heat. This coke is a carbon base substance. The coke att
aches itself to the valve stem and guide; the coke is harder than the steel o
f the valve or the valve guide and causes ware. This coke hardens - And, th
e valve stem and valve guide ware allowing more oil leaks into the space bet
ween the valve and guide. In engine design the valve is harder than the gui
de so the guide wares more. As the coke builds up it causes the valve to st
ick. History has shown when this happens the valve sticks OPEN, in the DOWN
position. Since the valve is DOWN it is met by the UP coming piston. You c
an just imagine all the fun and sounds that happen in a split second. What I
do not know is: Dose the Jabiru have an INTERFERENCE fit between the pisto
n and valve? If not than all that may happen is a loss of power; otherwise i
t's flying parts and vibration - If you are lucky. This problem is more pre
valent with engines that burn AvGas but it does happen with MoGas also.
>
> How do you prevent it? The jury is still out on that verdict. But, there
is a test that can be performed that gives one a better than average idea o
n when it is happening. Go to the Lycoming web site and down load Service B
ulliten SB388C. It explains the required equipment and how to perform what i
s know as "The Valve Wobble Test". Remember: The equipment will have to be m
odified and the specs (Go-No Go) limits will have to be developed to address
the Jabiru Engine.
>
> My thought on prevention is: COOL the valves and guides as much as you can
. Prevent the HEAT from burning the oil. If the oil does not burn coke will
not develop.
> Side Note: Engine manufactures - If cooling does work you will have to re
-calculate the clearance between the valve stem and guide considering the ma
leficent of expansion of the materials. Less heat means less expansion unle
ss you go with a NPO material.
>
> Barry
>
>
>
> On Fri, Mar 16, 2012 at 1:42 PM, <Kayberg@aol.com> wrote:
> For the folks following this thread, I would urge some level of caution an
d a high trust in USA Jabiru.
>
> A couple years back we had a new Jab 3300 that had a real problem with val
ves sticking. Ultimately the valves bent and several had to be replaced. A
casual notion would be that the valve guides were TOOOOO tight!!! However
, inspection by Pete K and the folks in Tennesee revealed the presence of a g
unky contaminate. It was that material that caused the valves to gunk up a
nd stick. The engine was torn down and checked, then reassembled. Other t
han a clean up, touch up of the seats and new valves, nothing was done. It i
s running fine today as far as I know.
>
> The heads in Tex's picture could have a bent exhaust valve (which can come
from overheating), from dirt or problems with the seat, from overheating c
ooking the oil in that spot, or perhaps other causes, not excluding a proble
m with fuel contamination. We are not told of the number of hours on the en
gine, the compression numbers obtained on multiple occasions, CHT's and EGT'
s over time and other considerations. Frankly, if the compression is up, p
articularly a differential compression check, I would not do anything unless
Pete, et al, said it was an indicator.
>
> While Tex wants to make his own valve guides, that would not be the soluti
on I would pursue first. Having just discovered a cracked valve guide in a
O-320 Lycoming, I tend to believe that some things just happen. Better to
replace with the correct part and simply move on.....if the guide is indeed
out of spec.
>
>
> Doug Koenigsberg
>
> In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time, wb2ssj@ro
chester.rr.com writes:
> For those interested here is a picture of the rocker box with the cover of
f.(as if you are doing a head bolt check) If you see the discolored area aro
und the exhaust valve on the right,you might want to look further into the s
ituation.
>
>
> ist" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-Lis
t
> tp://forums.matronics.com
> _blank">http://www.matronics.com/contribution
>
>
>
>
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Message 21
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| Subject: | Re: valve problem |
Could the substance be epoxy or a tank sealer? I know many epoxies will
dissolve in ethanol laced fuel and some will dissolve in regular fuel. I have
seen fuel systems clogged with dissolved epoxy, a brownest color. It is
nasty stuff.
Greg
Jabiru 2200
In a message dated 3/16/2012 6:36:41 P.M. Central Daylight Time,
vettin74@yahoo.com writes:
The engine the kayberg is talking about was not burned oil or fuel
deposit. this "gunk" or "coke" as you call it was not found in the rocker box
on
this particular engine. It had gummed up the mechanical fuel pump, carb,
intake plenum and tubes, and the intake valves only at the portion which is
exposed to the incoming mix. This was not a oil burn or lead deposit. It had
formed from a fuel contaminate and easily disolved with parts wash and
solvent. It was tanish in color and clear like a varnsih.
I would belive everything else but it was not oil or lead, it had
contaminated and built up on everything from the fuel tanks in. I know because
i
rebuilt that engine.
Nick
Sent from my pocket
On Mar 16, 2012, at 2:26 PM, FLYaDIVE <_flyadive@gmail.com_
(mailto:flyadive@gmail.com) > wrote:
Guys - please take note:
In this age of instant communications it amazes me how information
isolated aviation people have become. I frequent different aviation online groups
and all have reported this SAME type of valve problem. It is nothing new.
What does amaze me it how technical engine manufactures can get. "Pete K
and the folks in Tennessee revealed the presence of a gunky contaminate."
That GUNK is known as coke, not the type that you drink but what happens
when you expose oil to high heat. This coke is a carbon base substance. The
coke attaches itself to the valve stem and guide; the coke is harder than
the steel of the valve or the valve guide and causes ware. This coke
hardens - And, the valve stem and valve guide ware allowing more oil leaks into
the space between the valve and guide. In engine design the valve is
harder than the guide so the guide wares more. As the coke builds up it causes
the valve to stick. History has shown when this happens the valve sticks
OPEN, in the DOWN position. Since the valve is DOWN it is met by the UP
coming piston. You can just imagine all the fun and sounds that happen in a
split second. What I do not know is: Dose the Jabiru have an INTERFERENCE
fit between the piston and valve? If not than all that may happen is a loss
of power; otherwise it's flying parts and vibration - If you are lucky.
This problem is more prevalent with engines that burn AvGas but it does
happen with MoGas also.
How do you prevent it? The jury is still out on that verdict. But, there
is a test that can be performed that gives one a better than average idea
on when it is happening. Go to the Lycoming web site and down load Service
Bulliten SB388C. It explains the required equipment and how to perform
what is know as "The Valve Wobble Test". Remember: The equipment will have
to be modified and the specs (Go-No Go) limits will have to be developed to
address the Jabiru Engine.
My thought on prevention is: COOL the valves and guides as much as you
can. Prevent the HEAT from burning the oil. If the oil does not burn coke
will not develop.
Side Note: Engine manufactures - If cooling does work you will have to
re-calculate the clearance between the valve stem and guide considering the
maleficent of expansion of the materials. Less heat means less expansion
unless you go with a NPO material.
Barry
On Fri, Mar 16, 2012 at 1:42 PM, <_Kayberg@aol.com_
(mailto:Kayberg@aol.com) > wrote:
For the folks following this thread, I would urge some level of caution
and a high trust in USA Jabiru.
A couple years back we had a new Jab 3300 that had a real problem with
valves sticking. Ultimately the valves bent and several had to be replaced.
A casual notion would be that the valve guides were TOOOOO tight!!!
However, inspection by Pete K and the folks in Tennesee revealed the presence
of a gunky contaminate. It was that material that caused the valves to
gunk up and stick. The engine was torn down and checked, then reassembled.
Other than a clean up, touch up of the seats and new valves, nothing was
done. It is running fine today as far as I know.
The heads in Tex's picture could have a bent exhaust valve (which can come
from overheating), from dirt or problems with the seat, from overheating
cooking the oil in that spot, or perhaps other causes, not excluding a
problem with fuel contamination. We are not told of the number of hours on
the engine, the compression numbers obtained on multiple occasions, CHT's and
EGT's over time and other considerations. Frankly, if the compression
is up, particularly a differential compression check, I would not do
anything unless Pete, et al, said it was an indicator.
While Tex wants to make his own valve guides, that would not be the
solution I would pursue first. Having just discovered a cracked valve guide
in
a O-320 Lycoming, I tend to believe that some things just happen. Better
to replace with the correct part and simply move on.....if the guide is
indeed out of spec.
Doug Koenigsberg
In a message dated 3/16/2012 6:51:50 A.M. Eastern Daylight Time,
_wb2ssj@rochester.rr.com_ (mailto:wb2ssj@rochester.rr.com) writes:
For those interested here is a picture of the rocker box with the cover
off.(as if you are doing a head bolt check) If you see the discolored area
around the exhaust valve on the right,you might want to look further into the
situation.
ist"
target="_blank">_http://www.matronics.com/Navigator?JabiruEngine-List_ (http://www.matronics.com/Navigator?JabiruEngine-List)
tp://forums.matronics.com
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