scuttle fuel tanks and minimising fire risk

[JonE]

I read something in a magazine about scuttle tanks being a fire risk after topping up, and advocating using shielded modern plug caps and 'adopting a proper screw top' for everyday use...

I'd be interested to know whether the bayonet fixings can be improved, need replacement washers that may be missing etc... and indeed do people adopt any other tactics other than just being generally careful?

[Chris KC]

Hi Jon,

I've certainly heard of a few cars succumbing to fires over the years. My 'gut feeling' is you want to worry more about electrics than fuel tanks - petrol is not quite as flammable as people imagine, though that's little consolation once a fire has actually started. But then it won't matter a hoot where it's located in the car. I generally try not to fill the tank so high that it spills out while driving, otherwise rarely give it another thought.

I did once allow a battery lead to finally wear through its insulation on a sharp edge - the resulting shower of sparks just under the dripping fuel tap was quite impressive (but still didn't cause a fire). On the other hand I once found a whole load of melted insulation, where too small wire sizes had been used for lights.  

I would urge owners of Ulster-rep type cars to pay an occasional thought to the underside of their fuel tanks - grit and water can collect between tank and scuttle and cause rust spots which may penetrate the tank. I caught mine while there was still some metal left, now I seat it on broad EPDM rubber strips with gaps to allow drainage.

I'm not saying it can't happen, but it sounds to me like the kind of scaremongering that magazines tend to resort to from time to time to fill their pages.

[Tony Press]

I read something in a magazine about scuttle tanks being a fire risk after topping up, and advocating using shielded modern plug caps and 'adopting a proper screw top' for everyday use...

I'd be interested to know whether the bayonet fixings can be improved, need replacement washers that may be missing etc... and indeed do people adopt any other tactics other than just being generally careful?

New bayonet fuel caps are available from cherished suppliers and providing the pins in the filler neck aren't too  worn usually the tank is well sealed.

(The tank caps usually seem to be black so a paint job is required) .

Treated carefully when filling, a scuttle tank should be OK - the occasional spill doesn't seem to be a problem, neat fuel is quite difficult to ignite.

Cheers, Tony.

[Hedd Jones]

Funnily enough I thought about this the other day. The RAC man tried telling me off for spraying WD40 on my own car saying it was a fire risk. I dont think he was at all impressed by my attitude. Perhaps if he'd have taken 20minuites rather than the 3 hours to turn out I may have been a little more worried about the volatiles. Come off it. A quick spray 2 hours earlier. And he wont do a spart test? Really?

I suspect he would have a coronary if he saw me tickle the carb and get fuel all over the exhaust on my short wheelbase saloon before starting it on a morning.

[Erich]

Many years ago,I used to race an Aermacchi 350, a flat single. One day, the Del Orto carb decided to leak all over the cylinder and exhaust. At first I thought it was steam(it was wet out) then realized, "THAT ISN"T STEAM!" No flame and we all survived.

I do enjoy the old photos of various cars, including Sevens, in the pits with the drivers and mechanics working on the cars while smoking, including fueling up.

Erich

[merlinart]

Many years ago,I used to race an Aermacchi 350, a flat single. One day, the Del Orto carb decided to leak all over the cylinder and exhaust. At first I thought it was steam(it was wet out) then realized, "THAT ISN"T STEAM!" No flame and we all survived.

I do enjoy the old photos of various cars, including Sevens, in the pits with the drivers and mechanics working on the cars while smoking, including fueling up.

Erich

Interesting post this.

I build three wheeled cars with scuttle tanks and one has to be careful when filling, common sense of course. A good vented filler cap and I use an Enots Aston copy flip top filler cap. I have a scuttle tank for my Ulster rep with a simple screw cap, and I might review the cap, not sure yet.

Yes beware, and lots of common sense.

One must remember pilots of Hawker Hurricanes in particular, and during the Battle of Britain, but also in any area of combat, the fuel tank was just above the pilot's knees, and parts of the cockpit were simply plywood and doped fabric. Now that was a fire risk, and many pilots became the "Guinea Pigs" who required plastic surgery at the Queen Victoria Hospital, East Grinstead under Archibold McIndoe.

I suspect we all have suitable stories to tell....40 odd years ago, I was fiddling with my mother's Fiat 126 and ended up with a petrol pipe off and went to turn the engine by pushing a broomstick against the starter lever, whilst the distributor cap was off, a spark and whoosh, the engine bay was aflame. I learnt a lot from that!

Lots of old cars of course have scuttle tanks, I've been looking at MG M Types in the last year and they have them.

Arthur

[Nick Turley]

I read something in a magazine about scuttle tanks being a fire risk after topping up, and advocating using shielded modern plug caps and 'adopting a proper screw top' for everyday use...

I'd be interested to know whether the bayonet fixings can be improved, need replacement washers that may be missing etc... and indeed do people adopt any other tactics other than just being generally careful?

On thing I am an advocate of for scuttle tank cars is have the original fuel filter in place. It helps break the motion wave up on the petrol surface thereby keeping a lot of pressure of the cap seal.

[JonE]

Nick - is that a gauze thing which protrudes down into the tank from the filler? (like the modern things in windscreen washer top ups)
Are they available from any suppliers?

[AustinWood]

As mentioned before in this thread petrol vapour is only really dangerous if there is a spark to ignite it. It just evaporates and disperses.
For this reason it is not advisable to add fuel with the engine running. Also best not to fill to the brim to avoid fuel slopping under braking.

[Steve Bryant]

If someone knows the dimensions of the gauze filter cone for the filler neck  I'm sure that those of us who can make such things would be very grateful  for the information.
Stephen