Vented Fuel Tank

[brainbug007]

So I got one of these http://www.ebay.co.uk/itm/Fuel-Tank-...item336841c136 inbetween the tank and the pump. This may seem a bit thick but how does this vent the pressure in the tank as it will always have fuel in it? Does it just let some of the fuel leak out to relieve the pressure?

[mark]

Originally Posted by brainbug007

So I got one of these http://www.ebay.co.uk/itm/Fuel-Tank-...item336841c136 inbetween the tank and the pump. This may seem a bit thick but how does this vent the pressure in the tank as it will always have fuel in it? Does it just let some of the fuel leak out to relieve the pressure?

It should be mounted to an outlet on the top of the tank then to atmosphere, so air can get in but fuel cant get out

Ideally it should be two way to let pressure out when its hot too, but seal in the event of a roll (as in davidmurrays link)

[brainbug007]

Ok thanks mark.

[davedew]

Out of interest do you actually need on of these valves? I can't recall seeing in the iva manual anything about one way valves.

I know the tank needs to be vented. If you took a hose from the top of the tank to below the bottom of the tank, if the car was upside down the bottom of the hose becomes the highest point and the tank won't empty anyway.

I know it doesn't work if the car ends up on it's side, but if you manage to end up upside down, or on your side you'll be in a pretty bad state / dead I would imagine.

[brainbug007]

Lol encouraging dave! Personally I'm not worried about the shutoff side of this, like you said there's not requirement from an iva standpoint. I was just after a cheap and simple way to vent it.

[mark]

Originally Posted by davedew

Out of interest do you actually need on of these valves? I can't recall seeing in the iva manual anything about one way valves.

I know the tank needs to be vented. If you took a hose from the top of the tank to below the bottom of the tank, if the car was upside down the bottom of the hose becomes the highest point and the tank won't empty anyway.

I know it doesn't work if the car ends up on it's side, but if you manage to end up upside down, or on your side you'll be in a pretty bad state / dead I would imagine.

This is how i did mine, cheap but works

You need a long length of hose though and take it as high up as possible as it can siphon out during extreme cornering with a full tank

I ended up putting a cheapy transparent fuel filter in the line to act as a trap and its never happened since