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craig(at)craigandjean.com
Guest

Posted: Sun May 10, 2009 11:32 am Post subject: 701 fuel system design

I've seen a number of different fuel system designs on 701s. My big worries

are the placement of the fuel valve(s) and the gascolator. I want the

capability to select left, right or both to be able to control uneven flow.

Normally I would fly with "both" but switch to left or right if one tank was

draining faster. I'd also prefer the gascolator(s) to be where the Zenith

plans call for them (behind seats) as I'd like a gascolator to be at the

actual low point in the system. I know that some builders place their

gascolators on the firewall as a localized low point. But with the

gascolator forward I just don't see how you will ever get water or junk out

of the other low points in the system.



I'd like a "real" gascolator but placed where the plans call for the Zenith

"box". But it is tricky to mount a conventional gascolator there such that

you can drain it and open it for cleaning,



Places I have seen valves with pros and cons:



- Zenith design with off/on valve on floor by flap handle. Pros: single

gascolator behind seats, don't need access to valve during flight. Cons: no

"both" position.



- behind copilot's head towards the top off the outside wall. Pros: short

runs on lines from individual tanks, single "down" line to a single

gascolator. Cons: awkward to reach.



- centered on crossbar behind and above pilot and copilot just below roof.

Pros and cons are like above.



- on floor near flap handle. Pros better (but not great) access. I've got

chunky thighs and reaching (let alone seeing) the valve is hard. Not an

issue with an off/on valve but more important with a left-both-right valve.

Cons: two gascolators behind seats.



- on panel. Pros: good access to, and visibility of valve handle. Cons:

probably need actual valve on firewall with extension to panel.

One interesting idea I saw (N701RR?) is to not run the line(s) down, behind

the seats and then forward. Instead run them forward from the wing roots and

then down the diagonal steel tubes to the glare shield and firewall.



How have others thought this through?



-- Craig

lgold(at)quantum-associat
Guest

Posted: Sun May 10, 2009 3:51 pm Post subject: 701 fuel system design

Craig,

My kit came with 4 tanks (40 Gal) and I did not like the idea of routing the

fuel lines and gascolator behind the seat where I would not be able to

detect leaks.

I am pleased with my installation. I ran the lines from the tanks to the

forward wing root on each side where I put selector valve with inside tank,

outside tank, and off positions. From their I ran the stainless mesh covered

fuel lines down and forward to the fire wall along the steel frame at the

sides of the windshield. I placed the gascolator forward of the firewall on

the bottom-most part of the firewall away from the exhaust system. I was

concerned about potential vapor lock, but a week of flying in 100+ degree

weather in Death Valley and Nevada & Arizona high desert dispelled this

concern. 

If I has only a single tank in each wing I would use the same setup with an

on-off selector switch on each wing root. Simple and safe.

Les 



--

craig(at)craigandjean.com
Guest

Posted: Mon May 11, 2009 10:56 am Post subject: 701 fuel system design

Thanks Les,



Running the lines forward looks appealing. Do you have any pictures? How do

you protect the lines where they pass through the glare shield - just the SS

braid?



BTW: if you ever come out to fly the canyons in southern Utah feel free to

drop by and visit me in Northern Utah at 36U in Heber, UT.



-- Craig



--

lrm(at)skyhawg.com
Guest

Posted: Mon May 11, 2009 6:20 pm Post subject: 701 fuel system design

Check out my page on fuelsystem, you might find it interesting. 

www.skyhawg.com/fuelsystem.html.  Take care, Larry, N1345L



Craig Payne wrote:

[quote] 

 

 Thanks Les,

 

 Running the lines forward looks appealing. Do you have any pictures? How do

 you protect the lines where they pass through the glare shield - just the SS

 braid?

 

 BTW: if you ever come out to fly the canyons in southern Utah feel free to

 drop by and visit me in Northern Utah at 36U in Heber, UT.

 

 -- Craig

 

 --

craig(at)craigandjean.com
Guest

Posted: Mon May 11, 2009 8:40 pm Post subject: 701 fuel system design

Thanks, food for thought.



-- Craig



--

jetboy

Joined: 22 Jul 2006
Posts: 233

Posted: Tue May 12, 2009 12:16 am Post subject: Re: 701 fuel system design

There are a few guidelines I was told by an experimental builder, that all fuel lines should run downhill to the lowest point, of a drainable location, thence travel uphill to the carb inlet.



With the CZAW layout supplied, most of this was not possible due to the location of the andair fuel selector on one side of the rear cabin meaning the fuel line from the other side had to travel up and over to the valve.



I scrapped that layout, instead running the fuel lines down from the cabin wing roots, behind the pillars, across the rear of the seat back, into the fuel selector which is located just above the control tunnel mounted on the seat back panel. There is an area there, inside the working arc of the control system, that clears everything. The single fuel line exits the valve, runs down and across to an ACS gascolator on the right side panel just aft of the main gear mountings. Drain valve hangs through a hole there.  mounting was easy with a P clamp around each line connection. The otlet line runs along the floor on the right side, thru the firewall and up to the carb. As I have a Jabiru, with a low carb position and gravity feed I have not required any fuel pumps.



I found the location of the fuel selector, forward facing and between the seats, easy to reach and operate - perhaps harder to see but easy to feel the correct position, and I orientated it so the pointer is towards the tank selected (had to re-label the faceplate)



Hope this explanation helps the planes too far away for a photo right now.



Ralph

_________________
Ralph - CH701 / 2200a

lgold(at)quantum-associat
Guest

Posted: Fri May 15, 2009 2:46 pm Post subject: 701 fuel system design

Craig,

I'll take some pictures this weekend and send them out. I'm not certain what

a glare shield is, but each time I went through anything with the SS fuel

lines I used a rubber grommet.

FYI, I flew my 701 from San Francisco to S. Utah and Arizona last summer.

This summer I fly to Oshkosh, but would like to fly to N. Utah one of these

days...

Les   



--

craig(at)craigandjean.com
Guest

Posted: Fri May 15, 2009 3:04 pm Post subject: 701 fuel system design

Thanks. The glare shield is the curved sheet on top and between the firewall

and instrument panel, aka top front skin. 7F14-4



If you pass through northern Utah on your way to or from Oshkosh and want to

stop at 36U let me know.



-- Craig



--

d.shrader

Joined: 21 Nov 2008
Posts: 38

Posted: Tue Jun 30, 2009 8:51 pm Post subject: Re: 701 fuel system design

Les



   I am installing Aux. tanks also and that is my idea also "selectors at wing root Main/Aux/off" then to the normal gascolator and to a firewall shutoff. My question for you is what selectors did u use and can u share pics of your instlation?



Also is there any problem with the selectors at the wing root and removing the wing?



Thanks Dave

Curt.Thompson(at)verizon.
Guest

Posted: Tue Jun 30, 2009 9:08 pm Post subject: 701 fuel system design

There is one CH701 incident in the NTSB database where the pilot forgot to

turn the valve off on one of the lines when he landed.  He normally did

that.  When he got in next time, he turned the valve off instead of on.

Engine ran out of fuel shortly after takeoff.



BTW, I found a dozen or so incident reports in the database.  Only one

fatal.  Most were engine/fuel related.



Curt



--

xl(at)prosody.org
Guest

Posted: Tue Jun 30, 2009 9:53 pm Post subject: 701 fuel system design

I have a program that goes through the NTSB database daily looking

for Zenith incidents. Last count, 25 701, 6 801, and a few other 701s

under the Zenair model. The report is at:

NTSB Accident Data for Zenith, Zodiac, Zenair, 801, 701, 601, amd,

  czech as of 06/30/2009 04:04 GMT-07:00

http://www.cleanh2o.com/633z/ntsb/



Joe E (at) BFI

N633Z, 585 hours + climbing

CH601XL



p.s. I'll be working the ramp at the AWO flyin next week,

      when I can fly in from BFI. My plane will be there if I am.

On Tue, 30 Jun 2009, Curt Thompson wrote:

 	  Quote: 	
		   

 .......snip

 BTW, I found a dozen or so incident reports in the database.  Only one

 fatal.  Most were engine/fuel related.

d.shrader

Joined: 21 Nov 2008
Posts: 38

Posted: Tue Jun 30, 2009 11:56 pm Post subject: Re: 701 fuel system design

 	  Curt.Thompson(at)verizon. wrote: 	
		  There is one CH701 incident in the NTSB database where the pilot forgot to

turn the valve off on one of the lines when he landed.  He normally did

that.  When he got in next time, he turned the valve off instead of on.

Engine ran out of fuel shortly after takeoff.



BTW, I found a dozen or so incident reports in the database.  Only one

fatal.  Most were engine/fuel related.



Curt



-- 	




Too true Curt but that is the only way to control your fuel and proper fuel managment is part of flying.  General aviation is full of fuel related incidents as well as commerical aviation.  I'm trying to reduce other fuel related problems excessive fuel imbalance can be just as dangerious as fuel starvation.  My thinking on the two fuel selectors at the wing roots is it's very visable (I.E.unlike John Denver's) and easy to get at.



Reguards.  Dave

dwilde(at)clearwire.net
Guest

Posted: Wed Jul 01, 2009 7:11 am Post subject: 701 fuel system design

I just installed valves at each wing root inside the cockpit.  I can 

easily reach each valve and use it to balance fuel use between tanks.  I 

added a note in my preflight checklist to make sure all fuel valves are 

on for takeoff.



Dan Wilde

 	  Quote: 	
		  

 Too true Curt but that is the only way to control your fuel and proper fuel managment is part of flying.  General aviation is full of fuel related incidents as well as commerical aviation.  I'm trying to reduce other fuel related problems excessive fuel imbalance can be just as dangerious as fuel starvation.  My thinking on the two fuel selectors at the wing roots is it's very visable (I.E.unlike John Denver's) and easy to get at.



 Reguards.  Dave

ggower_99(at)yahoo.com
Guest

Posted: Wed Jul 01, 2009 9:23 am Post subject: 701 fuel system design

Hello Dan,

  

 I installed the same (one valve in each side of the cabin).  My 701 with only the main valve (floor valve), will always use first the gasoline from the right wing.  No problem in short flights (less than an hour), when the plane is parked both tanks will even in a few minutes.

  

 In long XCountry flights (more than 2.5 hrs a leg) this has worked for me: 

  

 Take off with both side valves open, for security,  at cruise altitude I close the right tank for one hour (in use the left tank), at one hour, I open the right valve (keep both valves opened for the rest of the flight) and when landing I always land with both tanks (almost) even. 

 For "Simplicity and lightness" I should only add the right wing valve, left one never closed for balance fuel.

  

 I always plan my flights for less than 3 hrs a leg... I get a little nervous when the "trusty" electric needles get close to 1/4...      

 Here there are only a few landing strips, less with gasoline available.

  

 Saludos

 Gary Gower

 Flying from Chapala, Mexico

 

Coordenadas Google Earth.

 20°18'33.86"N 103° 9'36.99"W

 701 912S   251 hrs of fun

 Building a 601 XL Jab 3300.

 

--- On Wed, 7/1/09, Dan Wilde <dwilde(at)clearwire.net> wrote:



  	  Quote: 	
		  

From: Dan Wilde <dwilde(at)clearwire.net>

Subject: Re: Re: 701 fuel system design

To: zenith701801-list(at)matronics.com

Date: Wednesday, July 1, 2009, 11:10 AM



 --> Zenith701801-List message posted by: Dan Wilde <dwilde(at)clearwire.net (dwilde(at)clearwire.net)>



I just installed valves at each wing root inside the cockpit.  I can 

easily reach each valve and use it to balance fuel use between tanks.  I 

added a note in my preflight checklist to make sure all fuel valves are 

on for takeoff.



Dan Wilde

 	  Quote: 	
		  

 Too true Curt but that is the only way to control your fuel and proper fuel managment is part of flying.  General aviation is full of fuel related incidents as well as commerical aviation.  I'm trying to reduce other fuel related problems excessive fuel imbalance can be just as dangerious as fuel starvation.  My thinking on the two fuel selectors at the wing roots is it's very visable (I.E.unlike John Denver's) and easy to get  at.



 Reguards.  Dave



&nNavigator?Zenith701801-List" target=_blank>http://www.matronics.com/Navig========================


	


	


           [quote][b]

dwilde(at)clearwire.net
Guest

Posted: Wed Jul 01, 2009 1:59 pm Post subject: 701 fuel system design

Gary Gower wrote:

 	  Quote: 	
		  

  

 I always plan my flights for less than 3 hrs a leg... I get a little 

 nervous when the "trusty" electric needles get close to 1/4...     

 Here there are only a few landing strips, less with gasoline available.

  



My butt would not hold out for any longer than 3 hours.  I agree when 
	


the needle approaches 1/4 it is time to find some fuel.



Dan Wilde



PS - I made another near perfect landing the other day.  The only thing 

wrong was I was 3 feet over the runway when it stopped flying.

NYTerminat(at)aol.com
Guest

Posted: Wed Jul 01, 2009 4:37 pm Post subject: 701 fuel system design

I have that same set up. I don't have too much of a fuel balance problem  but the best thing about them is if you park on a slant, just shut off one of  the valves and the fuel won't transfer between tanks and siphon out the vent of  the lower tank. Ask me how I know 

  

 Bob Spudis

 N701ZX/ CH701/912S

  

 In a message dated 7/1/2009 11:11:37 A.M. Eastern Daylight Time,  dwilde(at)clearwire.net writes:

  	  Quote: 	
		  -->    Zenith701801-List message posted by: Dan Wilde    <dwilde(at)clearwire.net>



I just installed valves at each wing root    inside the cockpit.  I can 

easily reach each valve and use it to    balance fuel use between tanks.  I 

added a note in my preflight    checklist to make sure all fuel valves are 

on for takeoff.



Dan    Wilde

 	  Quote: 	
		  

 Too true Curt but that is the only way to control your    fuel and proper fuel managment is part of flying.  General aviation is    full of fuel related incidents as well as commerical aviation.  I'm    trying to reduce other fuel related problems excessive fuel imbalance can be    just as dangerious as fuel starvation.  My thinking on the two fuel    selectors at the wing roots is it's very visable (I.E.unlike John Denver's)    and easy to get at.



 Reguards.   Dave



	

	


 

  

 Dell Laptops: Huge Savings on Popular Laptops - Deals starting at $399

  [quote][b]

lgold(at)quantum-associat
Guest

Posted: Sun Jul 05, 2009 11:01 am Post subject: 701 fuel system design

Dave,

Answering your questions:

I don't think there are problems removing the wings with selectors inside

the cockpit at the wing root. Just disconnect the lines to the wings at that

point. Having said this I need to add that I have never disconnected them

and would not recommend this if you plan to remove the wings a lot unless

you put some type of quick disconnect as opposed to just pushing the lines

onto a nipple.

It would be difficult sending pics of my installation. I ran the lines

inside the cockpit from the two selectors down along the steel cage on

either side of the windshield, through the firewall and to a single

gascolator at the lowest point on the firewall. This is the lowest point in

the fuel system and the lines run downhill from the tanks so that water

could not collect anywhere else than the gascolator. From there I ran the

fuel lines up through a fuel flow meter and an aux electric pump (which I

have never had to use) to the engine. I was concerned that putting the

gascolator forward of the firewall could lead to vapor locks.. Not so; I

have 250 flight hours, some of it in 105+ air temps without any problems.

Les

--

lgold(at)quantum-associat
Guest

Posted: Sun Jul 05, 2009 6:10 pm Post subject: 701 fuel system design

Gary,  

If you don’t want to get nervous about your “trusty” electric needles to determine fuel availability, consider a fuel flow measuring system. The fuel flow sensor  added about $100 to the cost of my Dynon engine monitoring. When I fill up now I rarely have to add over a quarter-gallon more or less than the Dynon tells me that I have used.  

Also, we have discussed the uneven draw from the tanks in earlier threads. I always fly with both inner tanks or both outer tanks open so that I can’t forget to switch tanks. My tanks may drain unevenly because my autopilot uses the ailerons to steer the plane, which means the wings are not always level. Frankly I won’t  worry about this unless I’m low on fuel because if one tank empties the plane should just draw from the other one. However,  I have never been really low on fuel and the tanks have never had more than a 4-gallon difference to see what would happen.  

Les       

From: owner-zenith701801-list-server(at)matronics.com [mailto:owner-zenith701801-list-server(at)matronics.com] On Behalf Of Gary Gower

 Sent: Wednesday, July 01, 2009 10:22 AM

 To: zenith701801-list(at)matronics.com

 Subject: Re: Re: 701 fuel system design  

Hello Dan,   

I installed the same (one valve in each side of the   cabin).  My 701 with only the main valve (floor valve), will always use   first the gasoline from the right wing.  No problem in short flights   (less than an hour), when the plane is parked both tanks will even in a few   minutes.   

In long XCountry flights (more than 2.5 hrs a leg) this   has worked for me:    

Take off with both side valves open, for security,    at cruise altitude I close the right tank for one hour (in use the left   tank), at one hour, I open the right valve (keep both valves opened for the   rest of the flight) and when landing I always land with both tanks (almost)   even.    

For "Simplicity and lightness" I should only add   the right wing valve, left one never closed for balance fuel.   

I always plan my flights for less than 3 hrs a leg... I   get a little nervous when the "trusty" electric needles get close   to 1/4...         

Here there are only a few landing strips, less with   gasoline available.   

Saludos   

Gary Gower   

Flying from Chapala, Mexico   

Coordenadas Google Earth.      

20°18'33.86"N 103°   9'36.99"W   

701 912S   251 hrs of fun   

Building a 601 XL Jab 3300.   

   --- On Wed, 7/1/09, Dan Wilde <dwilde(at)clearwire.net>   wrote:   

    	  Quote: 	

   From: Dan Wilde <dwilde(at)clearwire.net>

   Subject: Re: Re: 701 fuel system design

   To: zenith701801-list(at)matronics.com

   Date: Wednesday, July 1, 2009, 11:10 AM      

--> Zenith701801-List message posted by: Dan Wilde <dwilde(at)clearwire.net>

   I just installed valves at each wing root inside the cockpit.  I can 

   easily reach each valve and use it to balance fuel use between tanks.  I   

   added a note in my preflight checklist to make sure all fuel valves are 

   on for takeoff.

   Dan Wilde

   >

   > Too true Curt but that is the only way to control your fuel and proper   fuel managment is part of flying.  General aviation is full of fuel   related incidents as well as commerical aviation.  I'm trying to reduce   other fuel related problems excessive fuel imbalance can be just as   dangerious as fuel starvation.  My thinking on the two fuel selectors at   the wing roots is it's very visable (I.E.unlike John Denver's) and easy to   get at.

   >

   > Reguards.  Dave

   >

   >

   >

   >&nNavigator?Zenith701801-List"   target=_blank>http://www.matronics.com/Navig========================   Navigator Photoshare, and   href="http://www.matronics.com/Navigator?Zenith701801-List">http://www.matronics.com/Navigator?Zenith701801-List Web Forums! href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c  ===========    

       [quote][b]

bobkat

Joined: 07 Sep 2008
Posts: 143
Location: Bismarck, ND

Posted: Mon Jul 06, 2009 4:39 am Post subject: 701 fuel system design

Yes, I'd sure recommend the digital fuel flow  sensor on the Dynon.  When it tells you that you have say, 5.7 gallons on  one tank and 4.3 in the other, it is right on!  Always within a tenth of a  gallon or so.  

 Actually I found my 10 gallon tanks hold close to  11, so when I calibrated it, I put a gallon in them and then 'told' it that  it was empty, etc.  So I have 1 - 2 gallons more than the gauges tell  me.  A bit of a fudge factor.  

 Like Les, I'd highly recommend any fuel flow  meter.  My neighbor has another make on his RV-8 but I don't recll the make  or mode.  

 In the rare instance when you start to get low with  a few gallons in a tank, it will flash and yell at you to remind you to fuel  up.  It does everything to alert you short of a hand popping out of the  Dynon and slapping you on the cheek!  Maybe Les's autopilot grabs the stick  from the pilot and flies to the nearest airport on the GPS database!   Hah!

 [quote]   ---

jetboy

Joined: 22 Jul 2006
Posts: 233

Posted: Fri Jul 10, 2009 12:45 am Post subject: Re: 701 fuel system design

I added some photos of my plumbing here:



http://www.zenith.aero/profile/RalphSanson?xg_source=profiles_memberList

Ralph

_________________
Ralph - CH701 / 2200a

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