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glastar(at)gmx.net
Guest

Posted: Thu Oct 14, 2010 12:36 pm Post subject: fuel valve with position both

I might open Pandoras box here but it's not about primer so lets try:



On my high wing Glastar I have a left/both/right fuel valve and it is 

used most of the time in the both mode, except when on the ground 

(crossfeed risk) or on low fuel situations.



Now on low wing airplanes I see the left/right only, what is the reason 

for it (I guess there must be a technical reason behind that)?



ok I get my firesuite out before I get the flames



Werner

pitts_pilot(at)bellsouth.
Guest

Posted: Thu Oct 14, 2010 12:48 pm Post subject: fuel valve with position both

No flames.  Actually, it's a good question.

On the high wing, the valve is always under positive fuel pressure (in 

any attitude but inverted ....  ) due to the head .... 5' maybe?

On the low wing, it would be possible to unport one tank feed ..... and 

suck air.

Linn



On 10/14/2010 4:32 PM, Werner Schneider wrote:

 	  Quote: 	
		   



 I might open Pandoras box here but it's not about primer so lets try:



 On my high wing Glastar I have a left/both/right fuel valve and it is 

 used most of the time in the both mode, except when on the ground 

 (crossfeed risk) or on low fuel situations.



 Now on low wing airplanes I see the left/right only, what is the 

 reason for it (I guess there must be a technical reason behind that)?



 ok I get my firesuite out before I get the flames



 Werner

bruce1hwjohnson(at)yahoo.
Guest

Posted: Thu Oct 14, 2010 12:57 pm Post subject: fuel valve with position both

IM not sure why, but I miss that option.

   From: Werner Schneider <glastar(at)gmx.net>

To: rv10-list(at)matronics.com

Sent: Thu, October 14, 2010 1:32:34 PM

Subject: fuel valve with position both

--> RV10-List message posted by: Werner Schneider <glastar(at)gmx.net (glastar(at)gmx.net)>

I might open Pandoras box here but it's not about primer so lets try:

On my high wing Glastar I have a left/both/right fuel valve and it is used most of the time in the both mode, except when on the ground (crossfeed risk) or on low fuel situations.

Now on low wing airplanes I see the left/right only, what is the reason for it (I guess there must be a technical reason behind that)?

ok I get my firesuite out before I nbsp;                        &nbs===================

               [quote][b]

glastar(at)gmx.net
Guest

Posted: Fri Oct 15, 2010 3:35 am Post subject: fuel valve with position both

Thanks Linn,



I agree, on a high wing the fuel pressure is higher, but on a low wing 

you still pressurize the tanks as well so you should be fine? Unporting 

would only be possible on a very low fuel level or uncoordinated flight

I plan to add low fuel warnings as well (have them in my Star as we have 

a SB concerning the same problem).



Will see if we get deeper into that "why".



Cheers Werner



Glastar HB-YKP flying

RV-10 #41122 waiting for shipping

On 14.10.2010 22:45, Linn Walters wrote:

 	  Quote: 	
		   



 No flames. Actually, it's a good question.

 On the high wing, the valve is always under positive fuel pressure (in

 any attitude but inverted ....  ) due to the head .... 5' maybe?

 On the low wing, it would be possible to unport one tank feed ..... and

 suck air.

 Linn



 On 10/14/2010 4:32 PM, Werner Schneider wrote:

> 

>

> I might open Pandoras box here but it's not about primer so lets try:

>

> On my high wing Glastar I have a left/both/right fuel valve and it is

> used most of the time in the both mode, except when on the ground

> (crossfeed risk) or on low fuel situations.

>

> Now on low wing airplanes I see the left/right only, what is the

> reason for it (I guess there must be a technical reason behind that)?

>

> ok I get my firesuite out before I get the flames

>

> Werner

pitts_pilot(at)bellsouth.
Guest

Posted: Fri Oct 15, 2010 3:47 am Post subject: fuel valve with position both

On 10/15/2010 7:31 AM, Werner Schneider wrote:

 	  Quote: 	
		   



 Thanks Linn,



 I agree, on a high wing the fuel pressure is higher, but on a low wing 

 you still pressurize the tanks as well so you should be fine? 

 Unporting would only be possible on a very low fuel level or 

 uncoordinated flight

 I plan to add low fuel warnings as well (have them in my Star as we 

 have a SB concerning the same problem).



 Will see if we get deeper into that "why".

Well, you already did!!
	


I'm not sure how much 'usable fuel' you will get ...... the valve is 

mounted at the top of the tunnel ..... run that station out to the wing 

tank and see how much fuel you leave in the tank.  Better to just take a 

pass on the 'both' valve.

Linn



 	  Quote: 	
		  

 Cheers Werner



 Glastar HB-YKP flying

 RV-10 #41122 waiting for shipping

 On 14.10.2010 22:45, Linn Walters wrote:

> 

> <pitts_pilot(at)bellsouth.net>

>

> No flames. Actually, it's a good question.

> On the high wing, the valve is always under positive fuel pressure (in

> any attitude but inverted ....  ) due to the head .... 5' maybe?

> On the low wing, it would be possible to unport one tank feed ..... and

> suck air.

> Linn

>

> On 10/14/2010 4:32 PM, Werner Schneider wrote:

>> 

>>

>> I might open Pandoras box here but it's not about primer so lets try:

>>

>> On my high wing Glastar I have a left/both/right fuel valve and it is

>> used most of the time in the both mode, except when on the ground

>> (crossfeed risk) or on low fuel situations.

>>

>> Now on low wing airplanes I see the left/right only, what is the

>> reason for it (I guess there must be a technical reason behind that)?

>>

>> ok I get my firesuite out before I get the flames

>>

>> Werner

>>

>>

>>

>>

>>

>>

>

glastar(at)gmx.net
Guest

Posted: Fri Oct 15, 2010 4:40 am Post subject: fuel valve with position both

Hello Linn,



no, my valve will be on the bottom of the tunnel (Andair Valve with 

extension) and I have still the head pressure of the tank vents.



As I have still time until I'm there I will do a bit of geometry to see 

where I end.



Thanks



Werner



Glastar HB-YKP flying

RV-10 #41122 waiting for shipping



On 15.10.2010 13:44, Linn Walters wrote:

 	  Quote: 	
		   



 On 10/15/2010 7:31 AM, Werner Schneider wrote:

> 

>

> Thanks Linn,

>

> I agree, on a high wing the fuel pressure is higher, but on a low wing

> you still pressurize the tanks as well so you should be fine?

> Unporting would only be possible on a very low fuel level or

> uncoordinated flight

> I plan to add low fuel warnings as well (have them in my Star as we

> have a SB concerning the same problem).

>

> Will see if we get deeper into that "why".

 Well, you already did!!

 I'm not sure how much 'usable fuel' you will get ...... the valve is

 mounted at the top of the tunnel ..... run that station out to the wing

 tank and see how much fuel you leave in the tank. Better to just take a

 pass on the 'both' valve.

 Linn



>

> Cheers Werner

>

> Glastar HB-YKP flying

> RV-10 #41122 waiting for shipping

> On 14.10.2010 22:45, Linn Walters wrote:

>> 

>> <pitts_pilot(at)bellsouth.net>

>>

>> No flames. Actually, it's a good question.

>> On the high wing, the valve is always under positive fuel pressure (in

>> any attitude but inverted ....  ) due to the head .... 5' maybe?

>> On the low wing, it would be possible to unport one tank feed ..... and

>> suck air.

>> Linn

>>

>> On 10/14/2010 4:32 PM, Werner Schneider wrote:

>>> 

>>>

>>> I might open Pandoras box here but it's not about primer so lets try:

>>>

>>> On my high wing Glastar I have a left/both/right fuel valve and it is

>>> used most of the time in the both mode, except when on the ground

>>> (crossfeed risk) or on low fuel situations.

>>>

>>> Now on low wing airplanes I see the left/right only, what is the

>>> reason for it (I guess there must be a technical reason behind that)?

>>>

>>> ok I get my firesuite out before I get the flames

>>>

>>> Werner

>>>

>>>

>>>

>>>

>>>

>>>

>>

>>

>>

>>

>>

>>

>>

>

kevino

Joined: 21 Sep 2010
Posts: 13
Location: United States

Posted: Fri Oct 15, 2010 5:26 am Post subject: Re: fuel valve with position both

I have some experience on this topic. During phase 1 testing on my 10 i ran a tank dry over airport and had an engine failure. Was unable to get other tank on line due to air in system. Dead stick landing. no issues. discovered that the vans fuel valve which was left, right and aux was allowing the good tank to still draw air due to being slighty out of the detent position. lousy detent on vans valves. replaced valve with andair. no further issues. not a fan of cheap valves on low wing airplanes. you cannot use a valve with both on low wing.

Kevin

dave.saylor.aircrafters(a
Guest

Posted: Fri Oct 15, 2010 6:15 am Post subject: fuel valve with position both

Werner,



The head pressure from your Glastar tanks is many times the pressure

from the fuel vent.  If it weren't, high-wings on "Both" would be

running out of gas all the time.



Head pressure tries to push fuel back into the empty tank, against

vent pressure.  That works in a high-wing because you have a couple

feet of rise.  In a low-wing airplane there isn't enough pressure

difference between an empty tank and a partially-full tank to favor

the fuller tank.  The pump pulls from the path of least resistance,

which is the air in the empty tank.  Lots of people have tried a

"Both"position in RVs and other low wings.  It doesn't work out.



You'll build a safer plane if you stick with Left-Right-Off.  I didn't

have much low-wing time before my 10 and while it is something else to

do, switching back and forth isn't that big a deal.  Plus it really

keeps you cognizant of your fuel situation.



Dave Saylor

AirCrafters

140 Aviation Way

Watsonville, CA 95076

831-722-9141 Shop

831-750-0284 Cell



On Fri, Oct 15, 2010 at 5:36 AM, Werner Schneider <glastar(at)gmx.net> wrote:

 	  Quote: 	
		   



 Hello Linn,



 no, my valve will be on the bottom of the tunnel (Andair Valve with

 extension) and I have still the head pressure of the tank vents.



 As I have still time until I'm there I will do a bit of geometry to see

 where I end.



 Thanks



 Werner



 Glastar HB-YKP flying

 RV-10 #41122 waiting for shipping



 On 15.10.2010 13:44, Linn Walters wrote:

>

> 

>

> On 10/15/2010 7:31 AM, Werner Schneider wrote:

>>

>> 

>>

>> Thanks Linn,

>>

>> I agree, on a high wing the fuel pressure is higher, but on a low wing

>> you still pressurize the tanks as well so you should be fine?

>> Unporting would only be possible on a very low fuel level or

>> uncoordinated flight

>> I plan to add low fuel warnings as well (have them in my Star as we

>> have a SB concerning the same problem).

>>

>> Will see if we get deeper into that "why".

>

> Well, you already did!!

> I'm not sure how much 'usable fuel' you will get ...... the valve is

> mounted at the top of the tunnel ..... run that station out to the wing

> tank and see how much fuel you leave in the tank. Better to just take a

> pass on the 'both' valve.

> Linn

>

>>

>> Cheers Werner

>>

>> Glastar HB-YKP flying

>> RV-10 #41122 waiting for shipping

>>

>>

>> On 14.10.2010 22:45, Linn Walters wrote:

>>>

>>> 

>>> <pitts_pilot(at)bellsouth.net>

>>>

>>> No flames. Actually, it's a good question.

>>> On the high wing, the valve is always under positive fuel pressure (in

>>> any attitude but inverted ....  ) due to the head .... 5' maybe?

>>> On the low wing, it would be possible to unport one tank feed ..... and

>>> suck air.

>>> Linn

>>>

>>> On 10/14/2010 4:32 PM, Werner Schneider wrote:

>>>>

>>>> 

>>>>

>>>> I might open Pandoras box here but it's not about primer so lets try:

>>>>

>>>> On my high wing Glastar I have a left/both/right fuel valve and it is

>>>> used most of the time in the both mode, except when on the ground

>>>> (crossfeed risk) or on low fuel situations.

>>>>

>>>> Now on low wing airplanes I see the left/right only, what is the

>>>> reason for it (I guess there must be a technical reason behind that)?

>>>>

>>>> ok I get my firesuite out before I get the flames

>>>>

>>>> Werner

>>>>

>>>>

>>>>

>>>>

>>>>

>>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>>

>>

>>

>>

>>

>>

Tim Olson

Joined: 25 Jan 2007
Posts: 2872

Posted: Fri Oct 15, 2010 7:50 am Post subject: fuel valve with position both

Also, a side "benefit" to the low wing's limitation against "both" position is that it reinforces better fuel management practices....and allows you to always know the remaining fuel. 

Anybody notice that the rv-10's with presumably nearly 100% equipage of fuel computers and flow meters, has basically never had an off-airport landing (that we know of) due to poor fuel planning?  Let's keep it that way....we have the tools, if we use them.

Tim

On Oct 15, 2010, at 4:31 AM, Werner Schneider <glastar(at)gmx.net> wrote:

 	  Quote: 	

 Thanks Linn,

 I agree, on a high wing the fuel pressure is higher, but on a low wing you still pressurize the tanks as well so you should be fine? Unporting would only be possible on a very low fuel level or uncoordinated flight

 I plan to add low fuel warnings as well (have them in my Star as we have a SB concerning the same problem).

 Will see if we get deeper into that "why".

 Cheers Werner

 Glastar HB-YKP flying

 RV-10 #41122 waiting for shipping

 On 14.10.2010 22:45, Linn Walters wrote:

> 

> 

> No flames. Actually, it's a good question.

> On the high wing, the valve is always under positive fuel pressure (in

> any attitude but inverted ....  ) due to the head .... 5' maybe?

> On the low wing, it would be possible to unport one tank feed ..... and

> suck air.

> Linn

> 

> On 10/14/2010 4:32 PM, Werner Schneider wrote:

>> 

>> 

>> I might open Pandoras box here but it's not about primer so lets try:

>> 

>> On my high wing Glastar I have a left/both/right fuel valve and it is

>> used most of the time in the both mode, except when on the ground

>> (crossfeed risk) or on low fuel situations.

>> 

>> Now on low wing airplanes I see the left/right only, what is the

>> reason for it (I guess there must be a technical reason behind that)?

>> 

>> ok I get my firesuite out before I get the flames

>> 

>> Werner

>> 

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

> 

> 

>

stein(at)steinair.com
Guest

Posted: Fri Oct 15, 2010 8:34 am Post subject: fuel valve with position both

It is possible to have a "both" fuel system, but in low wing planes as

others have said it's difficult because the fuel is at/near/below the

engine.  While at rest gravity would naturally keep the tank levels

balanced, in the air it's a different story.  It's not just about the tanks

being pressurized/vented, but for a "both" selection they need to be

pressurized equally.  You'll notice that in most high wing airplanes with a

both selection, the vents of the two tanks are tied together...in a low wing

plane if you didn't have the two tank vents tied together, then one tank

will likely have a slightly higher pressure than the other...which mean fuel

will be routed from that particular tank and possibly run empty before

sucking gas out of the other tank; and you could have an engine sucking air

with one wing tank being completely full.  It could also cause fuel from one

tank to be routed to the other and then overboard.  Even though the tanks

are vented and "pressurized", it's likely not enough to cause sufficient

fuel flow to the engine without and electric or fuel driven pump (which you

can get by without on many high wing planes). Remember, we're as much

"sucking" the fuel from the tanks as we are pushing when the level of the

tanks is below the engine.  



Anyway, There are ways to do it but none as simple as just doing it the way

Van's says.  There have been various people who've re-invented the wheel on

van's fuel system, but out of the 7000+ flying RV's, the standard way of

doing it has been proven as reliable and functional.



My 2 cents as usual!



Cheers,  



Stein 



--

kevino

Joined: 21 Sep 2010
Posts: 13
Location: United States

Posted: Fri Oct 15, 2010 9:35 am Post subject: Re: fuel valve with position both

One other point. I dont have it with me but believe the manual on the air flow performance fuel pump has a specific warning on introducing air into the system could cause an air lock.

Kevin

pilotmelch(at)omnav.com
Guest

Posted: Fri Oct 15, 2010 10:07 am Post subject: fuel valve with position both

This can be simply explained with an analogy.



Picture yourself with two glasses of beer above your head, with a tube

coming out the bottom of both running to a Y and a single tube then running

into your mouth.  Once you start sucking a little, you'd get some beer, and

wouldn't need to suck much more after that (or at all).  Essentially both

glasses are gravity feeding the single tube, and until they both run empty

you'll get a constant flow of beer.



Now do the same thing, but put the glasses down to your knees.  Nothing is

automatically filling the single tube after the Y.  In fact, gravity will

attempt to equalize the amount in each glass so their levels remain the

same, but gravity can't fill the tube running up to your mouth higher than

the top level in the glasses down at your knees.  You must suck, and

continue to do so to get beer.  The further from your mouth, the harder

you'll need to suck.  If you get ahead of gravity's ability to even the

glasses, and you empty one of them ahead of the other, your required sucking

will suck air (likely a mix of mostly air and some beer).  Either way, your

required constant flow of beer has been interrupted and that's bad.



John Melchert

N316PT RV-10 (building, QB fuse)

Eden Prairie, MN

robin(at)PaintTheWeb.com
Guest

Posted: Fri Oct 15, 2010 10:25 am Post subject: fuel valve with position both

I am grabbing 4 beers and trying this now!



Burp,

Do Not Archive



--

dave.saylor.aircrafters(a
Guest

Posted: Fri Oct 15, 2010 12:17 pm Post subject: fuel valve with position both

 	  Quote: 	
		   required constant flow of beer has been interrupted<<


	


And I thought running out of gas was bad...that's just unthinkable.



Do Not Archive



Dave Saylor

AirCrafters

140 Aviation Way

Watsonville, CA 95076

831-722-9141 Shop

831-750-0284 Cell



On Fri, Oct 15, 2010 at 11:04 AM, John Melchert <pilotmelch(at)omnav.com> wrote:

 	  Quote: 	
		   



 This can be simply explained with an analogy.



 Picture yourself with two glasses of beer above your head, with a tube

 coming out the bottom of both running to a Y and a single tube then running

 into your mouth. Â Once you start sucking a little, you'd get some beer, and

 wouldn't need to suck much more after that (or at all). Â Essentially both

 glasses are gravity feeding the single tube, and until they both run empty

 you'll get a constant flow of beer.



 Now do the same thing, but put the glasses down to your knees. Â Nothing is

 automatically filling the single tube after the Y. Â In fact, gravity will

 attempt to equalize the amount in each glass so their levels remain the

 same, but gravity can't fill the tube running up to your mouth higher than

 the top level in the glasses down at your knees. Â You must suck, and

 continue to do so to get beer. Â The further from your mouth, the harder

 you'll need to suck. Â If you get ahead of gravity's ability to even the

 glasses, and you empty one of them ahead of the other, your required sucking

 will suck air (likely a mix of mostly air and some beer). Â Either way, your

 required constant flow of beer has been interrupted and that's bad.



 John Melchert

 N316PT RV-10 (building, QB fuse)

 Eden Prairie, MN

rv10(at)colohan.com
Guest

Posted: Fri Oct 15, 2010 12:39 pm Post subject: fuel valve with position both

I've not played with the combination of beer and hoses since college -- but in my experience, when you run beer through a funnel and tube, you can get all sorts of vapor lock problems with excessive foaming, no matter if you use gravity or suck it uphill. 



Perhaps you can avoid these problems by only using fuel that doesn't contain alcohol?  

Chris



On Fri, Oct 15, 2010 at 11:04 AM, John Melchert <pilotmelch(at)omnav.com (pilotmelch(at)omnav.com)> wrote:

 [quote]--> RV10-List message posted by: "John Melchert" <pilotmelch(at)omnav.com (pilotmelch(at)omnav.com)>

  

 This can be simply explained with an analogy.

 

 Picture yourself with two glasses of beer above your head, with a tube

 coming out the bottom of both running to a Y and a single tube then running

 into your mouth.  Once you start sucking a little, you'd get some beer, and

 wouldn't need to suck much more after that (or at all).  Essentially both

 glasses are gravity feeding the single tube, and until they both run empty

 you'll get a constant flow of beer.

 

 Now do the same thing, but put the glasses down to your knees.  Nothing is

 automatically filling the single tube after the Y.  In fact, gravity will

 attempt to equalize the amount in each glass so their levels remain the

 same, but gravity can't fill the tube running up to your mouth higher than

 the top level in the glasses down at your knees.  You must suck, and

 continue to do so to get beer.  The further from your mouth, the harder

 you'll need to suck.  If you get ahead of gravity's ability to even the

 glasses, and you empty one of them ahead of the other, your required sucking

 will suck air (likely a mix of mostly air and some beer).  Either way, your

 required constant flow of beer has been interrupted and that's bad.

 

 John Melchert

 N316PT RV-10 (building, QB fuse)

 Eden Prairie, MN

 



 

 

 ===========

 arget="_blank">http://www.matronics.com/Navigator?RV10-List

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ===========

 

 

 

 



[b]

glastar(at)gmx.net
Guest

Posted: Fri Oct 15, 2010 1:02 pm Post subject: fuel valve with position both

Many thanks for the many and valuable comments.



A both position would work, if each tank would have a single fuel pump 

before the fuel valve in the cases described, this would grant a fuel 

flow secured after unporting and switching valve.



I agree left right demands a constant fuel management (which puts more 

load in difficult situation) but makes a bigger awareness of fuel remaining.



A lot of fuel (or beer) for thoughts and good technical arguments.



Thanks again to the group for filling that gap of my missing knowledge.



I probably will go the Andair fuel pump way as it looks to be the better 

technology with much less connections then the ES Airflow one.



br



Werner



Glastar HB-YKP flying

RV-10 #41122 waiting for shipping



On 15.10.2010 18:24, Stein Bruch wrote:

 	  Quote: 	
		   



 It is possible to have a "both" fuel system, but in low wing planes as

 others have said it's difficult because the fuel is at/near/below the

 engine.  While at rest gravity would naturally keep the tank levels

 balanced, in the air it's a different story.  It's not just about the tanks

 being pressurized/vented, but for a "both" selection they need to be

 pressurized equally.  You'll notice that in most high wing airplanes with a

 both selection, the vents of the two tanks are tied together...in a low wing

 plane if you didn't have the two tank vents tied together, then one tank

 will likely have a slightly higher pressure than the other...which mean fuel

 will be routed from that particular tank and possibly run empty before

 sucking gas out of the other tank; and you could have an engine sucking air

 with one wing tank being completely full.  It could also cause fuel from one

 tank to be routed to the other and then overboard.  Even though the tanks

 are vented and "pressurized", it's likely not enough to cause sufficient

 fuel flow to the engine without and electric or fuel driven pump (which you

 can get by without on many high wing planes). Remember, we're as much

 "sucking" the fuel from the tanks as we are pushing when the level of the

 tanks is below the engine.



 Anyway, There are ways to do it but none as simple as just doing it the way

 Van's says.  There have been various people who've re-invented the wheel on

 van's fuel system, but out of the 7000+ flying RV's, the standard way of

 doing it has been proven as reliable and functional.



 My 2 cents as usual!



 Cheers,



 Stein

pitts_pilot(at)bellsouth.
Guest

Posted: Fri Oct 15, 2010 1:26 pm Post subject: fuel valve with position both

On 10/15/2010 4:55 PM, Werner Schneider wrote:

 	  Quote: 	
		   



 Many thanks for the many and valuable comments.

You're welcome.  It's why we're here.
	


 	  Quote: 	
		   A both position would work, if each tank would have a single fuel pump 

 before the fuel valve in the cases described, this would grant a fuel 

 flow secured after unporting and switching valve.

I see what you mean.  Having a pump (actually two) in the wing root at 
	


the lowest point would solve the problem that didn't exist before the 

'both' position was selected.  However, now we've added two pumps 

(weight), wire (weight) and switches (more weight) to solve a problem 

that really shouldn't exist.

 	  Quote: 	
		  

 I agree left right demands a constant fuel management (which puts more 

 load in difficult situation) but makes a bigger awareness of fuel 

 remaining.

As I see it, switching tanks every 15 minutes to 1/2 hour is a whole lot 
	


safer than turning on the pumps.  However, if you'll forget to switch 

tanks ...... maybe the switches will end up in the same category.  From 

experience, I can tell you that running a tank dry on takeoff (doing 

T&Gs) in the pattern will get your attention.  That was when I was a 

baby pilot.  Another educational experience.

 	  Quote: 	
		  

 A lot of fuel (or beer) for thoughts and good technical arguments.

I noticed that there are a lot of beer experts on this list. 
	


 	  Quote: 	
		   Thanks again to the group for filling that gap of my missing knowledge.

If we really did.
	


 	  Quote: 	
		   I probably will go the Andair fuel pump way as it looks to be the 

 better technology with much less connections then the ES Airflow one.

Not sure what that means. 
	


Best of luck.

Linn



 	  Quote: 	
		  

 br



 Werner



 Glastar HB-YKP flying

 RV-10 #41122 waiting for shipping



 On 15.10.2010 18:24, Stein Bruch wrote:

> 

>

> It is possible to have a "both" fuel system, but in low wing planes as

> others have said it's difficult because the fuel is at/near/below the

> engine.  While at rest gravity would naturally keep the tank levels

> balanced, in the air it's a different story.  It's not just about the 

> tanks

> being pressurized/vented, but for a "both" selection they need to be

> pressurized equally.  You'll notice that in most high wing airplanes 

> with a

> both selection, the vents of the two tanks are tied together...in a 

> low wing

> plane if you didn't have the two tank vents tied together, then one tank

> will likely have a slightly higher pressure than the other...which 

> mean fuel

> will be routed from that particular tank and possibly run empty before

> sucking gas out of the other tank; and you could have an engine 

> sucking air

> with one wing tank being completely full.  It could also cause fuel 

> from one

> tank to be routed to the other and then overboard.  Even though the 

> tanks

> are vented and "pressurized", it's likely not enough to cause sufficient

> fuel flow to the engine without and electric or fuel driven pump 

> (which you

> can get by without on many high wing planes). Remember, we're as much

> "sucking" the fuel from the tanks as we are pushing when the level of 

> the

> tanks is below the engine.

>

> Anyway, There are ways to do it but none as simple as just doing it 

> the way

> Van's says.  There have been various people who've re-invented the 

> wheel on

> van's fuel system, but out of the 7000+ flying RV's, the standard way of

> doing it has been proven as reliable and functional.

>

> My 2 cents as usual!

>

> Cheers,

>

> Stein

>

Jim Combs

Joined: 24 Jan 2010
Posts: 140
Location: Lexington, Ky

Posted: Tue Oct 19, 2010 3:50 pm Post subject: fuel valve with position both

Here is my solution to the "hard to feel detent" on the Vans fuel selector.  I made two stops using tubing and countersunk screws.  Now the fuel is easily positioned from one fuel tank to the other even in the dark.

 

Jim Combs - N312F

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RV-10 -> N312F - Flying as of 12/2008

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Tue Oct 19, 2010 5:26 pm Post subject: Re: fuel valve with position both

If the fuel line ruptures up in the engine area, how do you turn the fuel off? Try to feel between the detents?



As many do not know, starting about 2 and a half years ago, Vans began sending a different fuel valve arrangement out with kits. There is now a spring loaded, lift-to-turn, handle with positive detents. IMHO it also looks a whole lot nicer than the old handle.

_________________
Bob Turner
RV-10 QB

speckter(at)comcast.net
Guest

Posted: Wed Oct 20, 2010 4:53 am Post subject: fuel valve with position both

Jim, how do you turn off the fuel in an emergency?  

   

Gary Specketer  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jim Combs

 Sent: Tuesday, October 19, 2010 7:47 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Re: fuel valve with position both  

  

   

Here is my solution to the "hard to feel detent" on the Vans fuel selector.  I made two stops using tubing and countersunk screws.  Now the fuel is easily positioned from one fuel tank to the other even in the dark.

 

 Jim Combs - N312F

 

   

        [quote][b]

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