Fuel tank and venting

For general discussion of the Just Aircraft family of aircraft.
Includes: Highlander, Escapade, Summit and SuperSTOL.
User avatar
BucF16
Veteran Member
Posts: 463
Joined: Sun Mar 23, 2014 11:47 am
Location: Alexandria, Ohio

Re: Fuel tank and venting

Post by BucF16 »

Clark, Mine is like John Nealson's . Mine is Highlander 393. Fiberglass tanks. I followed the directions that Dane described. I just checked the flow through my vents and they were acceptable. So I'm not shitting myself over this issue. I assume Shawn tase the AL tanks with the Citabria type caps. Maybe they are not venting correctly???

Cheers,
Bruce
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Fuel tank and venting

Post by BDA »

Cap I am using

Yes aluminum tanks

I cannot blow through the holes
You do not have the required permissions to view the files attached to this post.
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
mac
Seasoned Member
Posts: 60
Joined: Sun Jul 29, 2012 7:57 pm
Location: Grass Valley, CA.

Re: Fuel tank and venting

Post by mac »

1EA457FA-C09C-4655-8E27-106FD80348BC.jpeg
The picture is the underside of one of my SS “vented” cap. Note the small dent in the inside of the cap. A small slot or hole should be there. It is in the other side. Two small slots or holes should exist. On mine, only one made it through the manufacturing process. Per Jack, I’ll use a #40 drill and create the hole, probably putting some grease on the bit to eliminate excess metal filings.

Will check the other tank tomorrow. Ran out of time tonite. Will report back.

Yes, I have noticed an imbalance in my tanks when flying.
You do not have the required permissions to view the files attached to this post.
Mark M.
N49SS in Phase 2....for good!
User avatar
mac
Seasoned Member
Posts: 60
Joined: Sun Jul 29, 2012 7:57 pm
Location: Grass Valley, CA.

Re: Fuel tank and venting

Post by mac »

109B03B1-AFA2-4AC4-B699-B70291B8FA35.jpeg
Found both caps with only one small slot for venting. Drilled out the other side with a 5/64” drill bit. Didn’t grease the bit. Just blew the crap out of it! See pic. Discussed again with Just. This is essentially what they recommended.
You do not have the required permissions to view the files attached to this post.
Mark M.
N49SS in Phase 2....for good!
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Fuel tank and venting

Post by BDA »

Did you drill the vent holes on the outside edge too??

I am assuming the problem is that there is no venting from inside holes to the outside holes.
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
Tralika
Veteran Member
Posts: 385
Joined: Thu Oct 08, 2009 12:49 pm
Location: Wasilla Alaska

Re: Fuel tank and venting

Post by Tralika »

My Highlander does not feed fuel evenly from both tanks. The left tank empties first. Both fuel caps are vented the same way and I can't tell any difference in the resistance when blowing air through them. I've flown other planes that fed unevenly, it's not really a problem, just a distraction and annoying. In other planes it made me check the fuel selector valve over and over. Don't have that problem with the Highlander.
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
Clark in AZ
Veteran Member
Posts: 356
Joined: Wed Oct 07, 2015 11:40 am
Location: Cave Creek, AZ

Re: Fuel tank and venting

Post by Clark in AZ »

Tralika wrote:My Highlander does not feed fuel evenly from both tanks. The left tank empties first. Both fuel caps are vented the same way and I can't tell any difference in the resistance when blowing air through them. I've flown other planes that fed unevenly, it's not really a problem, just a distraction and annoying. In other planes it made me check the fuel selector valve over and over. Don't have that problem with the Highlander.
Do you have one or two header tanks? If one, do you have a vent line going from the header to one tank? If two, do you have a vent line from each header to each tank (one per side)? Just curious...

Clark
Building SuperSTOL Kit 512
Cave Creek, AZ
User avatar
Tralika
Veteran Member
Posts: 385
Joined: Thu Oct 08, 2009 12:49 pm
Location: Wasilla Alaska

Re: Fuel tank and venting

Post by Tralika »

I have one header tank, about 2.5 gallon mounted on the right side of the baggage area. I flew it for many hours with no fuel vent, then installed a vent from the header to the right tank. The vent made no difference on the way the left fuel tank empties before the right fuel tank.
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
User avatar
mac
Seasoned Member
Posts: 60
Joined: Sun Jul 29, 2012 7:57 pm
Location: Grass Valley, CA.

Re: Fuel tank and venting

Post by mac »

Shawn: I only drilled through the inside alum skin. It appears the vent path to the 4 “outside” vent holes, those holes outside the circular seal ring, were sound.

If I had it to do all over again, I’d figure out a way to vent the header tank. At this point, quite a pain, since I’d rather fly! Not sure it would solve all the flow imbalance problems, but seems reasonable. Maybe a winter project!

Will be flying later this week and see if any improvement with what I’ve done.
Mark M.
N49SS in Phase 2....for good!
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Fuel tank and venting

Post by BDA »

I drilled out the vents around the sides of the caps, i can blow air through now. But the caps are so tight on the tanks that I wonder if they are deforming enough to block the vents.
Will try them out tomorrow.
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
BucF16
Veteran Member
Posts: 463
Joined: Sun Mar 23, 2014 11:47 am
Location: Alexandria, Ohio

Re: Fuel tank and venting

Post by BucF16 »

Shawn, I'm going to HiJack your thread a little bit. :oops:

SO, I haven't vented my 5 gallon header yet. I have fiberglass wing tanks. I really don't want epoxy a bung and then drill and tap both the bung and tank. Debris from drilling could get in the tank, The bung could some day detach itself..........

What do you all think of a vent (like the ones used on the fuel caps) attached to the butt rib. Much like the pitot is attached to the wing rib?

Thanks in advance!

Cheers,
Bruce
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
User avatar
danerazz
Veteran Member
Posts: 1240
Joined: Tue Aug 18, 2009 9:33 pm
Location: Bangor

Re: Fuel tank and venting

Post by danerazz »

I epoxied an an-nipple into the tank end on the right wing tank for a header vent. I put a vacuum at the point that I drilled and tapped the fiberglass, I think it got most of the debris. Then I mixed some west system epoxy and coated everything (nipple threads and inside the hole in the tank) and then mixed som flocked cotton into the remainder of the resin and built a fillet around and under the hex and tightened the nipple. Pretty easy, only took about 30 minutes plus cure time.
Dane

Paralysis by analysis
#242
User avatar
CanadianSheepHunter
Veteran Member
Posts: 678
Joined: Thu Feb 26, 2015 1:05 pm

Re: Fuel tank and venting

Post by CanadianSheepHunter »

Tralika wrote:I have one header tank, about 2.5 gallon mounted on the right side of the baggage area. I flew it for many hours with no fuel vent, then installed a vent from the header to the right tank. The vent made no difference on the way the left fuel tank empties before the right fuel tank.
I spoke with a guy recently that has a SS he didn't build but he feels the length of line from wing tank to header tank(supply to header tank) must be the same length for each wing. Does that make sense to anyone? He also has forward facing 90 degree candy canes on his wing tank fuel caps.

Im still building so i want to know how to solve this.
User avatar
CanadianSheepHunter
Veteran Member
Posts: 678
Joined: Thu Feb 26, 2015 1:05 pm

Re: Fuel tank and venting

Post by CanadianSheepHunter »

This is one of my fuel caps on my SS. The one hole is there...the other hole is not there. I will drill out now, thanks guys! I’m still building. The top pic is the the one with the hole, the other two pics showing the spot that should have a hole.
You do not have the required permissions to view the files attached to this post.
User avatar
CanadianSheepHunter
Veteran Member
Posts: 678
Joined: Thu Feb 26, 2015 1:05 pm

Re: Fuel tank and venting

Post by CanadianSheepHunter »

Here is my other fuel cap, it has both holes open.
You do not have the required permissions to view the files attached to this post.
Post Reply

Return to “Just Aircraft”