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Fuel tank breather?
TrophyJem - 22/3/12 at 01:05 PM

Not strictly an EFI question as I'm running carbs, but it seemed the most logical section to ask my question.

Currently my fuel tank breather is just a piece of pipe from the top of the tank that runs as high up as possible and then down below the tank in a "n" shape. The pipe is open, so when the car is parked in the garage it smells of fuel a bit. So when its parked up I just bung up the hole.

I'm thinking there must be a more elegant solution by way of a valve or something, but I can't seem to find anything.

Any suggestions?

rodgling - 22/3/12 at 01:25 PM

I think the normal approach is to put a complete loop in it - I've done this and have no problems with fuel vapours.

Slimy38 - 22/3/12 at 01:33 PM

Doesn't the breather on production cars connect back into the filler pipe just below the cap? Can the same be done here?

ernie - 22/3/12 at 01:36 PM

Burton A1 PC30 non return valve

mark chandler - 22/3/12 at 02:29 PM

Servo valve from breakers, much cheapness

coyoteboy - 22/3/12 at 02:43 PM

Yeah either a solenoid valve rated for fuel vapours (probably most to be fair) or justuse a one-way valve. One way valves have the lovely additional safety of if the car flips it won't dribble on you and ignite (however likely that may be).

thefreak - 22/3/12 at 02:43 PM

Something like this?
http://www.jjcraceandrally.com/race/fuel-unions-fittings/mocal-in-tank-breather-valve

TrophyJem - 22/3/12 at 02:54 PM

quote:
Originally posted by thefreak
Something like this?
http://www.jjcraceandrally.com/race/fuel-unions-fittings/mocal-in-tank-breather-valve


That looks like the sort of device I've been searching for.

Cheers

renetom - 22/3/12 at 05:53 PM

Hi
This is our layout (see my archive) for pict.
One way valve & a small filter, no smells & safe if you roll it.
Good luck
René

TrophyJem - 22/3/12 at 06:18 PM

quote:
Originally posted by renetom
Hi
This is our layout (see my archive) for pict.
One way valve & a small filter, no smells & safe if you roll it.
Good luck
René


Thanks. That looks a neat solution.
So do I not need to worry about expansion in the tank (like if the car is standing on a hot day)?

renetom - 22/3/12 at 06:36 PM

Hi
our layout is an air admittance so that when the tank runs down it let air in .
any expansion should vent out of the filler cap if it ever got that far ( doubtful )
René

bigfoot4616 - 22/3/12 at 08:08 PM

mine has one of these, lets pressure out as well as air in.
http://www.newton-equipment.com/inline_valves.html

or maybe not at this price
http://www.demon-tweeks.co.uk/Product.do?method=view&n=1546&p=141976&c=215&utm_source=Google&utm_medium=Base&utm_campaign=Fuel %20Tank%20Vent%20Valves

it was on the car when i got it

[Edited on 22/3/12 by bigfoot4616]

TrophyJem - 23/3/12 at 08:44 AM

quote:
Originally posted by renetom
Hi
our layout is an air admittance so that when the tank runs down it let air in .
any expansion should vent out of the filler cap if it ever got that far ( doubtful )
René


This sounds like a plan to me as the air admittance valves are fairly cheap.

Cheers

TrophyJem - 23/3/12 at 08:45 AM

quote:
Originally posted by bigfoot4616
mine has one of these, lets pressure out as well as air in.
http://www.newton-equipment.com/inline_valves.html

or maybe not at this price
http://www.demon-tweeks.co.uk/Product.do?method=view&n=1546&p=141976&c=215&utm_source=Google&utm_medium=Base&utm_campaign=Fuel %20Tank%20Vent%20Valves

it was on the car when i got it

[Edited on 22/3/12 by bigfoot4616]


Nice valve, but ouch on the price!

renetom - 23/3/12 at 09:13 AM

Yep
About £3 each, 8mm valve & filter, both on ebay.
René