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dsmithlib

Joined: 06 Jul 2013
Posts: 2
Location: Libertyville, IL

Posted: Sat Aug 03, 2013 6:29 pm Post subject: Need explanation of fuel system w/dual 5gal pickups

I am rebuilding a Firestar II project.  It has two 5 gal tanks, I have the plans from the mid-90's and (I thought) I had a pretty good understanding of aviation fuel systems and venting.



However, I am seeing both tanks fed together to a T and then up to the pump or primer etc..   What I am missing is how the fuel is drawn from the tanks equally.  It seems to me that once air is introduced to EITHER fuel pickup, the system will be fuel starved.  



I realize there is something I am not picking up from the drawings.  I do not see any depiction of the venting which may hold the key.  In any event, I would appreciate a few comments on best practices for plumbing the two standard 5 gal tanks.



Thanks,

Dave

_________________
Dave Smith
RV7 Flying
Kolb Firestar II (in-progress)

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Sun Aug 04, 2013 2:06 am Post subject: Need explanation of fuel system w/dual 5gal pickups

 	  Quote: 	
		   It seems to me that once air is introduced to EITHER fuel pickup, the

system will be fuel starved. 
	




Are the tanks at the same level?



Are the pickups descending from a fitting at the bottom of the tanks, or do

they drop down into the tanks from above?



If the tanks are level, then when you suck air both tanks will be almost

completely empty.



In the case where the tanks are not level, if the pickups descend from a

bottom fitting the weight of the fuel will displace the air  potentially

introduced from the empty tank, and the fuel line will have fuel in it.



I have no experience with what I'm talking about here, I was just

visualizing the situation. I probably have misunderstood you cuz I imagine

you have already thought of all this.

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

racerjerry

Joined: 15 Dec 2009
Posts: 202
Location: Deer Park, NY

Posted: Sun Aug 04, 2013 3:13 am Post subject: Re: Need explanation of fuel system w/dual 5gal pickups

If you are feeding fuel from fittings attached to the bottom of each tank; and both tanks are vented and at the same level, then gravity will do a good job of evenly emptying both tanks.  I didnâ€™t care much for drilling holes in the bottom of the tanks, so I opted to feed fuel from the top of each tank.



If you are feeding fuel sucking from the top of each tank, then things are a bit different.  Fuel flow here is more dependent on venting pressures for each tank to empty evenly.  You are correct in that if one tank sucks air, itâ€™s GAME OVER.  I had one forced landing because of this and attributed it to a small pressure difference between the tank vents (they are located fore and aft in a â€˜breezyâ€™ spot behind the pilot/passenger) where most likely each vent was subjected to different airflow patterns.  There was only a small amount of fuel left in the other tank; so the system worked OK as long as neither one got too low.  You might try tying both vents together to equalize any pressure differences; but just donâ€™t let the fuel level get too low and you wonâ€™t have to worry about it.

_________________
Jerry King

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Sun Aug 04, 2013 4:08 am Post subject: Need explanation of fuel system w/dual 5gal pickups

Dave, I battled this one on my Mk III. My solution was to use a modified Weatherhead valve to get left, right, both, and off so I could control the tanks.The modification is simple. The Weatherhead valve has a nylon ball with two passages at right angles that meet in the center. There are four detents that control how the passages line up with the ports. Simply drill through one side so that there are now three passages in a "T" configuration. Which one of the original two you use to guide the drill is only dependent on where you want the handle to be when the the undrilled side of the ball is over the fuel inlet port (where you want the handle when the valve is in the OFF position.

 With this solution you have absolute control over how fuel is drawn from the tanks. On a cross country flight when I was running low on fuel and needed every available drop I was able to purposely run a tank dry and switch to the tank that still had fuel before the engine died. Having a Facet pump to boost fuel to the Mikuni pneumatic pump I got an instant prime when I switched tanks and the engine hardly stuttered before it had fuel from the other tank and resumed running.

 Yep, bad practice that I pulled off once and never repeated. The fact that I could do it at all was because the valve gave me complete control over the fuel supply.

Rick Girard

do not archive

 

On Sat, Aug 3, 2013 at 9:29 PM, dsmithlib <dsmithlib(at)ameritech.net (dsmithlib(at)ameritech.net)> wrote:

  	  Quote: 	
		  --> Kolb-List message posted by: "dsmithlib" <dsmithlib(at)ameritech.net (dsmithlib(at)ameritech.net)>

  

 I am rebuilding a Firestar II project.  It has two 5 gal tanks, I have the plans from the mid-90's and (I thought) I had a pretty good understanding of aviation fuel systems and venting.

 

 However, I am seeing both tanks fed together to a T and then up to the pump or primer etc..   What I am missing is how the fuel is drawn from the tanks equally.  It seems to me that once air is introduced to EITHER fuel pickup, the system will be fuel starved.

  

 I realize there is something I am not picking up from the drawings.  I do not see any depiction of the venting which may hold the key.  In any event, I would appreciate a few comments on best practices for plumbing the two standard 5 gal tanks.

  

 Thanks,

 Dave

 

 --------

 Dave Smith

 RV7 Flying

 Kolb Firestar II (in-progress)

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=405880#405880

 

 

 

 

 

 

 

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

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 http://forums.matronics.com

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 le, List Admin.

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

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-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

_________________
The smallest miracle right in front of you is enough to make you happy....

frank goodnight

Joined: 27 Dec 2011
Posts: 126

Posted: Sun Aug 04, 2013 4:45 am Post subject: Need explanation of fuel system w/dual 5gal pickups

Richard

What is weather head valve?

Where can I get one?

How can I be sure it is good for

Fuel?

Thanks

Frank 

Sent from my iPhone

On Aug 4, 2013, at 7:07 AM, Richard Girard <aslsa.rng(at)gmail.com> wrote:

[quote] Dave, I battled this one on my Mk III. My solution was to use a modified Weatherhead valve to get left, right, both, and off so I could control the tanks.

 The modification is simple. The Weatherhead valve has a nylon ball with two passages at right angles that meet in the center. There are four detents that control how the passages line up with the ports. Simply drill through one side so that there are now three passages in a "T" configuration. Which one of the original two you use to guide the drill is only dependent on where you want the handle to be when the the undrilled side of the ball is over the fuel inlet port (where you want the handle when the valve is in the OFF position.

 With this solution you have absolute control over how fuel is drawn from the tanks. On a cross country flight when I was running low on fuel and needed every available drop I was able to purposely run a tank dry and switch to the tank that still had fuel before the engine died. Having a Facet pump to boost fuel to the Mikuni pneumatic pump I got an instant prime when I switched tanks and the engine hardly stuttered before it had fuel from the other tank and resumed running.

 Yep, bad practice that I pulled off once and never repeated. The fact that I could do it at all was because the valve gave me complete control over the fuel supply.

 Rick Girard

 do not archive

 On Sat, Aug 3, 2013 at 9:29 PM, dsmithlib <dsmithlib(at)ameritech.net> wrote:

> 

> 

> I am rebuilding a Firestar II project.  It has two 5 gal tanks, I have the plans from the mid-90's and (I thought) I had a pretty good understanding of aviation fuel systems and venting.

> 

> However, I am seeing both tanks fed together to a T and then up to the pump or primer etc..   What I am missing is how the fuel is drawn from the tanks equally.  It seems to me that once air is introduced to EITHER fuel pickup, the system will be fuel starved.

> 

> I realize there is something I am not picking up from the drawings.  I do not see any depiction of the venting which may hold the key.  In any event, I would appreciate a few comments on best practices for plumbing the two standard 5 gal tanks.

> 

> Thanks,

> Dave

> 

> --------

> Dave Smith

> RV7 Flying

> Kolb Firestar II (in-progress)

> 

> 

> 

> 

> Read this topic online here:

> 

> http://forums.matronics.com/viewtopic.php?p=405880#405880

> 

> 

> 

> 

> 

> 

> 

> ===========

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

> ===========

> http://forums.matronics.com

> ===========

> le, List Admin.

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

> ===========

 -- 

 Zulu Delta

 Mk IIIC

 Thanks, Homer GBYM

 It isn't necessary to have relatives in Kansas City in order to be unhappy

Richard Pike

Joined: 09 Jan 2006
Posts: 1670
Location: Blountville, Tennessee

Posted: Sun Aug 04, 2013 5:36 am Post subject: Re: Need explanation of fuel system w/dual 5gal pickups

If switching tanks does not appeal to you, think about adding a hopper tank. Go to Home Depot and purchase some 4" PVC pipe and flat end caps. They sell 3 types of PVC pipe, one is thick wall and heavy, and the other is thin wall. The third type has a foam core,  don't get the foam core. Gasoline doesn't affect the PVC. Make it whatever size you can get to fit anywhere near the back seat and below the level of the stock tanks. Make up some appropriate brackets and clamp it securely in place. It doesn't need to be very big, it just needs to hold a quart or so and be the lowest point in the system.



NAPA auto parts sells a metal tire valve stem with a wide flat flange on each side and rubber gaskets, you can drill it out and use it as a fuel fitting, put it into the flat end cap of the pipe. 



Set it up so that both of your stock tanks drain into the hopper tank, and the hopper tank goes to your Facet pump. The fitting that goes to the Facet pump is obviously the lowest point in the system. Also rig it for a sump drain. Since this little hopper tank is below your stock tanks, you don't care if one of them drains dry, you only have to be on the ground before both of them drain dry.



If you want to spend about $150 for various pieces-parts (mostly on on brass T fittings) you can put in 2 of these things, mount them vertically beside the forwardmost stock tank, and gain a bit over 2 gallons of fuel.  Figuring out how to arrange all the plumbing will have you making up a real flow chart, but if you want 12 gallons of usable fuel, here's how to do it: http://www.bcchapel.org/pages/0003/FSIITankMods.html

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Sun Aug 04, 2013 6:52 am Post subject: Need explanation of fuel system w/dual 5gal pickups

Frank, Here you go.http://www.aircraftspruce.com/catalog/appages/whfsv.php



Rick



 



On Sun, Aug 4, 2013 at 7:44 AM, Frank <frank.goodnight(at)att.net (frank.goodnight(at)att.net)> wrote:

 	  Quote: 	
		   Richard

What is weather head valve?

Where can I get one?

How can I be sure it is good for

Fuel?

Thanks

Frank 



Sent from my iPhone

 

On Aug 4, 2013, at 7:07 AM, Richard Girard <aslsa.rng(at)gmail.com (aslsa.rng(at)gmail.com)> wrote:

 	  Quote: 	
		  Dave, I battled this one on my Mk III. My solution was to use a modified Weatherhead valve to get left, right, both, and off so I could control the tanks. The modification is simple. The Weatherhead valve has a nylon ball with two passages at right angles that meet in the center. There are four detents that control how the passages line up with the ports. Simply drill through one side so that there are now three passages in a "T" configuration. Which one of the original two you use to guide the drill is only dependent on where you want the handle to be when the the undrilled side of the ball is over the fuel inlet port (where you want the handle when the valve is in the OFF position.

  With this solution you have absolute control over how fuel is drawn from the tanks. On a cross country flight when I was running low on fuel and needed every available drop I was able to purposely run a tank dry and switch to the tank that still had fuel before the engine died. Having a Facet pump to boost fuel to the Mikuni pneumatic pump I got an instant prime when I switched tanks and the engine hardly stuttered before it had fuel from the other tank and resumed running.

  Yep, bad practice that I pulled off once and never repeated. The fact that I could do it at all was because the valve gave me complete control over the fuel supply.

Rick Girard

do not archive

  

On Sat, Aug 3, 2013 at 9:29 PM, dsmithlib <dsmithlib(at)ameritech.net (dsmithlib(at)ameritech.net)> wrote:

   	  Quote: 	
		  --> Kolb-List message posted by: "dsmithlib" <dsmithlib(at)ameritech.net (dsmithlib(at)ameritech.net)>

   

 I am rebuilding a Firestar II project.  It has two 5 gal tanks, I have the plans from the mid-90's and (I thought) I had a pretty good understanding of aviation fuel systems and venting.

 

 However, I am seeing both tanks fed together to a T and then up to the pump or primer etc..   What I am missing is how the fuel is drawn from the tanks equally.  It seems to me that once air is introduced to EITHER fuel pickup, the system will be fuel starved.

   

 I realize there is something I am not picking up from the drawings.  I do not see any depiction of the venting which may hold the key.  In any event, I would appreciate a few comments on best practices for plumbing the two standard 5 gal tanks.

   

 Thanks,

 Dave

 

 --------

 Dave Smith

 RV7 Flying

 Kolb Firestar II (in-progress)

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=405880#405880

 

 

 

 

 

 

 

 ===========

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

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

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

 ===========

 

 

 

 	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

    - Groucho Marx

 

   	  Quote: 	
		  



==========

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==========

cs.com

==========

matronics.com/contribution

==========



	






get="_blank">http://www.matronics.com/Navigator?Kolb-List

tp://forums.matronics.com

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



	


	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

_________________
The smallest miracle right in front of you is enough to make you happy....

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Sun Aug 04, 2013 6:59 am Post subject: Re: Need explanation of fuel system w/dual 5gal pickups

My Slingshot had two 5 gallon tanks with a connection tube between them close to the bottom so that they acted almost as if they were one tank. I say almost because the connection was not in the bottom but on the side wall close to the bottom. The line to the electric fuel pump was from the top in the rear of the two tanks since it is a bit lower than the front except in a dive. The vent from the top of front tank(which also connected to the top of the rear tank) went down and exited below the fuselage. Since the connection line was small (1/4") the flow between the two tanks was not nearly as fast as the rate you can fill the tanks. It is quicker to fill both than wait for one to drain to the other. 



If you don't mind putting holes in the bottom of the tank, which is what I would have done had I been the builder, the connection line will make them effectively one 10 gallon tank. RANS Aircraft has an excellent fuel tank fitting for the bottom of tanks and they do not leak.

_________________
Thom Riddle
Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
- Anonymous

frank goodnight

Joined: 27 Dec 2011
Posts: 126

Posted: Sun Aug 04, 2013 7:04 am Post subject: Need explanation of fuel system w/dual 5gal pickups

Richard

The metal tire valve you mentioned

Also makes an excelant fitting if you want to feed from the bottom of

The tanks. Just drill out the center 

And use a fuel proof gasket.

Used them for years my firestar.

Frank----they come in 2 sizes, the

Long ones work best.



Sent from my iPhone



On Aug 4, 2013, at 8:36 AM, "Richard Pike" <richard(at)bcchapel.org> wrote:



 	  Quote: 	
		   

 

 If switching tanks does not appeal to you, think about adding a hopper tank. Go to Home Depot and purchase some 4" PVC pipe and flat end caps. They sell 3 types of PVC pipe, one is thick wall and heavy, and the other is thin wall. The third type has a foam core,  don't get the foam core. Gasoline doesn't affect the PVC. Make it whatever size you can get to fit anywhere near the back seat and below the level of the stock tanks. Make up some appropriate brackets and clamp it securely in place. It doesn't need to be very big, it just needs to hold a quart or so and be the lowest point in the system.

 

 NAPA auto parts sells a metal tire valve stem with a wide flat flange on each side and rubber gaskets, you can drill it out and use it as a fuel fitting, put it into the flat end cap of the pipe. 

 

 Set it up so that both of your stock tanks drain into the hopper tank, and the hopper tank goes to your Facet pump. The fitting that goes to the Facet pump is obviously the lowest point in the system. Also rig it for a sump drain. Since this little hopper tank is below your stock tanks, you don't care if one of them drains dry, you only have to be on the ground before both of them drain dry.

 

 If you want to spend about $150 for various pieces-parts (mostly on on brass T fittings) you can put in 2 of these things, mount them vertically beside the forwardmost stock tank, and gain a bit over 2 gallons of fuel.  Figuring out how to arrange all the plumbing will have you making up a real flow chart, but if you want 12 gallons of usable fuel, here's how to do it: http://www.bcchapel.org/pages/0003/FSIITankMods.html

 

 --------

 Richard Pike

 Kolb MKIII N420P (420ldPoops)

 richard (at) bcchapel(dot)org

 Kingsport, TN 3TN0

 Now faith is the substance of things hoped for, the evidence of things not seen. 

 Hebrews 11:1

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=405898#405898

frank goodnight

Joined: 27 Dec 2011
Posts: 126

Posted: Sun Aug 04, 2013 8:30 am Post subject: Need explanation of fuel system w/dual 5gal pickups

Richard

Thanks , Got one on my701but didn't

Know it. Was going to buy new valves

And replumb,so i could run from both tanks ,your method is a lot quicker

Eaiser and cheaper.Love this Kolb list.

Frank



Sent from my iPhone



On Aug 4, 2013, at 9:52 AM, Richard Girard <aslsa.rng(at)gmail.com> wrote:



[quote] Frank, Here you go.

 http://www.aircraftspruce.com/catalog/appages/whfsv.php

 

 Rick

 

 

 On Sun, Aug 4, 2013 at 7:44 AM, Frank <frank.goodnight(at)att.net> wrote:

> Richard

> What is weather head valve?

> Where can I get one?

> How can I be sure it is good for

> Fuel?

> Thanks

> Frank 

> 

> Sent from my iPhone

> 

> On Aug 4, 2013, at 7:07 AM, Richard Girard <aslsa.rng(at)gmail.com> wrote:

> 

>> Dave, I battled this one on my Mk III. My solution was to use a modified Weatherhead valve to get left, right, both, and off so I could control the tanks.

>> The modification is simple. The Weatherhead valve has a nylon ball with two passages at right angles that meet in the center. There are four detents that control how the passages line up with the ports. Simply drill through one side so that there are now three passages in a "T" configuration. Which one of the original two you use to guide the drill is only dependent on where you want the handle to be when the the undrilled side of the ball is over the fuel inlet port (where you want the handle when the valve is in the OFF position.

>> With this solution you have absolute control over how fuel is drawn from the tanks. On a cross country flight when I was running low on fuel and needed every available drop I was able to purposely run a tank dry and switch to the tank that still had fuel before the engine died. Having a Facet pump to boost fuel to the Mikuni pneumatic pump I got an instant prime when I switched tanks and the engine hardly stuttered before it had fuel from the other tank and resumed running.

>> Yep, bad practice that I pulled off once and never repeated. The fact that I could do it at all was because the valve gave me complete control over the fuel supply.

>> 

>> Rick Girard

>> do not archive

>> 

>> 

>> On Sat, Aug 3, 2013 at 9:29 PM, dsmithlib <dsmithlib(at)ameritech.net> wrote:

>>> 

>>> 

>>> I am rebuilding a Firestar II project.  It has two 5 gal tanks, I have the plans from the mid-90's and (I thought) I had a pretty good understanding of aviation fuel systems and venting.

>>> 

>>> However, I am seeing both tanks fed together to a T and then up to the pump or primer etc..   What I am missing is how the fuel is drawn from the tanks equally.  It seems to me that once air is introduced to EITHER fuel pickup, the system will be fuel starved.

>>> 

>>> I realize there is something I am not picking up from the drawings.  I do not see any depiction of the venting which may hold the key.  In any event, I would appreciate a few comments on best practices for plumbing the two standard 5 gal tanks.

>>> 

>>> Thanks,

>>> Dave

>>> 

>>> --------

>>> Dave Smith

>>> RV7 Flying

>>> Kolb Firestar II (in-progress)

>>> 

>>> 

>>> 

>>> 

>>> Read this topic online here:

>>> 

>>> http://forums.matronics.com/viewtopic.php?p=405880#405880

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>>> 

>>> ===========

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

>>> ===========

>>> http://forums.matronics.com

>>> ===========

>>> le, List Admin.

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

>>> ===========

>> 

>> 

>> 

>> -- 

>> Zulu Delta

>> Mk IIIC

>> Thanks, Homer GBYM

>> 

>> It isn't necessary to have relatives in Kansas City in order to be unhappy.

>>   - Groucho Marx

>> 

>> 

>> 

>> ==========

>> ://www.matronics.com/Navigator?Kolb-List

>> ==========

>> cs.com

>> ==========

>> matronics.com/contribution

>> ==========

>> 

> 

> 

> get="_blank">http://www.matronics.com/Navigator?Kolb-List

> tp://forums.matronics.com

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

> 

 

 

 

 -- 

 Zulu Delta

 Mk IIIC

 Thanks, Homer GBYM

 

 It isn't necessary to have relatives in Kansas City in order to be unhappy

Frankd

Joined: 28 Mar 2008
Posts: 64

Posted: Sun Aug 04, 2013 8:44 am Post subject: Re: Need explanation of fuel system w/dual 5gal pickups

Hi Dave,



I have the two tank system in my MkIII Xtra. 

The fuel pickup tubes go to the bottom of both tanks and I have connected them with a T at the top and then this single fuel line I run down to a fuel pump placed at the height of the bottom of the tanks. 



The trick is to initially suck fuel from BOTH tanks so there is no air in the lines. 



Both 5Gal tanks are side by side so if one is full  and one is half full the fuel will eventually flow from the full to the lower until they are equal. 

My vent lines just plumb into the top of the tank and I run them up about 6 inches and then down to the outside of the plane. In case I go inverted the fuel will stay outside the aircraft. 



This system acts like one tank,  no switching required.  Just fill both up equally  and its fine.  

I'm thinking of adding another 5 gal tank and may add a valve as a control into the 1st two if I do that. 



Hope this helps.



Oh, I also have two fuel filters,  one just after the T at the top of the tank and one on the fuel pump.  No problems so far,  50Hrs flying.



FrankD

byoungplumbing(at)gmail.c
Guest

Posted: Sun Aug 04, 2013 9:17 am Post subject: Need explanation of fuel system w/dual 5gal pickups

I have never tried this, but offer it to you for your  consideration,,    you would have to do some experimenting to see  if the system works, or how hard to eliminate all the air.  

  

 if you  come out of the top of both tanks,,,  then loop the lines  to below both tanks  and put the tee from both tanks and the inlet to the  engine in the bottom of the cage.  you would have to start a siphon from  each tank to purge the air from both lines and establish a siphon.    then each tank will drain via the siphon line to the tee.  if one tank goes  empty the siphon for that tank will quit, the other will continue to siphon till  it is empty,  if one tank is empty the other tank will keep the area of the  tee (going to the engine) flooded with fuel, this should keep the engine happy  till the second tank empties and the second siphon is lost.   at that  point you are out of gas and are going to let gravity be a major part of flying  the plane.    down side would be if you had a vacuum leak that  stopped the siphon on one tank...  your engine could quit with one tank  full.    to prevent this,, you could put a â€œleft right or bothâ€  valve at the bottom the cage in place of a simple T,  

  

 just thinking out loud.

  

 boyd young

  

 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

I am rebuilding a Firestar II project. It has two 5 gal  tanks, I have the plans from the mid-90's and (I thought) I had a pretty good  understanding of aviation fuel systems and venting.



However, I am seeing  both tanks fed together to a T and then up to the pump or primer etc.. What I am  missing is how the fuel is drawn from the tanks equally. It seems to me that  once air is introduced to EITHER fuel pickup, the system will be fuel  starved.



I realize there is something I am not picking up from the  drawings. I do not see any depiction of the venting which may hold the key. In  any event, I would appreciate a few comments on best practices for plumbing the  two standard 5 gal tanks.



Thanks,

Dave



 

[quote][b]

dan42101(at)yahoo.com
Guest

Posted: Sun Aug 04, 2013 10:07 am Post subject: Need explanation of fuel system w/dual 5gal pickups

One way to do it is to just use the front tank to feed the carbs via the Mikuni pump, and use a facet pump to transfer fuel in flight.  When you feel fuel on the back of your neck you know your font tank is full...  Once you feel the fuel on your neck you will never take your hand off the pump switch during a transfer again.

Some good fuel system  suggestions: 

http://www.challengers101.com/FuelSys.html



 

        From: dsmithlib <dsmithlib(at)ameritech.net>

 To: kolb-list(at)matronics.com 

 Sent: Saturday, August 3, 2013 9:29 PM

 Subject: Need explanation of fuel system w/dual 5gal pickups

  

 

--> Kolb-List message posted by: "dsmithlib" <dsmithlib(at)ameritech.net (dsmithlib(at)ameritech.net)>



I am rebuilding a Firestar II project.  It has two 5 gal tanks, I have the plans from the mid-90's and (I thought) I had a pretty good understanding of aviation fuel systems and venting.



However, I am seeing both tanks fed together to a T and then up to the pump or primer etc..   What I am missing is how the fuel is drawn  from the tanks equally.  It seems to me that once air is introduced to EITHER fuel pickup, the system will be fuel starved.  



I realize there is something I am not picking up from the drawings.  I do not see any depiction of the venting which may hold the key.  In any event, I would appreciate a few comments on best practices for plumbing the two standard 5 gal tanks.



Thanks,

Dave



--------

Dave Smith

RV7 Flying

Kolb Firestar II (in-progress)





Read this topic online here:



http://forums.matronics.com/vi-> http://ww=======================

 

 

  

 [quote][b]

dsmithlib

Joined: 06 Jul 2013
Posts: 2
Location: Libertyville, IL

Posted: Mon Aug 05, 2013 8:10 am Post subject: Re: Need explanation of fuel system w/dual 5gal pickups

Thank you to all for replying.

From what I have learned here......



I will...

use individual pickups from the top

then connect with a T

then go to a filter

then to a elec facet pump

then to the pulse pump



I will T off at some point for primer



They will be well vented but I am not sure how I will plumb the vents at this moment......sounds like they will also get T'd and then plumbed overboard.



Thank you  !

Thank you  !

Thank you  !

_________________
Dave Smith
RV7 Flying
Kolb Firestar II (in-progress)

neilsenrm(at)gmail.com
Guest

Posted: Mon Aug 05, 2013 11:17 am Post subject: Need explanation of fuel system w/dual 5gal pickups

I keep hearing people say they don't want to put the fuel pickup on the bottom of their tanks. I don't understand their issues. I have been flying my VW powered MKIIIC for fifteen years. I use the press fit bushings in the standard Kolb plastic tanks and have never had a seeping fuel issue. About 7-8 years ago I replaced the tanks just to be safe and again no issues. I now have the 6 gallon tanks ready to install and yes I have drilled the bottoms and installed the press fit bushings. I insert a fitting that has a finger strainer and shut off valve.  



My theory is feeding fuel from the bottom is the most reliable way to get fuel to my engine because there are fewer things that can go wrong. Fuel feeds evenly from both tanks and if one tank gets filled more than the other they will equalize in time. Again I have never had a press fit bushing leak but I have had a fuel line leak. When the fuel line developed a leak it was dangerous but it didn't cause a engine failure like would have happened if I was feeding from the top of the tanks. I did notice a fuel smell that got me looking. It would seem that fuel seepage would be the worst case problem for bottom feed. If you top feed and you get even a minor air leak you wouldn't know till engine start or worst case in the air.

 



I use a stepped drill bit to drill the hole in the plastic fuel tanks for the fuel bushings. I think they drill a more rounded hole in thin plastic. Then I very carefully debur the holes.



 

I tee the fuel tanks together. I have flown many different GA airplanes that have fuel selectors and they are a pain. Something else that you HAVE to do. On low wing airplanes with wing tanks, where it is necessary it is a necessary evil, it is ok. Why add something like a fuel selector that adds to the work load and is a potential problem?

 



Just my opinion. As always this is worth what you paid for it.

Rick Neilsen

1st Redrive VW powered MKIIIC

On Sun, Aug 4, 2013 at 12:44 PM, Frankd <FDucker(at)aol.com (FDucker(at)aol.com)> wrote: [quote] --> Kolb-List message posted by: "Frankd" <FDucker(at)aol.com (FDucker(at)aol.com)>

 

 Hi Dave,

 

 I have the two tank system in my MkIII Xtra.

 The fuel pickup tubes go to the bottom of both tanks and I have connected them with a T at the top and then this single fuel line I run down to a fuel pump placed at the height of the bottom of the tanks.

 

 The trick is to initially suck fuel from BOTH tanks so there is no air in the lines.

 

 Both 5Gal tanks are side by side so if one is full  and one is half full the fuel will eventually flow from the full to the lower until they are equal.

 My vent lines just plumb into the top of the tank and I run them up about 6 inches and then down to the outside of the plane. In case I go inverted the fuel will stay outside the aircraft.

 

 This system acts like one tank,  no switching required.  Just fill both up equally  and its fine.

 I'm thinking of adding another 5 gal tank and may add a valve as a control into the 1st two if I do that.

 

 Hope this helps.

 

 Oh, I also have two fuel filters,  one just after the T at the top of the tank and one on the fuel pump.  No problems so far,  50Hrs flying.

 

 FrankD

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=405914#405914

 

 

 

 

 

 

 

 ===========

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

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

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

 ===========

 

 

 

 [b]

jim.baker(at)windstream.n
Guest

Posted: Mon Aug 05, 2013 2:45 pm Post subject: Need explanation of fuel system w/dual 5gal pickups

Murphy said it best -  "Anything that can go wrong, will go wrong".

  

 Yours doesn't leak and hasn't leaked. That's not to say that at some time in the  future it won't leak. The top plumbed units won't leak as yours might but still  have a slight chance of leaking thru a cracked seam or some other mechanism. 

  

 There is no advantage to top plumbed except possibly access and maintenance.  Top plumbed allows me to but a bronze filtered clunk at the bottom of the tank  standpipe without having to pull the tank out. All maintenance can be done with  the tank as is, where is. Either methodology, top or bottom, will work, just  depends on your point of view. I've had the same tanks for 18 years. There was  never a time when I doubted the integrity of fuel delivery methodology chosen.  Personal choice, not a denouncement.

  

  

  

  

 Date sent:                  Mon, 5 Aug 2013 15:17:02 -0400

 Subject:                     Re: Re: Need explanation of fuel system w/dual 5gal pickups

 From:                         Rick Neilsen <neilsenrm(at)gmail.com>

 To:                            kolb-list(at)matronics.com

 Send reply to:            kolb-list(at)matronics.com

  

 > 

 > I keep hearing people say they don't want to put the fuel pickup on the bottom of their tanks. I 

 > don't understand their issues. I have been flying my VW powered MKIIIC for fifteen years. I use 

 > the press fit bushings in the standard Kolb plastic tanks and have never had a seeping fuel 

 > issue. About 7-8 years ago I replaced the tanks just to be safe and again no issues. I now have 

 > the 6 gallon tanks ready to install and yes I have drilled the bottoms and installed the press fit 

 > bushings. I insert a fitting that has a finger strainer and shut off valve.

 > 

 > My theory is feeding fuel from the bottom is the most reliable way to get fuel to my engine 

 > because there are fewer things that can go wrong. Fuel feeds evenly from both tanks and if one 

 > tank gets filled more than the other they will equalize in time. Again I have never had a press fit 

 > bushing leak but I have had a fuel line leak. When the fuel line developed a leak it was 

 > dangerous but it didn't cause a engine failure like would have happened if I was feeding from the 

 > top of the tanks. I did notice a fuel smell that got me looking. It would seem that fuel seepage 

 > would be the worst case problem for bottom feed. If you top feed and you get even a minor air 

 > leak you wouldn't know till engine start or worst case in the air.

 > 

 > I use a stepped drill bit to drill the hole in the plastic fuel tanks for the fuel bushings. I think they 

 > drill a more rounded hole in thin plastic. Then I very carefully debur the holes.

 > 

 > I tee the fuel tanks together. I have flown many different GA airplanes that have fuel selectors 

 > and they are a pain. Something else that you HAVE to do. On low wing airplanes with wing 

 > tanks, where it is necessary it is a necessary evil, it is ok. Why add something like a fuel selector 

 > that adds to the work load and is a potential problem?

 > 

 > Just my opinion. As always this is worth what you paid for it.

 > 

 > Rick Neilsen

 > 1st Redrive VW powered MKIIIC

 > 

 > On Sun, Aug 4, 2013 at 12:44 PM, Frankd <FDucker(at)aol.com> wrote:

 >     --> Kolb-List message posted by: "Frankd" <FDucker(at)aol.com>

 >     

 >     Hi Dave,

 >     

 >     I have the two tank system in my MkIII Xtra.

 >     The fuel pickup tubes go to the bottom of both tanks and I have connected  them with a T at 

 >     the top and then this single fuel line I run down to a fuel pump placed at the  height of the 

 >     bottom of the tanks.

 >     

 >     The trick is to initially suck fuel from BOTH tanks so there is no air in the  lines.

 >     

 >     Both 5Gal tanks are side by side so if one is full and one is half full the fuel  will eventually 

 >     flow from the full to the lower until they are equal.

 >     My vent lines just plumb into the top of the tank and I run them up about 6  inches and then 

 >     down to the outside of the plane. In case I go inverted the fuel will stay  outside the aircraft.

 >     

 >     This system acts like one tank, no switching required. Just fill both up  equally and its 

 >     fine.

 >     I'm thinking of adding another 5 gal tank and may add a valve as a control  into the 1st two 

 >     if I do that.

 >     

 >     Hope this helps.

 >     

 >     Oh, I also have two fuel filters, one just after the T at the top of the tank and  one on the 

 >     fuel pump. No problems so far, 50Hrs flying.

 >     

 >     FrankD

 >     

 >     

 >     

 >     

 >     Read this topic online here:

 >     

 >     http://forums.matronics.com/viewtopic.php?p=405914#405914

 >     

 >     

 >     

 >     

 >     

 >     

 >     

 >     ===========

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

 >     ===========

 >     http://forums.matronics.com

 >     ===========

 >     le, List Admin.

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

 >     ===========

 >     

 >     

 > 

 > 

 > 

 > http://www.matronics.com/Navigator?Kolb-List

 > 

 > 

  

  

 Jim Baker

 Elmore City, OK

 580.788.2779 home

 405.426.5377 cell

   

    [quote][b]

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Mon Aug 05, 2013 6:35 pm Post subject: Need explanation of fuel system w/dual 5gal pickups

When I decided to redo the fuel system in my Mk III I debated top or bottom draw. Then I pulled the old tanks out and the grommet was split almost to the fitting. Pushed me in favor of top draw, plus that was the factory recommendation. Since Mr. Murphy never sleeps, I had an engine out landing because I didn't have any sort of filter on the top pickups. Fixed that and never had another fuel problem. Venting. Something I haven't seen discussed on the forum is venting that will not become a drain if you inadvertently do a low altitude outside loop (flip over on landing). The LongEZ crowd recommends a vent design that includes a suction break to prevent such an occurrence. I never got it implemented, but I will during this rebuild. Just a thought.

 



Rick Girard

do not archive



On Mon, Aug 5, 2013 at 5:45 PM, Jim Baker <jim.baker(at)windstream.net (jim.baker(at)windstream.net)> wrote:

  	  Quote: 	
		         Murphy said it best -  "Anything that can go wrong, will go wrong".

 

 

 Yours doesn't leak and hasn't leaked. That's not to say that at some time in the  future it won't leak. The top plumbed units won't leak as yours might but still  have a slight chance of leaking thru a cracked seam or some other mechanism. 

 

 

 There is no advantage to top plumbed except possibly access and maintenance.  Top plumbed allows me to but a bronze filtered clunk at the bottom of the tank  standpipe without having to pull the tank out. All maintenance can be done with  the tank as is, where is. Either methodology, top or bottom, will work, just  depends on your point of view. I've had the same tanks for 18 years. There was  never a time when I doubted the integrity of fuel delivery methodology chosen.  Personal choice, not a denouncement.

 

 

 

 

 

 

 

 

 Date sent:                  Mon, 5 Aug 2013 15:17:02 -0400

 Subject:                     Re: Kolb-List: Re: Need explanation of fuel system w/dual 5gal pickups

 From:                         Rick Neilsen <neilsenrm(at)gmail.com (neilsenrm(at)gmail.com)>

 To:                            kolb-list(at)matronics.com (kolb-list(at)matronics.com)

 Send reply to:            kolb-list(at)matronics.com (kolb-list(at)matronics.com)

 

 

 > 

 > I keep hearing people say they don't want to put the fuel pickup on the bottom of their tanks. I 

 > don't understand their issues. I have been flying my VW powered MKIIIC for fifteen years. I use 

 > the press fit bushings in the standard Kolb plastic tanks and have never had a seeping fuel 

 > issue. About 7-8 years ago I replaced the tanks just to be safe and again no issues. I now have 

 > the 6 gallon tanks ready to install and yes I have drilled the bottoms and installed the press fit 

 > bushings. I insert a fitting that has a finger strainer and shut off valve.

 > 

 > My theory is feeding fuel from the bottom is the most reliable way to get fuel to my engine 

 > because there are fewer things that can go wrong. Fuel feeds evenly from both tanks and if one 

 > tank gets filled more than the other they will equalize in time. Again I have never had a press fit 

 > bushing leak but I have had a fuel line leak. When the fuel line developed a leak it was 

 > dangerous but it didn't cause a engine failure like would have happened if I was feeding from the 

 > top of the tanks. I did notice a fuel smell that got me looking. It would seem that fuel seepage 

 > would be the worst case problem for bottom feed. If you top feed and you get even a minor air 

 > leak you wouldn't know till engine start or worst case in the air.

 > 

 > I use a stepped drill bit to drill the hole in the plastic fuel tanks for the fuel bushings. I think they 

 > drill a more rounded hole in thin plastic. Then I very carefully debur the holes.

 > 

 > I tee the fuel tanks together. I have flown many different GA airplanes that have fuel selectors 

 > and they are a pain. Something else that you HAVE to do. On low wing airplanes with wing 

 > tanks, where it is necessary it is a necessary evil, it is ok. Why add something like a fuel selector 

 > that adds to the work load and is a potential problem?

 > 

 > Just my opinion. As always this is worth what you paid for it.

 > 

 > Rick Neilsen

 > 1st Redrive VW powered MKIIIC

 > 

 > On Sun, Aug 4, 2013 at 12:44 PM, Frankd <FDucker(at)aol.com (FDucker(at)aol.com)> wrote:

  >     --> Kolb-List message posted by: "Frankd" <FDucker(at)aol.com (FDucker(at)aol.com)>

  >     

 >     Hi Dave,

 >     

 >     I have the two tank system in my MkIII Xtra.

 >     The fuel pickup tubes go to the bottom of both tanks and I have connected  them with a T at 

 >     the top and then this single fuel line I run down to a fuel pump placed at the  height of the 

 >     bottom of the tanks.

 >     

 >     The trick is to initially suck fuel from BOTH tanks so there is no air in the  lines.

 >     

 >     Both 5Gal tanks are side by side so if one is full and one is half full the fuel  will eventually 

 >     flow from the full to the lower until they are equal.

 >     My vent lines just plumb into the top of the tank and I run them up about 6  inches and then 

 >     down to the outside of the plane. In case I go inverted the fuel will stay  outside the aircraft.

 >     

 >     This system acts like one tank, no switching required. Just fill both up  equally and its 

 >     fine.

 >     I'm thinking of adding another 5 gal tank and may add a valve as a control  into the 1st two 

 >     if I do that.

 >     

 >     Hope this helps.

 >     

 >     Oh, I also have two fuel filters, one just after the T at the top of the tank and  one on the 

 >     fuel pump. No problems so far, 50Hrs flying.

 >     

 >     FrankD

 >     

 >     

 >     

 >     

 >     Read this topic online here:

 >     

 >     http://forums.matronics.com/viewtopic.php?p=405914#405914

  >     

 >     

 >     

 >     

 >     

 >     

 >     

 >     ===========

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

  >     ===========

 >     http://forums.matronics.com

 >     ===========

 >     le, List Admin.

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

  >     ===========

 >     

 >     

 > 

 > 

 > 

 



 	  Quote: 	
		   http://www.matronics.com/Navigator?Kolb-List

  > 
	


 > 

 

 

 

 

 Jim Baker

 Elmore City, OK

 [url=tel:580.788.2779]580.788.2779[/url] home

 [url=tel:405.426.5377]405.426.5377[/url] cell

   

     	  Quote: 	
		  



get="_blank">http://www.matronics.com/Navigator?Kolb-List

tp://forums.matronics.com

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



	




	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

_________________
The smallest miracle right in front of you is enough to make you happy....

jim.baker(at)windstream.n
Guest

Posted: Mon Aug 05, 2013 7:26 pm Post subject: Need explanation of fuel system w/dual 5gal pickups

I generally recommend a sintered bronze filter as a clunk on the bottom of the  standpipe. For those unfamiliar with the term clunk, comes from the radio control  world where the fuel pickup was guided by G forces to follow the fuel's location  in the tank. It's close enough to the bottom of the tank that should the filter-hose-standpipe connection be compromised you'll still draw fuel from the standpipe, it  just won't be filtered and you won't get that last little bit out of the tank. If you're  flying that close to the edge....well......

  

  

 Date sent:                  Mon, 5 Aug 2013 21:35:18 -0500

 Subject:                     Re: Re: Need explanation of fuel system w/dual 5gal pickups

 From:                         Richard Girard <aslsa.rng(at)gmail.com>

 To:                            "kolb-list(at)matronics.com" <kolb-list(at)matronics.com>

 Send reply to:            kolb-list(at)matronics.com

  

 > 

 > When I decided to redo the fuel system in my Mk III I debated top or bottom draw. Then I pulled 

 > the old tanks out and the grommet was split almost to the fitting. Pushed me in favor of top draw, 

 > plus that was the factory recommendation. Since Mr. Murphy never sleeps, I had an engine out 

 > landing because I didn't have any sort of filter on the top pickups. Fixed that and never had 

 > another fuel problem.

 > Venting. Something I haven't seen discussed on the forum is venting that will not become a drain 

 > if you inadvertently do a low altitude outside loop (flip over on landing). The LongEZ crowd 

 > recommends a vent design that includes a suction break to prevent such an occurrence. I never 

 > got it implemented, but I will during this rebuild. Just a thought.

 > 

 > Rick Girard

 > do not archive

 > 

 > 

 > 

 > On Mon, Aug 5, 2013 at 5:45 PM, Jim Baker <jim.baker(at)windstream.net > wrote:

 >     Murphy said it best - "Anything that can go wrong, will go wrong".

 > 

 >     Yours doesn't leak and hasn't leaked. That's not to say that at some time in the future it 

 >     won't leak. The top plumbed units won't leak as yours might but still have a slight chance of 

 >     leaking thru a cracked seam or some other mechanism. 

 > 

 >     There is no advantage to top plumbed except possibly access and maintenance. Top 

 >     plumbed allows me to but a bronze filtered clunk at the bottom of the tank standpipe 

 >     without having to pull the tank out. All maintenance can be done with the tank as is, where 

 >     is. Either methodology, top or bottom, will work, just depends on your point of view. I've had 

 >     the same tanks for 18 years. There was never a time when I doubted the integrity of fuel 

 >     delivery methodology chosen. Personal choice, not a denouncement.

 > 

 > 

 > 

 > 

 >     Date sent:Mon, 5 Aug 2013 15:17:02 -0400

 >     Subject:Re: Re: Need explanation of fuel system w/dual 5gal 

 >     pickups

 >     From:Rick Neilsen <neilsenrm(at)gmail.com>

 >     To:kolb-list(at)matronics.com

 >     Send reply to:kolb-list(at)matronics.com

 > 

 >     > 

 >     > I keep hearing people say they don't want to put the fuel pickup on the  bottom of their 

 >     tanks. I 

 >     > don't understand their issues. I have been flying my VW powered MKIIIC  for fifteen 

 >     years. I use 

 >     > the press fit bushings in the standard Kolb plastic tanks and have never  had a seeping 

 >     fuel 

 >     > issue. About 7-8 years ago I replaced the tanks just to be safe and again  no issues. I 

 >     now have 

 >     > the 6 gallon tanks ready to install and yes I have drilled the bottoms and  installed the 

 >     press fit 

 >     > bushings. I insert a fitting that has a finger strainer and shut off valve.

 >     > 

 >     > My theory is feeding fuel from the bottom is the most reliable way to get  fuel to my engine 

 >     > because there are fewer things that can go wrong. Fuel feeds evenly from  both tanks and 

 >     if one 

 >     > tank gets filled more than the other they will equalize in time. Again I have  never had a 

 >     press fit 

 >     > bushing leak but I have had a fuel line leak. When the fuel line developed  a leak it was 

 >     > dangerous but it didn't cause a engine failure like would have happened if  I was feeding 

 >     from the 

 >     > top of the tanks. I did notice a fuel smell that got me looking. It would  seem that fuel 

 >     seepage 

 >     > would be the worst case problem for bottom feed. If you top feed and you  get even a 

 >     minor air 

 >     > leak you wouldn't know till engine start or worst case in the air.

 >     > 

 >     > I use a stepped drill bit to drill the hole in the plastic fuel tanks for the fuel  bushings. I 

 >     think they 

 >     > drill a more rounded hole in thin plastic. Then I very carefully debur the  holes.

 >     > 

 >     > I tee the fuel tanks together. I have flown many different GA airplanes that  have fuel 

 >     selectors 

 >     > and they are a pain. Something else that you HAVE to do. On low wing  airplanes with 

 >     wing 

 >     > tanks, where it is necessary it is a necessary evil, it is ok. Why add  something like a fuel 

 >     selector 

 >     > that adds to the work load and is a potential problem?

 >     > 

 >     > Just my opinion. As always this is worth what you paid for it.

 >     > 

 >     > Rick Neilsen

 >     > 1st Redrive VW powered MKIIIC

 >     > 

 >     > On Sun, Aug 4, 2013 at 12:44 PM, Frankd <FDucker(at)aol.com> wrote:

 >     > --> Kolb-List message posted by: "Frankd" <FDucker(at)aol.com>

 >     > 

 >     > Hi Dave,

 >     > 

 >     > I have the two tank system in my MkIII Xtra.

 >     > The fuel pickup tubes go to the bottom of both tanks and I have connected  them with a 

 >     T at 

 >     > the top and then this single fuel line I run down to a fuel pump placed at  the height of 

 >     the 

 >     > bottom of the tanks.

 >     > 

 >     > The trick is to initially suck fuel from BOTH tanks so there is no air in the  lines.

 >     > 

 >     > Both 5Gal tanks are side by side so if one is full and one is half full the  fuel will 

 >     eventually 

 >     > flow from the full to the lower until they are equal.

 >     > My vent lines just plumb into the top of the tank and I run them up about 6  inches and 

 >     then 

 >     > down to the outside of the plane. In case I go inverted the fuel will stay  outside the 

 >     aircraft.

 >     > 

 >     > This system acts like one tank, no switching required. Just fill both up  equally and its 

 >     > fine.

 >     > I'm thinking of adding another 5 gal tank and may add a valve as a control  into the 1st 

 >     two 

 >     > if I do that.

 >     > 

 >     > Hope this helps.

 >     > 

 >     > Oh, I also have two fuel filters, one just after the T at the top of the tank  and one on 

 >     the 

 >     > fuel pump. No problems so far, 50Hrs flying.

 >     > 

 >     > FrankD

 >     > 

 >     > 

 >     > 

 >     > 

 >     > Read this topic online here:

 >     > 

 >     > http://forums.matronics.com/viewtopic.php?p=405914#405914

 >     > 

 >     > 

 >     > 

 >     > 

 >     > 

 >     > 

 >     > 

 >     > ===========

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

 >     > ===========

 >     > http://forums.matronics.com

 >     > ===========

 >     > le, List Admin.

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

 >     > ===========

 >     > 

 >     > 

 >     > 

 >     > 

 >     > 

 > 

 > 

 >     > http://www.matronics.com/Navigator?Kolb-List

 >     > 

 >     > 

 > 

 > 

 >     Jim Baker

 >     Elmore City, OK

 >     580.788.2779 home

 >     405.426.5377 cell

 >     

 >     

 >     

 >     get="_blank">http://www.matronics.com/Navigator?Kolb-List

 >     tp://forums.matronics.com

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

 >     

 > 

 > 

 > 

 > 

 > 

 > 

 > -- 

 > Zulu Delta

 > Mk IIIC

 > Thanks, Homer GBYM

 > 

 > It isn't necessary to have relatives in Kansas City in order to be unhappy.

 >  - Groucho Marx

 > 

 > 

 > http://www.matronics.com/Navigator?Kolb-List

 > 

 > 

  

  

 Jim Baker

 Elmore City, OK

 580.788.2779 home

 405.426.5377 cell

   

    [quote][b]

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Tue Aug 06, 2013 12:51 am Post subject: Need explanation of fuel system w/dual 5gal pickups

 	  Quote: 	
		   I use the press fit bushings in the standard Kolb plastic tanks


	


I am not 100% sure I know what you mean here. Is 'press fit' the gadget that

is held in place in the hole by a neoprene grommet? It is a short tube with

a sort of barb on the end so the fuel line won't come off?



 	  Quote: 	
		   Venting. Something I haven't seen discussed on the forum is venting that

will not become a drain
	




The circle track racers wind the vent tube around the tank 2-3 times.

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

neilsenrm(at)gmail.com
Guest

Posted: Tue Aug 06, 2013 5:11 am Post subject: Need explanation of fuel system w/dual 5gal pickups

George

The press fit bushings are ultralight/light plane standard fuel fittings They are inserted into a hole in plastic fuel tanks. They are a fuel proof rubber like material. After they are inserted a metal fuel fitting is pressed into the bushing which locks the bushing in place and makes the assembly highly leak resistant. They do require that the proper sized hole is drilled, that is the hole is carefully debured, and the fuel fitting is lightly lubricated when it is installed.  

Rick Neilsen

Redrive VW Powered MKIIIC   

On Tue, Aug 6, 2013 at 4:51 AM, George Bearden <gab16(at)sbcglobal.net (gab16(at)sbcglobal.net)> wrote:

 [quote]--> Kolb-List message posted by: "George Bearden" <gab16(at)sbcglobal.net (gab16(at)sbcglobal.net)>

 > I use the press fit bushings in the standard Kolb plastic tanks

 I am not 100% sure I know what you mean here. Is 'press fit' the gadget that

 is held in place in the hole by a neoprene grommet? It is a short tube with

 a sort of barb on the end so the fuel line won't come off?

 > Venting. Something I haven't seen discussed on the forum is venting that

 will not become a drain

 The circle track racers wind the vent tube around the tank 2-3 times.

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