Ally fuel tank woes. Am I just unlucky?

[TR Tim]

Hi All

 

I had my fuel system and fuel pump upgraded on the Tr5 about 14 months ago, and took the decision to replace the original tank with an ally one, not because it was corroded or anything but I was experiencing fuel starvation on tight left handers when the tank was low and was advised at the time that this was due to the absence of swirl pot or baffles in the early tanks and so decided this was a worthwhile replacement. I started to get strong petrol smells coming from the boot and after replacing all the brand new fuel pipes yet again, as it was suggested they were sweating, still the smell came and went. Finally found the first tank had split along the weld where the top left tank mount was fixed. Therefore it only leaked when the tank was nearly full. Finally found it and had the tank replaced under guarantee 2 weeks ago. (Although the first tank was fitted 14 months ago the car has been off the road for an engine rebuild for at least half of that.)

 

The second was leaking as soon as it was fitted, so a week later, last night I fitted the third tank myself. I have now lost all faith in these replacement tanks but will have to live with it for now as I sold the original tank on eBay.

Has anyone else experience similar problems, are they really that ****, or have I just been INCREDIBLY unlucky? Is it because the tank is a structural part and the ally stresses, work hardens and fails? If so why are they for sale in the first place???

Anyone got any advice or recommendation? Are there any really good options available?

 

Thanks

 

Tim

[harrytr5]

Several members in our group have suffered with alloy tanks fracturing at the mounting brackets.The tank is part of the structure of the rear.Moss does a metal tank that will serve you well.I have refitted a few with no problems up to date.

I was lucky in getting a stainless tank which are no longer available due to cost's.

So metal for me.

Regards Harry

[Motorsport Mickey]

"Several members in our group have suffered with alloy tanks fracturing at the mounting brackets.The tank is part of the structure of the rear"

 

As we've pointed out a number of times previously the structure of the TR if suffering a heavy impact from the rear or side or even in event of a rollover, can suffer from lozenging, (deforming into rhomboid what was a square).

This doesn't help the fuel tanks one little bit causing them to split or leak, bad enough when you are unrestrained, conscious and aware but downright dangerous if trapped under a upturned car and only protected from 10 gallons of fine petroleum on fire by the comedy cardboard trim panel behind the rear seat back of the cockpit.

For your safety, fitting and sealing in place an alloy rear of cockpit firewall panel behind the fibreboard panel around the rear of the cockpit will help keep the fuel out, many of the TR competitor minded TR specialist will sell you an alloy pre cut out panel for about £60 quidish, fitting it yourself will take a couple of hours.

Remember the RAC motorsport panel won't let you race without one, why be less safe in your car when driving on everyday roads ?

 

Mick Richards

Edited July 7, 2016 by Motorsport Mickey

[Alec Pringle]

Agreed Mick, firewalls are a damn good idea - as we insisted almost 40 years ago before the first TR Goodwood Sprint . . . . . .

 

Some years back an acquaintance of mine had a look at the mild steel, stainless steel and aluminium alloy tanks then on offer - with a view to manufacturing for one of our specialists. A working lifetime's experience of specialist tank fabrication, having originally served his time in that area of military aerospace. I had some lengthy explanations of the different techniques necessitated by different materials, and the cost implications thereof. Mild steel won't last for ever, but it's appropriate and cost effective for our normal purposes.

 

He regarded the then current mild steel versions as adequate and acceptable - but suggested he'd not be travelling in a vehicle equipped with the stainless or alloy alternatives then on offer, thanks a bunch.

 

In contrast, an Andy Wiltshire tank he pronounced thoroughly kosher, proper job for the purpose.

 

His quotations for tanks in aluminium alloy and stainless steel were not regarded as affordable by the specialist retailer, and he flatly refused to consider any cheaper production - unsafe at any speed, in his professional view.

 

As usual, I'm inclined to treat with respect the observations of a good professional in the particular trade.

 

Cheers

 

Alec

[North London Mike]

New tank in LNK last year, like Harry, I was aware of LOTS of problems with Alloy tanks. Stainless can also be brittle, so went for a good old steel tank from Moss. No problems

 

Moral of the story, always research the forum first, cheaper than learning from experiences

[snowric]

I fitted an alloy one last year from Revington and, after 7k, it is still fine. I used their rubber mounts, and did not 'overtighten' and also used gasoila as a liquid gasket to seal the various holes not being used.

 

smells from elsewhere (return pipe and failed MU) but tank has held up. Like Mick said, I also fitted an aluminium shield which may give some protection in a shunt.

 

there is a guy recommended{Andy Wiltshire?) who makes alloy tanks and has had very positive recommendations on here but he takes c 6-9 months to deliver as he is so highly regarded. last time i spoke to him he was constructing tanks for Ferrari Testa Rossa (the 1950s one).....

 

it's great hearing that skilled trades people like this are still in demand.

 

Snowy

[openroad]

Hi Tim, I fitted the Moss steel one on recommendation from my local tr specialist, it seems fine, although I do have a slight fuel smell in the boot only,and haven't found the cause yet,

I have also experience of the old tank, that when going round a left hand bend stuttters with fuel starvation , not a problem, fill her up !!

Cheers,

Conrad.

[stuart]

One glance at the cheaper Ally tanks will tell you why they have a problem as the mounting brackets are just flat tabs welded onto what is essentially a box. If you look at an original tank you will not that its made in two halves and the mounts are part of each side flange joint. Andy`s tanks are constructed with a proper triangulated box mounts so spreading the load after all he used to weld pressure vessels for Nuclear submarines so he should know his stuff!

Stuart.

[Andy Moltu]

My first ali tank split. The flexing of the body applies force to the tank (The tank isn't meant to be structural but does take loads when the body flexes) It was supplied with oversize holes and nylon washers to allow the body to flex without passing all the load to the tank but it still cracked eventually.

When I had my current ali tank made I had the mountings welded to a strap which was in turn loosely tacked to the tank.

Thus when the body flexes the strap flexes and not the tank. I presume the strap may crack eventually but that's easier to fix than the tank.

 

The problem with the original tanks is that the early ones are not baffled an the later ones, whilst baffled, have limited anti-urge properties so are still prone to cutting out when low on fuel. Mild steel is generally more forgiving of stress damage than ali or stainless.

Edited July 7, 2016 by andymoltu

[R J Sampson]

Revington's replaced my tank with their large capacity alloy one at the same time upgrading the whole fuel system, tank fine after 3k hard driving.

Richard Sampson

[ChrisR-4A]

I am sure as with all items there will be the odd one which fails, unfortunately we don't hear about all the ones sold which go on for years with no problems. So I would just like to add that I bought a new alloy tank for my 4A from TR Shop in 2006 and it has done over 25000 miles with no problems. Still I agree with above comments re construction and would look more closely if buying today.