 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
MHerder
Joined: 11 Feb 2008
Posts: 143
Location: Fort Worth TX
|
 Posted: Fri Jan 29, 2010 2:26 pm Post subject: Fuel System Questions |
 |
|
Background: I have used soft aluminum fuel tubing from each of the wing tanks in my 601 HD. I never really liked the idea of using rubber tubing near me or passengers. Fuel scares me, and it really scares me in a plastic bubble at 5000 ft. I went to great lengths to make sure that I only have fittings where absolutely necessary as I view them only as a potential source of leaks. I have used AN 6 fittings throughout which has turned out to be considerably more work and more expensive than I could have imagined but I’m still not unhappy with my decision… However I have several questions from the firewall foreward.
1) I have used an AN bulkhead fitting to get through the firewall, and I am using AN fittings to attach to my Facet fuel pump, what type of hose can and should be used for a custom length fabrication of fuel hose that can be properly firesleeved? Any good sources?
2) Once I get to the other side of the fuel pump (outlet side), it looks like I’ll have to switch over to the barbed fuel fittings, since that is what is on my Bing carb anyway (Jab 3300). Is there a suggested way to safety wire the radiatior hose type clamps?
3) I’m using a facet pump, mounted on the front side of the firewall in series with the mechanical pump on my Jab 3300. I have been told, and seen tests verifying that indeed, if the facet pump fails that fuel can still be drawn through the electric pump. In fact the current plan would be that I would only use the electric pump during takeoff and landing so it would nearly always be drawing fuel through this pump. As I understand it, this is acceptable, but I’d like a confirmation from somebody that it doesn’t put undue stress on the mechanical pump and potentially make it wear out quicker.
Lots of questions here and I’m sure there will be lots of opinions. I want to be absolutely certain that I do the fuel system right, also everything else… But fuel is certainly one of my greatest concerns, along with the obvious things like control rigging etc.
| | - The Matronics Zenith601-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith601-List |
|
_________________
Zodiac 601 HD
Jabiru 3300
Wood Sensinich 64x47
Finally Flying |
|
| Back to top |
|
 |
daveaustin2(at)primus.ca
Guest
|
| Posted: Fri Jan 29, 2010 3:06 pm Post subject: Fuel System Questions |
|
|
If you put the fuel pumps in series, will that not double the pressure at
the carbs? If you do you could have flooding problems.
Dave Austin 601HDS 912UL
| | - The Matronics Zenith601-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith601-List |
|
|
|
| Back to top |
|
|
larry(at)macsmachine.com
Guest
|
| Posted: Fri Jan 29, 2010 3:13 pm Post subject: Fuel System Questions |
|
|
Michael,
I'd recommend Aeroquip 601 with fittings or 666. Both have a very
protective braid externally and are made for fuel. The fittings and hose
are expensive, but
best suited to your need. I've a water cooled engine and the temps don't
get high enough to worry about the filter and hose seen on my firewall,
but I did use
the hose where it tee'd to the Bing carbs. See image links,
http://www.macsmachine.com/images/subaruengine/full/hose-connections-at-water-p.gif
http://www.macsmachine.com/images/subaruengine/full/hose-reservoir-to-left-fire.gif
http://www.macsmachine.com/images/subaruengine/full/pump&gascolator.gif
Ultimately I put 2 pumps parallel tee'd on a similar plate same place
and doubled back to go up to the short hose and filter that I change
annually.
As long as your pulling thru the pump, the mechanical pump won't be
stressed, but pulling fuel any long distance will get you into trouble
if the pull is negative or less than positive if heat is a factor.
Larry McFarland 601HDS at www.macsmachine.com
MHerder wrote:
| Quote: |
Background: I have used soft aluminum fuel tubing from each of the wing tanks in my 601 HD. I never really liked the idea of using rubber tubing near me or passengers. Fuel scares me, and it really scares me in a plastic bubble at 5000 ft. I went to great lengths to make sure that I only have fittings where absolutely necessary as I view them only as a potential source of leaks. I have used AN 6 fittings throughout which has turned out to be considerably more work and more expensive than I could have imagined but I’m still not unhappy with my decision… However I have several questions from the firewall foreward.
1) I have used an AN bulkhead fitting to get through the firewall, and I am using AN fittings to attach to my Facet fuel pump, what type of hose can and should be used for a custom length fabrication of fuel hose that can be properly firesleeved? Any good sources?
2) Once I get to the other side of the fuel pump (outlet side), it looks like I’ll have to switch over to the barbed fuel fittings, since that is what is on my Bing carb anyway (Jab 3300). Is there a suggested way to safety wire the radiatior hose type clamps?
3) I’m using a facet pump, mounted on the front side of the firewall in series with the mechanical pump on my Jab 3300. I have been told, and seen tests verifying that indeed, if the facet pump fails that fuel can still be drawn through the electric pump. In fact the current plan would be that I would only use the electric pump during takeoff and landing so it would nearly always be drawing fuel through this pump. As I understand it, this is acceptable, but I’d like a confirmation from somebody that it doesn’t put undue stress on the mechanical pump and potentially make it wear out quicker.
Lots of questions here and I’m sure there will be lots of opinions. I want to be absolutely certain that I do the fuel system right, also everything else… But fuel is certainly one of my greatest concerns, along with the obvious things like control rigging etc.
--------
One Rivet at a Time!
|
| | - The Matronics Zenith601-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith601-List |
|
|
|
| Back to top |
|
|
mhubel
Joined: 05 Sep 2009
Posts: 141
|
| Posted: Sat Jan 30, 2010 6:33 am Post subject: Re: Fuel System Questions |
|
|
Your installation sounds very much like mine. I also used aluminum tubing with AN6 fittings for everything aft of the firewall. I did have a few more fittings than you are describing as this includes a fuel selector and a union in each line going to the wing. The union was required to make it possible to get the line in with the wing in place.
I can't stand barbed connections for almost anything in an aircraft. We are forced to use them in boats and I don't like them there either. I have seen hose slowly fail under the clamps. To make things much worse, the bing design forces a sharp bend in the hose just as it comes off the nipple. This is an absolute no-no in hose assembly even where barbed hoses are considered acceptable.
Given the thread size on the facet fuel pump, I didn't fight it and used AN5 size hose from the facet pump to the 3300 pump and from there to the carb. You could use AN6 hose, the 1/8" to AN6 fittings exist, they are just not as common.
The hose used everywhere is pre made Aeroquip AE466 with a firesleve molded in. It has a very long life (probably longer than your airplane) but is expensive. This is available from Aircraft spruce and will be $60-100 each depending on length. The catalog part number is AE3663161FXXXX for -5 size or AE3663161GXXXX for -6. This does not show up online but it is a custom order so you need to call them on the phone anyway.
I modified both the carb, a bing, and the 3300 pump to take a threaded fitting for all hoses. The pump is easy, one drills out the existing hole and tapes it with a 1/8 inch pipe tap (of course one dis-assembles the pump to do this). The carb is a bit more difficult. A new fitting is soldered on top of the existing nipple. Pictures of all this are on photo.hubbles.com
Finally, I gave up on the bing and put in a Rotec. I do have the modified Bing. I was planning on selling it once I get the plane flying again after the CH601XL "upgrade".
The Facet pump is a flow through pump. It will allow fuel to flow with no power applied when pumped by the 3300 engine pump. The way these pumps are made pressure seen at the carb is the highest of the pressure either pump can produce, not the sum. Thus it is safe to have both pumps on in series with the Bing carb, if anything is safe with a Bing.
| | - The Matronics Zenith601-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith601-List |
|
_________________
Mark Hubelbank
N708HU
CH601XL
Jabiru 3300
Rotec TBI 40-3 carb
Sensenich ground adj prop.
240 hr TAF
Pictures at photo.hubbles.com |
|
| Back to top |
|
|
|
|
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
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
