on the tank i have bought there is a breather pipe near the sender would a length of fuel pipe on this be adequate?

Is it a breather or a return pipe? I made my tank and used a mini filler neck which uses a vented cap. I put a return into the filler neck and when the engine is running a lot of petrol goes back to the tank through it. This is on a 2.0 pinto with the standard mechanical fuel pump.

If its a breather it should have a non return valve in it. Jon Ison came up with a good tip a couple of weeks ago. ie to use a tyre valve. I had to reduce the spring rate on the one I used but works well.
Still have the pipe loop and finish pointing down but just put the valve in the end.

HTH Gordon

Gordan,

I've fitted a tyre valve also
But I haven't redused the spring rate, how do you do that?

Also, did you fit yours so air could go into the tank, or out of it?

Cheers

I am going to use two tyre valves attached to a 'Y' connector, the valves only open at about 2 psi, so one will open if there is 2psi pressure, and the other will open if there is 2psi vacuum. Attached to a fuel marked pipe, well above the tank, I think there should be no SVA problems..........unless anyone knows different?

Mine just allows air into the tank so will stop anything trying to get out, but Marks idea sounds good.
Note the valves must point down, somebody failed on that point recently.

Why have they got to point down?, I thought as long as they are well above the top of the tank they should be OK

Dangerously enough,

mine passed SVA last year with only an open petrol tube about 6 inches long from the top of my ally tank.

Realsied how bad the petrol swirl was when a bike flashed me and said i had a leak!!

In theory if i braked hard now, petrol would shoot over my helmet and shoulders with the aim of my pipe - not good, and will redesign v. soon.

Is it ACTUALLY an SVA requirement. I was looking in the manual last night and couldn't find any mention of it. (It isn't the most up-to-date version) Common sense tells you it should be vented but surely a length of hose with a return on it is sufficient.
If it does have a valve and only allows air in, what happens if its stood outside on a hot sunny day building up pressure in the fuel tank

I phone Beverly SVA test centre and they told me they didn't care what I did with it!

Seems stupid when they are bothered about seamingly trivial stuff.

Thats good enough for me

Hi All

Just thought i'd post about an inline breather i've bought from http://www.harris-performance.com/
only £10 and has a ball in it to stop leaks if you roll, safer than an open pipe

Adrian
Rescued attachment breather.jpg