Vent line- a different way

RV7Guy · #1 07-07-2008, 03:16 PM

Some time back I remember seeing where some people had coiled the vent line tubing and kept it in the wing root area. The vent fixture was attached to the wing root fairing. It looks like a simpler alternative to the traditional run.

Anyone have information on this method?

n5lp · #2 07-07-2008, 03:19 PM

Quote:

Originally Posted by RV7Guy

Some time back I remember seeing where some people had coiled the vent line tubing and kept it in the wing root area....Anyone have information on this method?

http://www.vansairforce.com/communit...iled+vent+line

Rockyjs · #3 07-07-2008, 07:43 PM

Darwin,
I installed the fuel vents similar to the Rocket method. Due to the shorter skin overhang I riveted a piece of 063 for mounting the bulkhead vent fitting. I then drilled a clearance hole in the root fairing that goes over the vent. This allows the fairing to go on and off without having to disconnect the vent. If you do this I recommend temporarily attaching the fairing first to find where the holes lie and locatie the vent between attach points. I also drilled a # 60 hole in the top of the coil nearest to the fuel vent to act as an alternate air source in the event the vent became obstructed. I haven't flown yet, but have had the tanks full of fuel and run the engine. The vents work fine.

RV7Guy · #4 07-07-2008, 11:56 PM

Hi Rocky,

Thanks. This was exactly what I was looking for. Nice tip on have a secondary mounting flange. I'm going to do it this way.

pierre smith · #5 07-08-2008, 05:37 AM

.....much sooner this way. Van raises the top arc of the lines much higher his way. When you fill the tanks in the sun it will start dripping very shortly afterwards.

Van's way has the top of the vent line 18" higher than the coils.

Regards,

DGlaeser · #6 07-08-2008, 08:07 AM

Quote:

Originally Posted by pierre smith

.....much sooner this way. Van raises the top arc of the lines much higher his way. When you fill the tanks in the sun it will start dripping very shortly afterwards.
Van's way has the top of the vent line 18" higher than the coils.
Regards,

I did mine this way and haven't had a drip yet - with temps into the 90's and full tanks.

captainron · #7 07-08-2008, 09:15 AM

Seems like a way to have some gummy old fuel remaining in the vent coils forever, though I could be wrong.........

DGlaeser · #8 07-08-2008, 09:33 AM

Quote:

Originally Posted by captainron

Seems like a way to have some gummy old fuel remaining in the vent coils forever, though I could be wrong.........

Since the vent line is where the air comes from to replace the fuel being used, they will clear out every time you run on that tank.

rocketbob · #9 07-08-2008, 09:51 AM

How about a check valve like the Lancair's use? Makes for a tidy installation, no coil of tubing to deal with. There's only a little dribbling when the tanks are full since the only fuel that can pass thru the check valve is thru the .040" bleed hole in the check valve's flapper door.

f1rocket · #10 07-08-2008, 11:19 AM

I posted some pictures of my install in the original thread. I thought folks would like an update after 200+ hours of using this installation.

It does run minor amounts of fuel out the vent when full and it's hot. Pierre is correct, at least for my installation anyway. Bob is also correct, I think some small check valves are in order here to cut the amount of drip down.

Overall, the amount of fuel is not that bad but can be noticable on a hot day, maybe a fuel tester cup's worth. However, I like the install better than running the lines up the side of the cockpit so I am willing to live with it.