Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

CH701 Usable Fuel

Matronics Email Lists Forum Index -> Zenith-List

View previous topic :: View next topic

Author Message

arno7452(at)bellsouth.net
Guest

Posted: Fri Oct 05, 2007 11:49 am Post subject: CH701 Usable Fuel

I am close to finishing my 701.  To measure  usable fuel, I plan to fill the tanks, drain them thru the regular fuel lines  while the plane is sitting on the ground.  Seems this should provide  reasonable estimate of usable fuel.

  

 I would appreciate any values other 701 flyers are  using.

  

 Regards,

 Ken Arnold

 CH701 N701LK 90%

   [quote][b]

n85ae

Joined: 14 Mar 2007
Posts: 403

Posted: Fri Oct 05, 2007 11:55 am Post subject: Re: CH701 Usable Fuel

One thing to consider is the pitch attitude of the plane in a climb/descent,

and make concession for the fuel level other than level flight. You might

find that due to do the pickup location you have a couple gallons less

usable fuel than what you have when level.



Basically, your engine can quit in climb or descent, do to the pickup 

being exposed (i.e. gas all at the other end of the tank.).



Regards,

Jeff

shilcom

Joined: 28 Sep 2007
Posts: 63

Posted: Fri Oct 05, 2007 5:27 pm Post subject: CH701 Usable Fuel

Should consider all expected attitudes, especially  steep descent and departure climb.  Bob U. 

 [quote]   ---

Terry Phillips

Joined: 11 Jan 2006
Posts: 346
Location: Corvallis, MT

Posted: Fri Oct 05, 2007 7:07 pm Post subject: CH701 Usable Fuel

Ken



 I recommend that you consider the approach suggested by John Deakin in Pelican's Perch #7. Basically, he recommends determining the usable fuel in each tank experimentally, while flying a variety of "maneuvers." Unfortunately, the net link that I have for that article



 www.warmkessel.com/jr/flying/td/jd/7.jsp 



  seems to be broken when I just tried it. The article is available in the Google cache. Or, let me know if you would like me to send you a pdf.



 Terry



 

 At 03:44 PM 10/5/2007 -0400, you wrote:

  	  Quote: 	
		  I am close to finishing my 701.  To measure usable fuel, I plan to fill the tanks, drain them thru the regular fuel lines while the plane is sitting on the ground.  Seems this should provide reasonable estimate of usable fuel.

  

 I would appreciate any values other 701 flyers are using.

  

 Regards,

 Ken Arnold

 CH701 N701LK 90%

 	
 

 

 Terry Phillips

 ttp44~at~rkymtn.net

 Corvallis MT

 601XL/Jab 3300 slow build kit - Rudder done--finally; working on the stab

 http://www.mykitlog.com/N47TP/    [quote][b]

_________________
Terry Phillips
Corvallis, MT
ttp44<at>rkymtn.net
Zenith 601XL/Jab 3300 slow build kit - Tail feathers done; working on the wings.

craig(at)craigandjean.com
Guest

Posted: Fri Oct 05, 2007 9:01 pm Post subject: CH701 Usable Fuel

>  I recommend that you consider the approach  suggested by John Deakin in Pelican's Perch #7. 

  

 This  link is good but you have to do a (free) registration:

  

 http://www.avweb.com/news/pelican/182044-1.html

  

 --  Craig 

   [quote][b]

jetboy

Joined: 22 Jul 2006
Posts: 233

Posted: Sat Oct 06, 2007 12:37 am Post subject: Re: CH701 Usable Fuel

I calibrated my dipstick for 'drainable fuel'   so when I dip the tanks I know how much  fuel is available in a level flight attitude.



For the CZAW tanks that works out about 40 litres / side with 2.5 litres undrainable - total rating for these tanks was 85 litres.



As with most aircraft, Cessna 150 for example, there must be an additional amount of fuel available to slosh about and still maintain safe flight and the proper term for this may well be 'unuseable fuel'



For the CZAW tanks I rate that amount as 10 litres / side.



I have at times unported a tank with 15 litres when in a steep descent, resulting in power loss of 10 - 30 seconds, so the problem is real. I have not had any problems in level or climbing flight but the drill is to feed off a better tank or both if the level is low.



Ralph

_________________
Ralph - CH701 / 2200a

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Sun Oct 07, 2007 12:17 pm Post subject: Re: CH701 Usable Fuel

Has anyone used a 3rd smaller tank in the fuselage, by plumbing both wing tanks to it and the plumbing this to the engine? It would only take a couple of gallons or less. And if you made the tank tall and narrow and place the outlet on the bottom, then most maneuvers would not effect fuel flow. 



Kevin

_________________
“Always do what you are afraid to do.”
R.W. Emerson (1803-1882)

"Real freedom is the sustained act of being an individual." WW - 2009

"Life is a good deal...it's worth it" Feb 1969
Dorothy McCune

jetboy

Joined: 22 Jul 2006
Posts: 233

Posted: Mon Oct 08, 2007 1:43 am Post subject: Re: CH701 Usable Fuel

Thanks kevin,



 if I was doing it again I would probably construct an extra tall ZAC gascolator. The drawings call for the gascolator(s)  - two for the long range tanks option - to be fabricated from a rectangular section aluminum extrusion with end caps welded top and bottom. Would need to fit the outlet at the normal standoff distance from the drain valve.



 Because my aircraft didnt come with the gascolator parts I purchased an ACS one with mesh filter



Ralph

_________________
Ralph - CH701 / 2200a

river1

Joined: 07 Sep 2007
Posts: 28

Posted: Mon Oct 08, 2007 2:14 am Post subject: Re: CH701 Usable Fuel

Kevin ; The early 701 had that option , it was called "D" tank . It was used in Conbination with the then optional wing tanks and allowed space for avionics.                          	  kmccune wrote: 	
		  Has anyone used a 3rd smaller tank in the fuselage, by plumbing both wing tanks to it and the plumbing this to the engine? It would only take a couple of gallons or less. And if you made the tank tall and narrow and place the outlet on the bottom, then most maneuvers would not effect fuel flow. 



Kevin

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Oct 08, 2007 4:05 am Post subject: Re: CH701 Usable Fuel

I had heard that they came with a cowl tank, is this the same or did the cowl tank get replaced by wing tanks. Sorry, just trying to get it straight.



 Any idea how much the D tank held?

Kevin

cgbrt(at)mondenet.com
Guest

Posted: Mon Oct 08, 2007 4:36 am Post subject: CH701 Usable Fuel

Kevin.

I installed an 8 litre collector behind the baggage compartment four years

ago. Both wings feed through the collector. It is tall and narrow with a

gascolator on the bottom that drains through the bottom fuselage skin.

A float sensor in the top lights a low fuel warning  as soon as the fuel

level starts to go down in the collector giving me a no s--- 30 minute

reserve. I also have a vertical sight gauge with a black cork float to make

it easier to read.

It works well and I can safely burn the wing tanks dry without fuel feed

interruption to the Rotax 912.

Carl

701 on amphibs 476 hrs.

---

river1

Joined: 07 Sep 2007
Posts: 28

Posted: Mon Oct 08, 2007 4:52 am Post subject: Re: CH701 Usable Fuel

Hi Kevin ; No it was a separate option when you wanted either more range or space for avionics. I have parts of a 1990 info pack , it doesn't say how many gal the D tank had , maybe zac has option drawings for that .

arno7452(at)bellsouth.net
Guest

Posted: Mon Oct 08, 2007 2:02 pm Post subject: CH701 Usable Fuel

Thanks for all the good comments.  It appears  the 701 has a little over 20gal of usable fuel.  Installing a "D" tank is  more than I want to tackle.  It appears to have merit and adds another  level of safety.

  

 Another suggestion is to install individual fuel  cutoffs on the two tanks.  Run one dry and then quickly turn the other  on.  Not sure if intentionally stopping the engine while airborne is a good  idea.

  

 Regards,

 Ken Arnold

 CH701  N701LK 91%

  

  

  

  

 [quote]   ---

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Oct 08, 2007 6:05 pm Post subject: Re: CH701 Usable Fuel

Actually my idea, which apparently is NOT new    was to get  a bit more range cheaply. The safety factor is just a welcomed by-product.  



Hope it all works out well for you. 



Kevin

NYTerminat(at)aol.com
Guest

Posted: Mon Oct 08, 2007 6:38 pm Post subject: CH701 Usable Fuel

I installed a valve at each wing root to be able to  shut off each tank. If you have an imbalance you can burn off the higher tank  and shut off the lower one. This does not happen often but the real plus of  having the valves is when you park at an uneven slope you can prevent the one  tank siphoning into the other and then flowing out of the tank vent. I have  found this invaluable. I got this suggestion from Gary in Mexico. Thanks Gary,  works great!!!!

  

 Bob Spudis

 N701ZX  CH701/912S/138 hrs

  

  

  

 In a message dated 10/8/2007 6:04:22 P.M. Eastern Daylight Time,  arno7452(at)bellsouth.net writes:

  	  Quote: 	
		     Thanks for all the good comments.  It    appears the 701 has a little over 20gal of usable fuel.  Installing a "D"    tank is more than I want to tackle.  It appears to have merit and adds    another level of safety.

    

   Another    suggestion is to install individual fuel cutoffs on the two tanks.  Run    one dry and then quickly turn the other on.  Not sure if intentionally    stopping the engine while airborne is a good idea.

    

   Regards,

   Ken Arnold

   CH701  N701LK 91%

    

    

    

	


 

  



See what's new [quote][b]

milreed(at)wildblue.net
Guest

Posted: Wed Oct 10, 2007 12:20 pm Post subject: CH701 Usable Fuel

Kevin

 Gordon Poer has a small tank behind the seat  on the right side of his 701. He runs a  85 HP Continental for  power. 

 When he first flew the craft he did so with gravity  feed only from the wing tanks down behind the seat to the floor. During  some moderate maneuvers he got an air lock in the line and resultant engine  failure. I was just looking at his new setup at the Placerville airport  last week.

 Now he has a mechanical and electric fuel pumps as  well as that small aux tank which is supplied by the right wing tank only. No  more fuel problemos !

 Mil

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Wed Oct 10, 2007 3:54 pm Post subject: Re: CH701 Usable Fuel

I like the shut off vale idea, makes take off a little less exciting! 



I knew that I needed a fuel pump as the outlet would have to be almost level with the engine.  Why doe it feed off of only one of the wing tanks?



I also have learned that the guy with the Hawg-Air site (Hog-Air?) has 14 gallon wing tanks for sale. Now I still like the stock  aluminum ones... but they could be larger, say 12 gallons each. 



Kevin

Display posts from previous:

	Matronics Email Lists Forum Index -> Zenith-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum