Fuel tank venting.

[Buzzfagan]

I have been reading a bunch of threads and post and cannot seem to find the right answer for my question. Could you please give me some advice?

I am about to start making my fuel tank adjustments and am trying to decide between just doing a vented cap or running a separate vent out of the neck and using some fuel line or something to run it down under my buggy.

Would it still vent properly/flow if I had the separate vent line running down under the vehicle?

Would it help with the fume smells in the cockpit rather than just a vented cap? Are there any other advantages to doing it this way?

Should I go with both the separate vent tube and the vented cap or just the separate line and a non vented cap?

Do you have to worry about spiders/webs or other critters climbing up into the separate vent tube if it is leading under the car? How would you be able to tell if that happened?

Once I do either method do I seal shut ALL other manufactured holes on the tank?

I forgot to mention this. The way my hood is set up I have a large hole that a cover must go over. So I am planning on having some kind of flip up lid assembly mounted to the hood that is not attached to the neck at all. All it is doing is covering the the hole in the hood and providing access to the neck and actual fuel cap. So I will have to first open that outer covering to get to the actual screw off fuel cap.

Will that still work?

Will the tank and fuel cap still vent under a closed hood if I did not use the additional vent line?

If it does, will the fumes be smelt while in the car with just a vented cap under the cover in the hood.

What is best to do?

Please see pictures:

-there is one photo of my hood with the large hole
-two of the components I am planning on buying, one for the cover in the hood and one for the neck and actual fuel cap
-the last one is an an example I saw somewhere at a VW/buggy show but did not ask about all the details on it at the time

[boltman]

Hi Buzz:

I have a manx style buggy with a vw tank in the front and the filler cap at the left front of the tank by the headlight. I had a small hole drilled in the cap for a vent. If I filled the tank over 2/3 full, and turned hard to the right, I would get a very light spray of gas across the hood and windshield and gasoline smell that lingered for some time.

I recently had the hood off and decided to put an inverted flare in the top back of the tank on the passenger side. I took a 3/16 steel brake line and put a double loop just above the tank and routed it out beside the firewall and just below the car. I sealed the gas cap vent hole. After filling the tank to the top of the neck I thought everything was fixed.....till I took a hard left turn. It still loses a small amount of fuel out the overflow and even though the gas goes under the car I get a brief faint gas smell.

This is not perfect, and I can smell gas occasionally in the garage but I suppose I will live with it for now. I think there is probably a better fix for this but wanted you to know what my experience was.

Good Luck
Keith

[Buzzfagan]

Thanks for the reply. I really appreciate you sharing that. I also updated my post with some other descriptions and photos.

[Bill K]

I vented mine off the filler neck and ran tubing down and under the chassis. It's works great.

[staggerwing]

Same here.