Water in Fuel Tanks

[4129R]

How do you get access to the inside to install the fitting or its nut?

Through the hole where the sender fits in. I have a very long pair of mole grips to put it in place, and stop it turning while I tighten the nut on the outside.

I think it can be done without even taking the tank out.

[dakazman]

  An S2 tank sender is on the forward side of the tank. all most impossible to access it with firewall in.
Dakazman

[EuropaTC]

I now have a blocked outlet pipe. I think I can drill out that pipe and replace it with a 6mm brass bulkhead fitting with washers either side for £5.00. A new tank is £400.

Hi Alex,
If you can do this then I'll be interested in a photo of what you've used. 

One thing I regret about the tanks I made is that I stayed with the Lotus balance pipe diameter and with 20/20 hindsight I wish I'd have fitted a larger diameter instead. Not so much for fuel delivery when running but it would have made the levels in the tanks balance much quicker when filling up. I always used to end up filling both tanks to get the max capacity because it took so long to balance through that 5-6mm pipe.

I'm not about to weld in another outlet on a tank that's had petrol in, but something like you've described could work.

Brian

[4129R]

This is on order:-

https://www.ebay.co.uk/itm/353584134924

It comes in 6mm, 8mm, and 10mm sizes.

I have also ordered this one:-

https://www.ebay.co.uk/itm/155077952945

The nuts are very small, so thin large washers may be needed with O rings or rubber washers to give a liquid seal around the hole.

If I cannot locate the fitting from the inside and hold it firmly while tightening the nuts on the outside easily, I thought of using an electrical wire, threading it through the fitting, and then putting the wire from the inside, though the hole, and sliding the fitting down the wire, into place. Then use lock nuts on the outside to hold the fitting while tightening the nut on the washer.

If I am unsuccessful, I will employ a gynaecologist !

[Kendo]

I thought there were washers, like the Seloc washers used on theTC cam cover, that incorporate rubber seals for sealing around threaded fasteners. (Or is that what you were talking about. )

[4129R]

I have never seen metal washers with rubber attached on one side, except on cam covers, and I thought the rubber was separate on those.

[EuropaTC]

Hmm, interesting gadget, I could see that working with the wire trick to get the internal nut in place. Maybe extend the area to give it more grip on the tank wall and have an external gasket to seal it up ?

Every year when I go through the "fill one tank, move over, fill the other" dance I keep thinking that I really ought to sort it out. I reckon a 1/2" balance pipe half way up would improve matters a lot and I've sketched out a few ideas on how to make it leak tight, but crazy though it sounds, nothing as simple as that !

Brian

[4129R]

Every year when I go through the "fill one tank, move over, fill the other" dance I keep thinking that I really ought to sort it out.
Brian

I quite like filling up. Normally people approach me and talk about the car. Having two fillers I think is a bragging point.

At least they are very easy to fill. Finding E5 petrol is not as easy.

[GavinT]

The nuts are very small, so thin large washers may be needed with O rings or rubber washers to give a liquid seal around the hole.

Yeah, they are a titch small. There's also a stainless version (link below) that might have slightly larger nuts and you could more confidently crank it down a bit harder.

EDIT: One of the niggles with this sort of application is it kinda requires decent tightening of the fitting and that in turn dictates something more robust than, say, nitrile O-ring / washer sealing. Maybe ally crush washers and a smear of fuel proof sealant is the go?

https://www.ebay.co.uk/itm/394241409993

There's also purpose built tank fittings, too.

https://www.ebay.co.uk/itm/274119916355

[4129R]

Thank you Gavin for that link.

I am now trying to work out the 6AN fittings I will need to connect that tank fitting to the copper pipe.

[EuropaTC]

Finding E5 petrol is not as easy.

Hmm, you're right there. Our nearest Tesco (Skegness) has just installed some pumps with their Momentum brand which used to be E5. Prior to that I had to go to the other side of Boston to get the octane rating and to be honest, when we had the Cayman unless it was convenient I'd just use regular and throw in some octane booster.   

The Lotus's never drove the same mileages and a tank lasted well over a month but even so I've changed the hoses on the Elan/Europa for modern, supposedly E10 resistant specs.  I think it does make a difference because the Elan has rubber hose inside the boot (electric pump/regulator) and if left closed for a while you could smell fumes when you opened it even though there was no visible leakage.  I assumed it was permeating the previous hose material even though that was R6 spec IIRC, it's R9 now, significantly lower permeation specs.

[Dilkris]

This is on order:-

https://www.ebay.co.uk/itm/353584134924

It comes in 6mm, 8mm, and 10mm sizes.

I have also ordered this one:-

https://www.ebay.co.uk/itm/155077952945

I would be careful using those - technically they are not designed for the application you intend - I think you will have problems sealing them against the tank as the actual area of the sealing faces are very small. I am happy to be proved wrong though.   

[Fotog]

I agree that those are not really bulkhead fittings.  I think they should look like the attached photo, but smaller.

In my case the outlet pipe was gunked up from some 30 year old fuel.  I used an incandescent lamp to warm the tank at the bottom and soften that stuff, and in a half hour was able to get a pipe cleaner through it.  Using a number of those along with acetone I cleaned it out and it's been working fine for several years.

[4129R]

I agree that those are not really bulkhead fittings.  I think they should look like the attached photo, but smaller.

In my case the outlet pipe was gunked up from some 30 year old fuel.  I used an incandescent lamp to warm the tank at the bottom and soften that stuff, and in a half hour was able to get a pipe cleaner through it.  Using a number of those along with acetone I cleaned it out and it's been working fine for several years.

Unfortunately my pipe is clogged with fibreglass resin. I Googled what dissolved the resin. Acetone. I have some chips of resin soaking in acetone now for 16 hours, they soften on the outside but as yet have not dissolved.

[Dilkris]

I have been following the later part of this thread with interest as replacing the outlet pipes from my tanks is on the never ending "to do list" - the photo shows them to be somewhat "fragile" - they have just a 4mm ID which would account for the delayed balance rate when trying to fill both tanks. (As discussed above)
My approach is as per the photo's - I simply could not find "off the shelf fittings" anywhere and as discussed above, "bulk head" fittings are not ideal - (sorry 4129R just an opinion  ) 
I am no machinist (as you can see  ) but made the following - yes I will need 2 - my plan is to remove the original 4mm feed pipes and replace with these - IF this proves impossible as the originals are situated close to the curvature of the side wall of the tanks - I'll blank the originals and relocate them.
Note: These home made fittings have a 8mm bore; "yes" - I would have preferred to machine them from brass but brass fittings in this size are expensive, coupled with the fact that the fittings I used were in the workshop.