The Murphy Builders Site

I have never liked the single fuel pick up used on the SR and Moose, seems
like with the extra range tanks with low fuel you could uncover the fuel
pick up on approach. I was considering going with a fore and aft pick up as
some have done. However my tanks will be all sealed up (QB wing) when I get
them.

After talking with Robin at MAM he said they tested it in all attitudes and
had no problem, however that was with only a 40 gallon tank on one side and
a 30 on the other. He said if he did his own he would consider a header
tank under the right seat floor. I think this may be a good idea. Looks
like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the header
tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or does it
act like just a big piece of fuel line?

Thanks,
Scott
SR#174





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Hi Scott, I intend to use a header tank also, but mounted on the firewall.
I will be doing this though because of fuel injection on the Subaru. Using
fuel injection I need to have a return line, and it's much simpler to return
to a header tank than to the wing tanks. Installations like this that I
have seen had no vent as the wing tanks just keep the header full.

Mike
195SR

----- Original Message -----
From: "Scott & Leere' Aldrich" <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 7:48 AM
Subject: Moose Fuel Header Tank

I have never liked the single fuel pick up used on the SR and Moose, seems
like with the extra range tanks with low fuel you could uncover the fuel
pick up on approach. I was considering going with a fore and aft pick up

as

some have done. However my tanks will be all sealed up (QB wing) when I

get

them.

After talking with Robin at MAM he said they tested it in all attitudes

and

had no problem, however that was with only a 40 gallon tank on one side

and

a 30 on the other. He said if he did his own he would consider a header
tank under the right seat floor. I think this may be a good idea. Looks
like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the header
tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or does

it

act like just a big piece of fuel line?

Thanks,
Scott
SR#174

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Hey Mike,

Was there not some comment made recently about heating problems with
fire-wall mounted gascolators, to the point of mounting behind the
seats as an alternative? Would a fire-wall mounted header tank not be
more susceptible to heat than just the gascolator?

And further to header tank suggestions, I've recently seen a pair of
header tanks on a GlaStar (high wing gravity feed, as is the Rebel).
These were about 10 inches deep by about 4 inch diameter, but formed
into an oval shape, so the "diameter" was like 2" X 5". (This could
well have been a piece of "strut" tubing, with welded end caps and
fittings.) These each had three "ports". One was on the bottom and
fed the engine, one at the top is the feed from its wing-tank, and
the other one at the top I assume was a vent, but I could not see
where it "vented" to, and more interestingly how deep they reach into
the header tank. These were mounted to the cabin frame (the GlaStar
is a composite, but with a crash cage) just behind the seats at about
1/2 way between cabin roof and floor. Easy to see and service, and
occupies no "useful space" the way they are tucked in. Serves lots of
purposes I would think, not the least of which is nose down attitude
during approach with low fuel.

Just a comment, but isn't some of what you are suggesting with the
separate tanks a bit risky in the un-known, versus using fuel transfer
pumps?

Have a good one.

Brian Lawson
Windsor, Ontario.

ps...Just worked up a nice sweat cutting the grass which was getting
pretty long. It's pushing 70 degrees here today. Heh heh. Should we
be sending shovels or St. Bernards up your way?
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
On Thu, 11 Apr 2002 08:18:35 -0800, you wrote:

Hi Scott, I intend to use a header tank also, but mounted on the firewall.
I will be doing this though because of fuel injection on the Subaru. Using
fuel injection I need to have a return line, and it's much simpler to return
to a header tank than to the wing tanks. Installations like this that I
have seen had no vent as the wing tanks just keep the header full.

Mike
195SR

----- Original Message -----
From: "Scott & Leere' Aldrich" <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 7:48 AM
Subject: Moose Fuel Header Tank

I have never liked the single fuel pick up used on the SR and Moose, seems
like with the extra range tanks with low fuel you could uncover the fuel
pick up on approach. I was considering going with a fore and aft pick up

as

some have done. However my tanks will be all sealed up (QB wing) when I

get

them.

After talking with Robin at MAM he said they tested it in all attitudes

and

had no problem, however that was with only a 40 gallon tank on one side

and

a 30 on the other. He said if he did his own he would consider a header
tank under the right seat floor. I think this may be a good idea. Looks
like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the header
tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or does

it

act like just a big piece of fuel line?

Thanks,
Scott
SR#174

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I am planning on using a Chevy Engine. The fuel pressure required is 50-60 PSI. My thought was similar to those expressed here... to put a tank under the right seat. My thought was to feed that tank with a low pressure gravity feed and utilize dual high pr
essure fuel pumps with check valves from their to the engine. Because this would be the low point in the system, it would likely be necessary to have a drain like many gascolators. Dual pumps are for redundancy and the check valves are to ensure that should
one pump fail, the flow will be to the engine and not just return to the header. Fluid has a dendancy to follow the path of least resistance which would be back into the header tank. Part of the challenge here will be to ensure the header is filled from ab
ove and drained from the bottom. All shutoff valves would be after the fuel pumps to ensure fuel flow could be stopped to the engine in the event a problem up there developed.

Rick Muller
70SR

On Thu, 11 Apr 2002 19:59:22 GMT Brian Lawson <lawsonb@mnsi.net> wrote:



Hey Mike,

Was there not some comment made recently about heating problems with
fire-wall mounted gascolators, to the point of mounting behind the
seats as an alternative? Would a fire-wall mounted header tank not be
more susceptible to heat than just the gascolator?

And further to header tank suggestions, I've recently seen a pair of
header tanks on a GlaStar (high wing gravity feed, as is the Rebel).
These were about 10 inches deep by about 4 inch diameter, but formed
into an oval shape, so the "diameter" was like 2" X 5". (This could
well have been a piece of "strut" tubing, with welded end caps and
fittings.) These each had three "ports". One was on the bottom and
fed the engine, one at the top is the feed from its wing-tank, and
the other one at the top I assume was a vent, but I could not see
where it "vented" to, and more interestingly how deep they reach into
the header tank. These were mounted to the cabin frame (the GlaStar
is a composite, but with a crash cage) just behind the seats at about
1/2 way between cabin roof and floor. Easy to see and service, and
occupies no "useful space" the way they are tucked in. Serves lots of
purposes I would think, not the least of which is nose down attitude
during approach with low fuel.

Just a comment, but isn't some of what you are suggesting with the
separate tanks a bit risky in the un-known, versus using fuel transfer
pumps?

Have a good one.

Brian Lawson
Windsor, Ontario.

ps...Just worked up a nice sweat cutting the grass which was getting
pretty long. It's pushing 70 degrees here today. Heh heh. Should we
be sending shovels or St. Bernards up your way?
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
On Thu, 11 Apr 2002 08:18:35 -0800, you wrote:

Hi Scott, I intend to use a header tank also, but mounted on the firewall.
I will be doing this though because of fuel injection on the Subaru. Using
fuel injection I need to have a return line, and it's much simpler to return
to a header tank than to the wing tanks. Installations like this that I
have seen had no vent as the wing tanks just keep the header full.

Mike
195SR

----- Original Message -----
From: "Scott & Leere' Aldrich" <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 7:48 AM
Subject: Moose Fuel Header Tank

I have never liked the single fuel pick up used on the SR and Moose, seems
like with the extra range tanks with low fuel you could uncover the fuel
pick up on approach. I was considering going with a fore and aft pick up

as

some have done. However my tanks will be all sealed up (QB wing) when I

get

them.

After talking with Robin at MAM he said they tested it in all attitudes

and

had no problem, however that was with only a 40 gallon tank on one side

and

a 30 on the other. He said if he did his own he would consider a header
tank under the right seat floor. I think this may be a good idea. Looks
like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the header
tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or does

it

act like just a big piece of fuel line?

Thanks,
Scott
SR#174

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Hi Brian,

70 degrees! it was only 5 downtown this morning. Everything had been
melting off nicely at around 40, but it decided to cool off again.

Temperature in the engine compartment is something I'll have to look into.
I wouldn't expect it to be nearly as high with a water cooled engine as with
an air cooled engine, but it's definitely something to look into. I've got
years to figure that out though!

My tank idea is certainly an unknown consideration, and that's why I was
looking for comments, to ferret out potential problems. I also intend to
make some model ram air tubes and take them flying with a pressure gauge
attached to them... stick them out the window and see what kind of pressures
I get. I want to try a J tube with a hole drilled at the back of the J to
let water out specifically to see if it still creates adequate pressure.

I was also thinking or rigging up a miniature model of the whole tank system
and take it up in my ultralight and see if it will transfer at 50 mph. If
I'm not satisfied with the results of all this by the time I start building
the wings (still at least a year off I'm sure), then I'll probably do what
Warren has suggested and plumb them separately. I suppose the fuel
management won't increase that much since the whole idea is that the
outboard tanks won't be getting used very often anyway. On those occasions
when they are used, presumably it's going to be a big trip with heightened
diligence to details.

Mike
195SR

----- Original Message -----
From: "Brian Lawson" <lawsonb@mnsi.net>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 11:59 AM
Subject: Re: Moose Fuel Header Tank




Hey Mike,

Was there not some comment made recently about heating problems with
fire-wall mounted gascolators, to the point of mounting behind the
seats as an alternative? Would a fire-wall mounted header tank not be
more susceptible to heat than just the gascolator?

And further to header tank suggestions, I've recently seen a pair of
header tanks on a GlaStar (high wing gravity feed, as is the Rebel).
These were about 10 inches deep by about 4 inch diameter, but formed
into an oval shape, so the "diameter" was like 2" X 5". (This could
well have been a piece of "strut" tubing, with welded end caps and
fittings.) These each had three "ports". One was on the bottom and
fed the engine, one at the top is the feed from its wing-tank, and
the other one at the top I assume was a vent, but I could not see
where it "vented" to, and more interestingly how deep they reach into
the header tank. These were mounted to the cabin frame (the GlaStar
is a composite, but with a crash cage) just behind the seats at about
1/2 way between cabin roof and floor. Easy to see and service, and
occupies no "useful space" the way they are tucked in. Serves lots of
purposes I would think, not the least of which is nose down attitude
during approach with low fuel.

Just a comment, but isn't some of what you are suggesting with the
separate tanks a bit risky in the un-known, versus using fuel transfer
pumps?

Have a good one.

Brian Lawson
Windsor, Ontario.

ps...Just worked up a nice sweat cutting the grass which was getting
pretty long. It's pushing 70 degrees here today. Heh heh. Should we
be sending shovels or St. Bernards up your way?
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
On Thu, 11 Apr 2002 08:18:35 -0800, you wrote:

Hi Scott, I intend to use a header tank also, but mounted on the firewall.
I will be doing this though because of fuel injection on the Subaru. Using
fuel injection I need to have a return line, and it's much simpler to

return

to a header tank than to the wing tanks. Installations like this that I
have seen had no vent as the wing tanks just keep the header full.

Mike
195SR

----- Original Message -----
From: "Scott & Leere' Aldrich" <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 7:48 AM
Subject: Moose Fuel Header Tank

I have never liked the single fuel pick up used on the SR and Moose,

seems

like with the extra range tanks with low fuel you could uncover the fuel
pick up on approach. I was considering going with a fore and aft pick up

as

some have done. However my tanks will be all sealed up (QB wing) when I

get

them.

After talking with Robin at MAM he said they tested it in all attitudes

and

had no problem, however that was with only a 40 gallon tank on one side

and

a 30 on the other. He said if he did his own he would consider a header
tank under the right seat floor. I think this may be a good idea. Looks
like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the

header

tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or does

it

act like just a big piece of fuel line?

Thanks,
Scott
SR#174

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Scott,

If you use a header tank I believe it has to be vented back to one of the main tanks.
That's how my Kitfox is vented as per manual and it makes sense if you think about it.

There is no shut off valve before the 1 gal. header tank which is located behind the seat at the lowest point with a drain.

Bruce G 357R

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Mike, if I'm reading you right here it sounds like you are going to gravity
feed the header and then the pressurized "bypass", from the pump, will be
put back into this same header. I would be afraid that the pressurized fuel
going back into the non-vented header might stop or hinder the gravity flow
from the tanks, therefore you would need a vent line from the header back up
to the tank. Since I imagine the return line only needs to be 1/4" (that's
all it is on my UTVA's 340HP 15 psi pressure carbs) why not just run it back
up to the tanks and take the complications out of the system. Feed it back
into the cross vent line so it fills both tanks back up evenly, as that is
the only fault with the UTVA's as it feeds back into the left tank and when
flying at 60% power the right tank gets empty a lot quicker than the left
one!

Regards,
Wayne G. O'Shea
www.irishfield.on.ca

----- Original Message -----
From: "Mike Davis" <mike.davis@dcsol.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 12:18 PM
Subject: Re: Moose Fuel Header Tank

Hi Scott, I intend to use a header tank also, but mounted on the firewall.
I will be doing this though because of fuel injection on the Subaru.

Using

fuel injection I need to have a return line, and it's much simpler to

return

to a header tank than to the wing tanks. Installations like this that I
have seen had no vent as the wing tanks just keep the header full.

Mike
195SR

----- Original Message -----
From: "Scott & Leere' Aldrich" <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 7:48 AM
Subject: Moose Fuel Header Tank

I have never liked the single fuel pick up used on the SR and Moose,

seems

like with the extra range tanks with low fuel you could uncover the fuel
pick up on approach. I was considering going with a fore and aft pick

up

as

some have done. However my tanks will be all sealed up (QB wing) when I

get

them.

After talking with Robin at MAM he said they tested it in all attitudes

and

had no problem, however that was with only a 40 gallon tank on one side

and

a 30 on the other. He said if he did his own he would consider a header
tank under the right seat floor. I think this may be a good idea. Looks
like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the

header

tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or does

it

act like just a big piece of fuel line?

Thanks,
Scott
SR#174

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Hi Wayne,

You're reading it right, but I didn't see that as a problem... there will
never be as much fuel coming back from the high pressure system as has been
taken from the header tank to supply the high pressure system because the
engine will be using some of it. It seems to me that there should be a
fairly constant rate of fuel being returned from the spray bars, but since
it will always be less than what is being pumped out the gravity feed system
would supply the difference required to keep the header full. I had
imagined a tap on the top of the header tank with a hard line down to a
standard spring loaded drain mounted on the bottom of the firewall to remove
all the air during pre-flight, then it would be a closed system... the only
time you should ever get air in it again is if you managed to run a tank dry
and sucked air down into it. I would think if you ever pulled that much air
into the system the big fan would stop turning no matter how it was plumbed.
It would be nice if there was a valve like a shop vac has in it with a
floating ball that would close when the fuel was all the way to the top, but
open if you got air in there, then the air could escape to be replaced by
fuel.

Mike

----- Original Message -----
From: "Wayne G. O'Shea" <oifa@irishfield.on.ca>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 6:28 PM
Subject: Re: Moose Fuel Header Tank

Mike, if I'm reading you right here it sounds like you are going to

gravity

feed the header and then the pressurized "bypass", from the pump, will be
put back into this same header. I would be afraid that the pressurized

fuel

going back into the non-vented header might stop or hinder the gravity

flow

from the tanks, therefore you would need a vent line from the header back

up

to the tank. Since I imagine the return line only needs to be 1/4" (that's
all it is on my UTVA's 340HP 15 psi pressure carbs) why not just run it

back

up to the tanks and take the complications out of the system. Feed it back
into the cross vent line so it fills both tanks back up evenly, as that is
the only fault with the UTVA's as it feeds back into the left tank and

when

flying at 60% power the right tank gets empty a lot quicker than the left
one!

Regards,
Wayne G. O'Shea
www.irishfield.on.ca

----- Original Message -----
From: "Mike Davis" <mike.davis@dcsol.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 12:18 PM
Subject: Re: Moose Fuel Header Tank

Hi Scott, I intend to use a header tank also, but mounted on the

firewall.

I will be doing this though because of fuel injection on the Subaru.

Using

fuel injection I need to have a return line, and it's much simpler to

return

to a header tank than to the wing tanks. Installations like this that I
have seen had no vent as the wing tanks just keep the header full.

Mike
195SR

----- Original Message -----
From: "Scott & Leere' Aldrich" <flynski@peoplepc.com>
To: <murphy-rebel@dcsol.com>
Sent: Thursday, April 11, 2002 7:48 AM
Subject: Moose Fuel Header Tank

I have never liked the single fuel pick up used on the SR and Moose,

seems

like with the extra range tanks with low fuel you could uncover the

fuel

pick up on approach. I was considering going with a fore and aft pick

up

as

some have done. However my tanks will be all sealed up (QB wing) when

I

get

them.

After talking with Robin at MAM he said they tested it in all

attitudes

and

had no problem, however that was with only a 40 gallon tank on one

side

and

a 30 on the other. He said if he did his own he would consider a

header

tank under the right seat floor. I think this may be a good idea.

Looks

like there is room for a 1.5 or more gallon tank in there.

I have not found a lot of information on header tanks.

I plan on a L,R and Both valve. This would have to come before the

header

tank.

Question 1, would it be a good idea to have a shut off valve after the
header tank?

Question 2, is there any venting as far as the header tank goes, or

does

it

act like just a big piece of fuel line?

Thanks,
Scott
SR#174

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Hi

I spoke to Robin at MAM regarding fuel line routing. He brought up the point
of mounting the gascolator behind the seats to prevent vapour lock from a
hot engine. This may also be something to consider when mounting a header
tank.

Just a thought.

Murray Cherkas
REBEL 505




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Comments follow regarding several posts under the above subject.

I don't have the numbers here but I think 1 psi ram effect for a fuel
vent might be fairly optimistic. Any low pressure check valve is of
course subject to freezing even with a tiny drop of moisture.

There are header tanks flying that aren't vented however I made certain
mine is vented back to the cross tank vent line because I am expecting
vapour to be released as warm fuel is returned from the efi system. I
guess a gravity feed with a continuous downslope to the top of the
header might let bubbles make their way back to the tank but I didn't
want to risk it. Also I think you will find that pretty much all the efi
pumps have internal check valves. I used external check valves as well
but only because I'm using submersed pumps that are plumbed with rubber
hose inside the header tank that is a pain to inspect and that has been
known to fail on occasion.

Don't forget how often fuel mismanagement causes trouble. I really think
the goal here is simplicity. My system has no pilot management and a big
red light that comes on if the header tank is ever not full.

I have never heard of anyone succesfully returning efi fuel to the wing
tanks without a double valve that feeds and returns to the same tank. No
matter what you do, one tank will fill faster than the other. A valve
means management and expense traded off against your comfort level with
the location of a header tank. I kind of like the idea of a header tank
large enough for an approach and incapable of feeding a slug of air to
the pumps even if a main tank outlet is uncovered momentarily. I think
of it as a big sump and gascolator with a water drain. Efi systems don't
have a carbuerator bowl reservoir of course to protect against slugs of
air.

The other think is that I'm not sure a shutoff after the pump is really
necesary. THe check valve might stop gravity flow with the pumps off
especially if you have valves to the header already to eliminate the
head of fuel from the wing tanks.

Ken



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Hi Folks

If your aircraft is flying at say 140 mph, the ram air pressure is
approximately 0.34 psi. I can give you numbers at different speeds if you
are really interested.

Just a little trivia to make you think a bit.

Brian #328R

-----Original Message-----
From: murphy-rebel@dcsol.com [mailto:murphy-rebel@dcsol.com]On Behalf Of
klehman
Sent: Saturday, April 13, 2002 12:24 PM
To: murphy-rebel@dcsol.com
Subject: Re: Moose Fuel Header Tank


Comments follow regarding several posts under the above subject.

I don't have the numbers here but I think 1 psi ram effect for a fuel
vent might be fairly optimistic. Any low pressure check valve is of
course subject to freezing even with a tiny drop of moisture.

There are header tanks flying that aren't vented however I made certain
mine is vented back to the cross tank vent line because I am expecting
vapour to be released as warm fuel is returned from the efi system. I
guess a gravity feed with a continuous downslope to the top of the
header might let bubbles make their way back to the tank but I didn't
want to risk it. Also I think you will find that pretty much all the efi
pumps have internal check valves. I used external check valves as well
but only because I'm using submersed pumps that are plumbed with rubber
hose inside the header tank that is a pain to inspect and that has been
known to fail on occasion.

Don't forget how often fuel mismanagement causes trouble. I really think
the goal here is simplicity. My system has no pilot management and a big
red light that comes on if the header tank is ever not full.

I have never heard of anyone succesfully returning efi fuel to the wing
tanks without a double valve that feeds and returns to the same tank. No
matter what you do, one tank will fill faster than the other. A valve
means management and expense traded off against your comfort level with
the location of a header tank. I kind of like the idea of a header tank
large enough for an approach and incapable of feeding a slug of air to
the pumps even if a main tank outlet is uncovered momentarily. I think
of it as a big sump and gascolator with a water drain. Efi systems don't
have a carbuerator bowl reservoir of course to protect against slugs of
air.

The other think is that I'm not sure a shutoff after the pump is really
necesary. THe check valve might stop gravity flow with the pumps off
especially if you have valves to the header already to eliminate the
head of fuel from the wing tanks.

Ken

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