huck1199

Where do people run the vent line to? I assume some gas will leak out during some manuevers. Should the end of the vent be up or down?

Thanks

STUKA BARRY

Have it pointing down thru the cowl. You will see a trickle of fuel when the tank is full, or a steady sream if your not paying attention.

Tired Old Man

My Feedback: (1)

Right out the bottom of the plane, ahead of or behind the landing gear.

huck1199

Thanks Guys.  Down it is.

BarracudaHockey

My Feedback: (11)

Run a loop horizontally around the tank then out the bottom. That will minimize any leakage unless you're filling the tank.

huck1199

Andy

I like that idea, will do. Thanks

Tired Old Man

My Feedback: (1)

A waste of perfectly good Tygon

huck1199

TOM

It won't help??

aussiesteve

Many make a loop that goes from the front of the tank to behind and above the tank, then forward and down below the tank to exit out the bottom of the fuse.

I used to do it that way also but as T.O.M says it is a waste of good tygon.

Now I make a loop that goes from the front of the tank to above the tank then down and below the fuse.

IF you do VERY long downlines the former method will stop some fuel dripping from the tank but the amount is absolutely negligible due to the lower pressure in the tank during engine operation. In reality, for about 99% of fliers, there is no loss of fuel by using the latter method. Out of curiosity, I tried it once with some UV active dye added to my fuel to see if I could see any splatter on the fuse (under UV light) - I found none by using the second method (but the white covering showed up very nicely under that light).

rangerfredbob

My Feedback: (13)

That's why I use cheaper Nylon line for the vent on my planes...

Zeeb

My Feedback: (41)

The vent line on my Comp-Arf exits the bottom of the fuselage behind the tank since things were getting crowed up front. I tried it without running a loop and had gas siphoning out of the vent a bit even during initial ground runs and it was much worse after the Maiden flight, so I put the loop around the top of the tank and presto, problem solved.

huck1199

Loop it will be. Will use cheap silicon line. Thanks guys - very good info.

I got stung at the LHS, I bought aDubro gas tank conversion kit for my24oz tank and found that the brass tubes are 1/8";not 3/32". So I will have to get larger tubes and modify it. $5 for a plug and screw is a waste.

rangerfredbob

My Feedback: (13)

DO NOT USE SILICONE FUEL LINE, it will last 5 minutes before it goes away... go to the hardware store and get the clear line for $.25/foot if you want something cheap. It will harden but not get brittle.

1/8" tubes are fine as long as the tubing fits tight on the outside

huck1199

The tygon I have is 5/32, so I need a larger tube for the fuel feed line.  I meanr 5/32" in the previous post, my error. 

Tired Old Man

My Feedback: (1)

An FYI.

One size fits just about everything. 1/8" i.d. Even a 150cc engine will run fine with as small as 3/32'.

MetallicaJunkie

thats good to know!