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Re: Securing fuel tank breather pipe to roof.

PostPosted: Fri Jan 26, 2018 1:24 pm
by gus
Again, no reason to go across the roof, it works fine just over the c pillar vent, and everything remains easy to access if any maintenance is required

A side question, when adding the vent line to the filler neck, does it radically improve the filling efficiency?

I guess I have got used to pulling the nozzle out, holding back the vapor recovery snorkle and finishing the fill.

Re: Securing fuel tank breather pipe to roof.

PostPosted: Sat Jan 27, 2018 11:03 am
by TeeJay
Some of the Key points of the ?Club Lotus? modified breather.

When tank is filled, air is expelled at a high rate via the big bore tubing connected to the filler neck.

The reason for the breather tube still going to roof height is to help eliminate fuel discharge via the tubes. Much lower tubing can still spill out fuel, particularly when travelling around fast sharp corners with a full tank of fuel.

Re: Securing fuel tank breather pipe to roof.

PostPosted: Sat Jan 27, 2018 11:11 am
by alan.barker
+1 the breather tube still needs to go up and over the top :wink:
Alan

Re: Securing fuel tank breather pipe to roof.

PostPosted: Sat Jan 27, 2018 1:11 pm
by gus
Baloney


It never happens

and shall we wonder how the convertible conversions fare?

the angle at which the car would have to tip in order to spill fuel would mean it is on its side

Re: Securing fuel tank breather pipe to roof.

PostPosted: Sun Jan 28, 2018 1:51 am
by Bigbaldybloke
Tee Jay
How have you secured the tapping point into the fuel filler neck please, how have you sealed around it, do you have something securing it attached inside the filler neck?

I?m thinking I?ll need some sort of screwed boss brazed inside the filler neck.

Cheers
Simon

Re: Securing fuel tank breather pipe to roof.

PostPosted: Sun Jan 28, 2018 12:31 pm
by TeeJay
Simon, you?ve got it in one.

Yes a tapped boss shaped and brazed to the inside.
My picture shows the initial setup, which I had tapped the filler neck.
It is import to position the filler neck so that the fuel cap is in the correct position and then position the hose connector. The boss was then brazed to the filler neck.

For further information, the photo shows the yellow (earth wire), which I used to route and measure the tubing which goes over the roof and out into the RH rear wheel arch. All being part of the revised breather system.

fuel-filler-vent.jpg and
breather-hose-route.jpg and

As I fitted a new roof lining, it was an easy decision to route the hose in the roof as recommend.
I had spent many months scraping the paint off the body, then used fibre glass matt to reinforce the know weak areas of the body, then tissue for repairs. Then a long protracted spraying of the several layers of paint. There was no way I would risk a breather system which could result in petrol spills.

Re: Securing fuel tank breather pipe to roof.

PostPosted: Mon Jan 29, 2018 5:40 pm
by Bigbaldybloke
Thanks for those pictures, most helpful. Plan decided, just need to obtain the necessary fittings and get on with it.

Re: Securing fuel tank breather pipe to roof.

PostPosted: Tue Jan 30, 2018 4:47 pm
by DavidLB
I have a system as tea jays been done about three years or so and works fine no smell and with the mx5 bit no overflow from the filler cap

Re: Securing fuel tank breather pipe to roof.

PostPosted: Thu Oct 03, 2019 6:53 pm
by Donels
BBB this is how I did my filler neck mod using standard but modified plumbing fittings and sealant. The breathers needs to be removable to fit the filler neck through the body.

df7ba2fb-51aa-430d-aacf-08f79ffd12b4.jpeg and


873f0f41-c6f7-40e2-a9f7-b73e9d3b15fb.jpeg and

Re: Securing fuel tank breather pipe to roof.

PostPosted: Thu Oct 03, 2019 8:26 pm
by Bigbaldybloke
Hi all, I used all the info everyone provided and came to a similar solution using slightly different parts but to the same effect. It?s actually two parts machined and brazed together to form the boss that was then brazed into the filler neck and the third part screwed into that once the filler neck was in the car. I haven?t fitted the breather pipes over the roof, I?ve gone for breather valves and a pipe that goes up the rear pillar and then back down into the same side wheel arch. I?ve posted pictures in another thread but can repost here if anyone is interested.