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Alloy Fuel Tank

PostPosted: Fri Feb 10, 2006 10:43 pm
by Hamish Coutts
This one is aimed at Keith.


In your experience - I'm fitting a new ally petrol tank to my +2. There are the usual connections for the fuel guage and the fuel 'low' light.

I remember you warned people who had fitted an alloy radiator to make sure the rad was eathed properly to avoid problems(?). Are there any similar precautions that should be taking when fitting an alloy fuel tank? (or indeed any other things I should watch out for?)

The supplier didn't advise anything.

Advice appreciated.

Hamish. :?

PS can you send me your e-mail address please. I have a couple of interesting sound tracks I picked up in France recently of the Matra V12 being well used round Le Mans. You may well be interested.
Kinda makes the hair curl on the back of your neck when you listen to them. Sorts out the men from the boys!! :D :D

Re: Alloy Fuel Tank

PostPosted: Fri Feb 10, 2006 11:26 pm
by type26owner
I had a really close call with the steel fuel tank couple of years ago. The wiring harness going to the tailights chafed through and shorted to the filler neck on the tank. The tank just happened to be full of fuel when this happened and it saved my life. The path it took to earth was through the fuel level gauge. The insulation on the black ground and the level circuit wires were charred. But more importantly the fine wire wound on the rheostat inside the gauge had vaporized just like a flashbulb went off. Because the fuel gauge was totally immersed in fuel it did not detonate. Whew!

You might add another earth wire but I doubt you can stop that ni-chrome ~.001" diameter wire in the original sender from igniting a combustible mixture. I hooked it back up anyways! Hell, I drive a Lotus in the flood of SUVs so it just proves I've got very little common sense afterall. :lol:

I secured the wiring harness well away from the tank with plastic clamps. Ahh, that was my second episode smoking a harness. A fuse would not have prevented it unfortunately. :cry:

A fuel bladder cell is still on my to-do list. The fuel cell uses a capacitance type level sender which I think is a safer way to go. :wink:

Re: Alloy Fuel Tank

PostPosted: Sun Feb 12, 2006 9:29 pm
by chrishewett
Where did you get your ally fuel tank? I don't need one right now but a future project!
I would love to hear the matra, you have my email address.

Re: Alloy Fuel Tank

PostPosted: Mon Feb 13, 2006 5:31 am
by reb53
Re interesting soundtracks, if you like F1 engines playing tunes try the Renault F1 site for a V10 playing "We are the Champions".
All in one take .
Here's the link: ... cm:3-41673


Re: Alloy Fuel Tank

PostPosted: Mon Feb 13, 2006 9:13 pm
by Hamish Coutts
Hi Chris,

No choice but to go for a new tank. There was one other option (Northern Radiators who do a ceramic coating both inside and outside the old tank) but I didn't really fancy going that way. I would still have the old tank and as for the coating??
The inside of the old tank was coated with rust and the bottom looked like a sandy beach with rust particles. Eh, not ideal for uninterupted motoring!

Paul Matty got one made for me (Roy is very helpful). Their price (the wrong side of ?350) was competitive compared to the fabricators I contacted. Tank looks good and guess what - it fits! :D :D
mattys picked up my old tank to use as a pattern - good riddance to it.

Couple of teething problems:
1. The fuel outlet was tapped for a ?" BSF banjo bolt. The original was ?" BSP and of course, wouldn't fit. Mattys sent me a new one.
2. This is still unresolved. Mattys said the fuel gauge and warning light would both work - they don't. The tank is half full (I'm an optimist!) but the gauge shows just a smidge over empty. The wiring and warning lamp test OK but the warning lamp wouldn't light when the tank was empty. Annoying :x

I'm waiting on Mattys getting back to me, Roy is suitably apologetic.



PS can you send me your e-mail address again - the hard drive on my laptop went AWOL and with it went nearly all of my e-mail addresses. For the life of me I can't get the backup to restore properly. :cry:
I'll send you the Matra stuff when I get it. They are MP3 files. Can't stop playing them. :D :D How I wish I was driving that car!

Re: Alloy Fuel Tank

PostPosted: Mon Feb 13, 2006 9:15 pm
by Hamish Coutts

I'm having a senior evening - my email address is [email protected].


Re: Alloy Fuel Tank

PostPosted: Mon Feb 13, 2006 10:22 pm
by sparkey
Hi Hamish,

I've been having some trouble with my fuel gauge and warning light sender which needed some repair ( it's in a standard tank). I found that the send is extremely sensitive to the angle of the arm that holds the float, and that this arm (basically a piece of wire) is easily bent. If it's bent even a couple of degrees from where it should be then you will find that the reading is wrong.

Alternatively as the sender works on resistance could it be that the resistance of your alloy tank to earth is effecting the reading. I have soldered an earth connection dirctly onto the circular "body" of the sender - the bit that fills the hole in the tank - and connected that directly to the battery below which has made mine more reliable.


Re: Alloy Fuel Tank

PostPosted: Tue Feb 14, 2006 9:57 pm
by Hamish Coutts
An up date on my new alloy fuel tank. Thanks a lot for the replys. Only shows the generosity of the members - so many replies. Keep it going guys.

The very helpful Roy from Mattys has called to ask me to test the fuel sender. Have done so and the upshot is that his tank manufacturers have fitted the wrong fuel sender to the new tank. When it was connected as recommended, the gauge worked perfectly! The only thing is that the red 'fuel low' warning lamp doesn't work. Looks like the manufacturers will have to send me a new fuel gauge transmitter that also works the 'low fuel' lamp.
That's 2 careless mistakes. (the first one being the wrong thread for the bamjo bolt on the fuel outlet)
Being a Lean process engineer it's all a bit annoying. These are really basic mistakes that could be prevented by some simple checks.
Not the fault of Mattys. Perhaps the next time people will have learned and the mistakes don't happen. That's the theory at least.

The new tank is fab, looks really well made, doesn't leak or rust and fits! (how many things have you got new for your beloved car that don't fit? Straight off I can think of handbrake cable (far too long), throttle cable (wrong thread on the adjuster, too long and very poor quality [high friction and jerky] - in effect unuseable), engine mounts that fell apart very quickly and damned wiper blades that only last a few weeks before the backing parts company from the so called wiperblade.
Looks like I'm doing OK with the tank so far.

Rant over,

Hamish. :roll:

Re: Alloy Fuel Tank

PostPosted: Wed Feb 15, 2006 5:03 pm
by pereirac
I asked one of the UK Elan specialists about alloy tanks a couple of years ago when my Elan was in bits and was told that they had stopped selling them as they were too brittle and split ....? Was this just an excuse?

Re: Alloy Fuel Tank

PostPosted: Wed Feb 15, 2006 5:43 pm
by M100
pereirac wrote:I asked one of the UK Elan specialists about alloy tanks a couple of years ago when my Elan was in bits and was told that they had stopped selling them as they were too brittle and split ....? Was this just an excuse?

Probably, there are tanks in Caterhams to my knowledge that are 20 years old with no problems.
In the Elan I'd be worried about the possibility of water/condensation being trapped between the tank and the boot floor leading to corrosion similar to that seen on the Elise floorpan. If the tank can be properly spaced from the boot floor to allow air to circulate its less of a worry but if not then a coat of etch primer or alodine and an epoxy based paint on the bottom of the tank would be a good idea. Definitely don't sit it on thin rubber mats!