What do people recommend, have used etc for the air admittance valve on their fuel tanks?

Cheers,

The Baron

Thinkautomotive sell a range of valves that close if the car is inverted.
If you have any form of fuel return, especially on an injection set up, you will need a valve that breathes in and out.
You can also create an "S" bend in some fuel hose that will act as a breather but will also prevent fuel from coming out if you turn the car upside down
I made the mistake of only using a one way valve and the return fuel pressurized my tank. I am now using a two way one with no problems.

[Edited on 8/7/2007 by nitram38]

Demon tweeks (£££) hold some nice aluminium ones, think mine cost me £20. I then hooked it up to some fuel pipe and as said above looped it round 3 times to really make sure no leaks would happen if it rolled. Basically it looks like a ball bearing inside i turned bit of aluminium which is 'open. when upright, but closes when inverted.

You could of course go the free way, an old servo valve, the lump that the tube plugs into.

These will pass MSA for racing, designed to sniff fuel and not fall apart !

Cheers Mark

I didn't want to pay Demon Tweeks money, nor could I be arsed to go to a scrappies for a miniscule part, so I went o a pet shop and got a fish tank valve, it cost £1.99!

On top of this though I would fit a second fuel line through the car because you don't know what modifications may occur in the near or distant future!

Steve

Whatever you use it really has to be a two way valve. Air needs to escape due to expansion and also needs to be sucked in to replace the fuel is used. That is why the breathers which are stocked by Think Auto, Demon Tweeks etc seem very expensive.

I once saw a Mini fuel tank that imploded due to a blocked tank breather - its amazing how powerful a fuel pump can be!

I used an old Mini filler neck cut off the tank and fastened to my home made tank. Mini filler caps are vented