Today's Message Index:
----------------------
1. 05:57 AM - Re: Re: Header Tank Venting (Michael Logan)
2. 06:31 AM - Re: Re: Header Tank Venting (Noel Loveys)
3. 06:31 AM - Re: Re: Header Tank Venting (Noel Loveys)
4. 04:47 PM - Re: Header Tank Venting (JetPilot)
5. 05:00 PM - Re: Note on Ethanol (JetPilot)
6. 07:08 PM - Re: Re: Note on Ethanol (Guy Buchanan)
7. 09:54 PM - Re: Re: Note on Ethanol (Paul A. Franz, P.E.)
Message 1
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Subject: | Re: Header Tank Venting |
Also, don't fly with your flaps down for very long. Even at half full
tanks, you will run out of fuel and the engine will quit. Don't ask me how
I know.
Mike Logan
Series 5
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn Matteson
Sent: Friday, October 17, 2008 6:54 PM
Subject: Re: Kitfox-List: Re: Header Tank Venting
Noel-
I also have a clear vent line running up to my right tank, which is
equal in size to the left tank. However, I can see my vent line even
with the header tank behind the right side of the seat. My fuel line
and the vent line run parallel to the diagonal braces behind the
seat, and all I need to do is glance over my right shoulder
occasionally to check for fuel in both the clear glass Purolator
filter, and the clear vent line. I only *need* to do this when I know
that the fuel tanks are getting low, but I check it every so often
just out of habit. Pucker time comes when I allow myself to get low
on fuel and have to make a descent. Under these conditions...and I've
done this maybe 4-5 times (bad, Lynn, BAD)...like Guy suggested, just
leveling off for a moment will let some fuel fill the header, shut
off the light, and the pucker relaxes.
Lynn Matteson
Kitfox IV Speedster
Jabiru 2200, 572hrs
Sensenich 62x46
flying again after rebuild, and new Electroair direct-fire ignition
system
On Oct 17, 2008, at 6:21 PM, Noel Loveys wrote:
>
> Lynn:
>
> What you did was one of the things my flight instructor made me
> practice as
> part of a forced approach. Even the certified spam cans have
> issues with
> fuel delivery form the wing tanks on occasion.
>
> My plane only has a vent to the right wing tank.. The left tank is
> only
> half the size of the right and yes I do have unequal fuel flow. I
> also have
> a clear section in the vent line so I can see when fuel in the
> header starts
> to run out long before it does. When I install the 912 I was
> thinking about
> relocating the header behind the seat. In that location I will no
> longer be
> able to see the vent line.
>
> Noel
>
> -----Original Message-----
> From: owner-kitfox-list-server@matronics.com
> [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Lynn
> Matteson
> Sent: Friday, October 17, 2008 3:26 PM
> To: kitfox-list@matronics.com
> Subject: Re: Kitfox-List: Re: Header Tank Venting
>
>
> I had uneven flow on ONE day....I was within 8 minutes of the
> airport, and the low-fuel light came on, indicating 15 minutes of
> fuel left. I noticed there was plenty of fuel in the left tank, so I
> banked a bit to the right, sending that fuel into my header tank, and
> I watched as the vent line filled up, the low-fuel light went off,
> and I flew without incident into the airport to get 22 gallons into
> my 26 (27 with header ) gallon (total) tanks. I may regret saying
> this, but each pilot should know how his/her fuel system works, and
> what can be done in a pinch to remedy a problem...either that or get
> fuel more often.
>
> Lynn Matteson
> Kitfox IV Speedster
> Jabiru 2200, 572hrs
> Sensenich 62x46
> flying again after rebuild, and new Electroair direct-fire ignition
> system
>
>
> On Oct 17, 2008, at 1:03 PM, n85ae wrote:
>
>>
>> Header vents to both tanks, is usefull for equalizing pressure in
>> the fuel
>> tanks. This is the culprit for the uneven fuel flow problems in
>> kitfoxes.
>> All it take is a slight pressure differential, and you'll see a lot
>> more fuel
>> flow from one tank than the other.
>>
>> Jeff.
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p 9194#209194
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
Message 2
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Subject: | Re: Header Tank Venting |
To keep it short... Follow the plans and vent the header tank! Forget
about valves and breathers. Venting to both tanks sounds interesting but
will accomplish nothing except an increase in weight and complexity.
Noel Loveys
AME Intern, RPP
Kitfox III-A
Ivo IFA, Aerocet 1100 floats
-----Original Message-----
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of paul wilson
Sent: Friday, October 17, 2008 9:49 PM
Subject: Re: Kitfox-List: Re: Header Tank Venting
Steve.
NO -NO -NO You do not understand.
You are getting advice from someone who has no understanding of the
physics of fluid flow. You must vent the header. Valves in the header
tank vents are just plain crazy..
Follow the instructions in the build manual. The factory guys are
real engineers and have thought thru many things you may not even
consider. And if you don't have the latest fuel system version go get
it. And if you have a flying system that is not the latest system
change it. As several have pointed out this in not the place to come
up with something that will kill you.
Remember screwed up fuel systems cause the most downed Kitfoxes of
any other kind of failure. Probably because the builder did not
understand the factory setup and changed it to his own design. Or
just did not follow the instructions.
Please Read Andys message below and try to understand it
Paul
======
Just as a word clarification, so that terms aren't used
incorrectly. The fuel system in a Kitfox is "gravity feed" and fuel
pressure to the carb or engine fuel pump is "head pressure" from a
gravity fed fuel tank. Strictly gravity only. There is no "siphon
action". Designers have to determine that the fuel tank is high
enough in normal flying/attitudes (nose high/nose low) and fuel line
size adequate to provide a certain fuel pressure or head pressure for
the fuel consumption of the engine used. If your engine installation
requires additional pressure to the engine pump than head pressure
can provide, an electric pump must be installed prior to the engine
pump or carb (ala low wing aircraft). Fuel line size and head
pressure to the engine is all that insures that an adequate supply of
fuel is maintained to the metering device, unless you have a fuel
pump located at each tank outlet to supply increased fuel flow. Most
small aircraft under 140 hp, 3/8" line is used, that will that will
supply more enough fuel for engine consumption. As engines get
larger, fuel line size goes up, 1/2", 5/8", etc. The only time fuel
is "sucked" or "siphoned" from a tank is if you have a pump located
at the tank.
It is extremely important that the fuel lines and the vent lines be
angled down to the header tank or on a constant slope, problem areas
are at the wing pivot and the horizontal routing to the header
tank. Especially in the vent line. Air and fuel must have an
unimpeded path and a way to get out and into the upper wing tank, if
both lines to one tank have a low or high spot you could run into a
fuel lock situation on that side. Installed correctly and under
normal flying and fuel conditions, the vent line has fuel in it and
should correspond to the level of fuel in the tank. In a long,
steep, nose down descent with low fuel, your fuel pickup will be
higher than the fuel level in the tank, as the fuel runs to forward
to the front of the tank. The tank is still vented, fuel to the
header tank is supplied only by the remaining fuel in the fuel line
from the pickup to the header tank. Leveling off routinely will then
raise the fuel level above the fuel pickup/screen and will flow back
down into the header tank. The air being displace by the fuel will
go up the vent line and into the fuel tank. If the vent were blocked
then air would have to travel upstream against the fuel going down
into the header tank. If it is on a constant slope this should not
cause a problem other than fuel will not fill the header tank as fast
as it has to make room for air in the line going up. This is why the
vent line is important.
If you look at aerobatic biplanes with a center section upper wing
mounted fuel tank, you will see a forward fuel pickup. This is for
nose down attitudes. Most Cessna's have a forward pick up location,
we can't because of the folding wing design. The fuel line would
have to run down the forward doorpost frame. (Which it does in a Cessna)
There is nothing wrong with a single vent line to one tank or a vent
line to each tank. Because we have a folding wing design we cannot
have a interconnecting vent line (wing tank-to-wing tank) like a
Cessna that they use to help even the fuel burn from each wing. In a
perfect world (no slip nor skid, wings level, no turbulence, etc)
Kitfox dual vent lines are used to keep fuel burn equal. The fuel
vents on the "filler caps" provide a very slight positive pressure in
the tanks, but mainly to fill the void of used fuel. Make sure the
caps are on correct and the gaskets are sealing. One of the reasons
for the long periscope vent line on the cap is to get the vent into
static atmospheric air. The low pressure on top of the wing where
the fuel cap is can cause siphoning of fuel, which is why a gasket
check is a good idea.
The reason that the vent line from the header tank needs to be a
constant slope to the tank vent boss is to ensure that you don't
create a "trap" for air. A dual vent line system helps to ensure
positive flow to the engine just incase one vent line were to become
blocked.
Depending on your engine installation it is possible run the fuel low
enough that there is not enough head pressure to supply the carb,
even though there may be fuel in the header tank. I suggest a
standby electric fuel pump (Faucet 4-6 gph) be mounted below the
header tank outlet that can be turn on during takeoff/landing and low
fuel situations. I installed one in my fuel system. To insure
positive pressure.
I would:
I would check the fuel caps first to make sure they are not blocked,
pointing forward and the gasket seals.
Ensure that the fuel and vent lines to each tank are on a constant
slope to the tank.
Verify that the fuel level in the vent line corresponds to the level
of fuel in the tank.
Andy
============
At 06:29 AM 10/17/2008, you wrote:
>
>Obviously there are differing thoughts on this issue. What I am
>getting so far is that it MAY not be necessary to close the venting,
>but closing the venting will not harm anything and MAY actually HELP
>in some instances. Would that be a accurate summary?
>
>--------
>Steve Wilson
>Huntsville, UT
>Kitfox Model 1- 85DD
>912A / 3 Blade Warp Drive
>Convertible Nosewheel & Tailwheel
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p 9161#209161
>
>
Message 3
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Subject: | Re: Header Tank Venting |
IMHO most fuel starvation will come from blocked cap breathers on the left
tank.
Sigtaturea
Noel Loveys
Campbellton, NL, Canada
CDN AME intern, PP-Rec
C-FINB, Kitfox III-A
Ivo IFA, Aerocet 1100 floats
noelloveys@yahoo.ca
From: owner-kitfox-list-server@matronics.com
[mailto:owner-kitfox-list-server@matronics.com] On Behalf Of paul wilson
Sent: Friday, October 17, 2008 9:55 PM
Subject: Re: Kitfox-List: Re: Header Tank Venting
Lots of examples Just do your homework
Agree. Asymmetrical fuel flow from the tanks has nothing to do with
starvation. Fixes for it are not necessary. Just follow the details on the
install and the issue will go away. Nice fat lines are also good and no
restrictions in any of the lines are also good. No filter or other
components in the header to tank lines helps that situation.
Paul
At 09:26 AM 10/17/2008, you wrote:
If as you suggest the header tank vent was OFF then in Lowell's example or
other similar scenario the automatic refilling of the header tank would be
prevented and air/fuel blockages of the two feed lines from the wing tanks
WOULD likely slow or prevent flow to the header tank and encourage fuel
starvation with adequate fuel remaining in the wings.
Add my name to the many with asymetrical fuel flow from the tanks but no
evidence of the header tank being deprived. I don't have a low fuel warning
but there are many out there to monitor the possiblity of starvation. Were
there any warnings that were triggered as a result of the asymetrical draw.
What are the specifics of the "many crashes due to fuel starvation"? Sounds
like urban myth to me.
John Kerr
Classic IV, 912ul, 780 hours.
Logan UT
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Message 4
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Subject: | Re: Header Tank Venting |
Andy Is Correct,
Putting valves and closing the vent on the header tank is just plain dangerous
and dumb. Someone is giving out very bad and dangerous advice. There are things
that this " Bad Advice " person did not take into consideration. It would
take a lot of research and evidence before I would even think about changing
the Kitfox design. EAA has people very well versed in fuel systems, I would
at least talk to some real experts before I changed a good and proven design.
Mike
--------
"NO FEAR" - If you have no fear you did not go as fast as you could
have !!!
Kolb MK-III Xtra, 912-S
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p 9308#209308
Message 5
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Subject: | Re: Note on Ethanol |
Making and Burning Ethanol as fuel is the greatest Environmental distster this
planet has ever faced. Noel is correct, producing ethanol takes more energy
and creates more CO 2 than just burning the gasoline, but it get much worse [Shocked]
Being that we are now burning Food for fuel, to make up for the food shortage,
Forests in Brazil, Malaysia and all over the world are being slashed at a much
greater rate than ever before. The ethanol demand is driving this. It takes
enough corn to produce 20 gallons of ethanol to feed a person for a year, did
we forget all about morality and the starving people on this planet ? Why
would we do such a stupid thing, CORRUPTION. Special interests, farmers votes,
there is enough money behind this to make it happen, even though it is harming
the planet immensely. We have the best government money can buy.
I forgot to mention the most important aspect of ethanol, it causes problems when
used in our airplanes [Evil or Very Mad]
Mike [Evil or Very Mad]
--------
"NO FEAR" - If you have no fear you did not go as fast as you could
have !!!
Kolb MK-III Xtra, 912-S
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p 9309#209309
Message 6
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Subject: | Re: Note on Ethanol |
At 05:00 PM 10/18/2008, you wrote:
>I forgot to mention the most important aspect of ethanol, it causes
>problems when used in our airplanes [Evil or Very Mad]
Thanks, Mike, for making this post at least tangentially aviation
related. However this thread was beat to death quite recently, so I
am going to ask you and others to take it off list.
Thanks,
Guy Buchanan, Kitfox List Moderator
San Diego, CA
K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.
Message 7
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Subject: | Re: Note on Ethanol |
On Sat, October 18, 2008 5:00 pm, JetPilot wrote:
>
> Making and Burning Ethanol as fuel is the greatest Environmental distster this
planet
> has ever faced. Noel is correct, producing ethanol takes more energy and creates
> more CO 2 than just burning the gasoline, but it get much worse [Shocked]
clip clip
This an interesting topic however, this is not the proper forum for it. It's a
good
idea to discuss closely related subject matter to the building and operating of
a
Kitfox and powering one. If the topic drifts too far off, the maillist will lose
it's
usefulness and some participants will lose interest. I don't think there needs
to be
silly restrictions on what you can discuss and quoting URLs for products we find
seems
fine to me too.
Just for drill there is a nice section at the bottom of this page on Kitfox-List
Usage
Guidelines:
<http://www.matronics.com/FAQ/Kitfox-List.htm>
It's actually pretty good practice, IMHO, to follow these guidelines.
--
Paul A. Franz, P.E.
PAF Consulting Engineers
Office 425.440.9505
Cell 425.241.1618
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