Alez
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| posted on 19/5/05 at 07:27 AM |
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Fuel tank concerns
Hi!
I've been told about some fuel tank made out of plastic, rubber or something. Apparently these are used in competition to prevent fire in the
event of an accident. Do you know these?
The thing is I'm using the Locost on the highway, where you sometimes find the preceding cars stopped suddenly. I have good brakes and I think
the Locost chassis is quite good for crashing generally but I'm concerned about the car behind.
Another solution I've heard is the relocation of the tank to the front (it's a BEC so there's room for it), but putting it near the
engine looks even more dangerous to me plus it's not good for weight distribution. How about moving the fuel tank forward (can't figure
out where to attach it to just now), so it sits roughly on the top of the rear axle? Although that would move the danger closer to the driver. What do
you think?
Cheers,
Alex
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Staple balls
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| posted on 19/5/05 at 07:57 AM |
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personally, my concerns from cars behind is mostly the ford pinto situation* especially if you only have a GRP arse end, but i figure that's
pretty avoidable with a top loop and the uprights between
a fuel cell (the race style things) could work, but unfortunately, they're quite expensive and afaik not available in a locost shape,
i've heard custom ones are available, but i'd expect silly money. a square fuel cell could be mounted on a shelf above the rear axle
pretty easily, but you'd lose any possible boot space.
* http://www.fordpinto.com/blowup.htm
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ned
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| posted on 19/5/05 at 09:37 AM |
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i don't think it's worth worrying about alex, the number of cars there are out on the road how many have we heard about that have had a
rear end shunt and the fuel spilt everywhere or worse caught fire. I have seen one picture of a RACE where a fuel tank split, due to collision, but
this is hardly the sae circumstances as road use.
If you're really paranoid I suggest you fit a plumbed in fire extinguisher with a big red button on the dash and a bag tank. These are what we
run on a racecar, but i persopnally don't think them at all necessary for road use.
Ned.
beware, I've got yellow skin
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britishtrident
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| posted on 19/5/05 at 10:41 AM |
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The old trick with steel tanks was to add a couple of layers of GRP to the outside to reduce the likelyhood of the tank splitting. This used to be
recommended in thr RAC MSA Blue Book.
Petrol fires are common than they were mainly I suspect because modern fuels ignite more easily in an accident situation. The main thing is to route
the electrics as far from the tank as possible.
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Bob C
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| posted on 19/5/05 at 05:33 PM |
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I'm also concerned about this & am seriously considering a mild steel tank rather than Ally simply because I feel it would be less likely to
split in a shunt. But is this actually true? has anyone anywhere tested for the best material for tanks? How would a TIG welded stainless tank hold up
in a smash? If the old heads could throw their collective wisdom & experience into the debate I'd be very interested.
Cheers
Bob C
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ned
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| posted on 19/5/05 at 09:29 PM |
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i would be interested to know the outcome of any theory/tests relating to how materials used to make tanks would deform/split in a shunt scenario, but
think it's worth bearing in mind that it is equally if not more likely that the tank mounts/straps and or filler/outlet pipes may become
dislodged before the tank itself splits open...
Ned.
beware, I've got yellow skin
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Bob C
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| posted on 19/5/05 at 11:14 PM |
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Fair enough Ned, but in a live axle locost the tank has somewhere to go - in an IRS setup like mine it will be squashed between the back panel and the
framework holding w/bone brackets and diff...
cheers
Bob
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Jonr
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| posted on 19/5/05 at 11:26 PM |
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Plastic tank!
They just bend, with no tears or bursts. Had a mate with a Jeep Wrangler, it had a plastic tank with some horrendous dents in it, but never any
problems.
Your standard petrol can is now plastic, throw that around, jump on it, drive over it! It'll survive better than any equivalent metal one.
No empirical evidence or tests for it, just gut feeling that a plastic tank is going to be much more resillient! (make sure the thing is earthed
though)
Think car builders solutions do a nice plastic one.
all just IMHO
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Alez
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| posted on 20/5/05 at 07:27 AM |
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Thank you for your thoughts, guys. What do you think about just relocating the original aly tank to the top of the rear axle, mounted on some shelf,
or with brackets or something? Closer to the driver which is worse, but farther from the collision point, which is good. Also farther to the electrics
hot spots, ie rear lights (I'm not too concerned about wiring which is not exposed and not likely to have it's isolation damaged during a
collision). I'm not sure wether this is a better or worse situation than the original.
Thanks for the pointer Jonr, found it here:
http://www.nfauto.co.uk/fuel_tanks.htm
Cheers,
Alex
[Edited on 20/5/05 by Alez]
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ned
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| posted on 20/5/05 at 08:19 AM |
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Alex I know of one, possibly two 7-type cars (both members on here if memory serves correctly) where the tank is mounted above the axle as previously
suggested.
Ned.
beware, I've got yellow skin
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andyharding
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| posted on 20/5/05 at 11:20 AM |
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Petrol really isn't as dangerous as people think. You can tip petrol on your exhaust manifold and it wouldn't ignite. It actually needs a
flame or a hot spark. This came from a fire chief.
The only way I can see you catching fire is if you bust the tank and then hit an barrier/wall or something which makes a load of sparks.
If you get shunted up the rear hard enough to burst your tank and create enough sparks to ignite it the fire will be the least of your worries.
I'm going with a 1.2mm ally tank mounted as far back as possible. I'm more worried about getting T-boned.
Are you a Mac user or a retard?
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Bart Vangampelaere
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| posted on 23/5/05 at 11:00 AM |
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quote:
Originally posted by andyharding
Petrol really isn't as dangerous as people think. You can tip petrol on your exhaust manifold and it wouldn't ignite. It actually needs a
flame or a hot spark. This came from a fire chief.
The only way I can see you catching fire is if you bust the tank and then hit an barrier/wall or something which makes a load of sparks.
I don't really agree here... Diesel will NOT ignite if you throw a match in the tank, but petrol is altogther a different matter. It can ignite
a lot faster if it's allowed to produce fumes. The gasses will catch fire a lot easier then the liquid. As a matter of fact I just read a nice
story about a burned out engine room of a Renault Alpine GT V6. No sparks, just a leaking fuel line and heat.
If the tank would split and fuel go on the hot brake discs it WILL burn.
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Volvorsport
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| posted on 23/5/05 at 11:28 AM |
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wasnt NF auto developments offering plastic fuel tanks for locost type cars ?
www.dbsmotorsport.co.uk
getting dirty under a bus
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craig1410
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| posted on 23/5/05 at 12:09 PM |
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Brake fluid is much more likely to ignite than petrol in my experience. I once had a fuel pipe develop a nasty split and spray fuel onto a red hot
turbocharger on my Metro Turbo. There were copious quantities of thick white smoke but no flames.
Cheers,
Craig.
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britishtrident
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| posted on 23/5/05 at 03:53 PM |
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Brake fluid and petrol ignite quite differently but both burn pretty well ;-()
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britishtrident
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| posted on 23/5/05 at 04:05 PM |
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quote:
Originally posted by Bart Vangampelaere
quote:
Originally posted by andyharding
Petrol really isn't as dangerous as people think. You can tip petrol on your exhaust manifold and it wouldn't ignite. It actually needs a
flame or a hot spark. This came from a fire chief.
The only way I can see you catching fire is if you bust the tank and then hit an barrier/wall or something which makes a load of sparks.
I don't really agree here... Diesel will NOT ignite if you throw a match in the tank, but petrol is altogther a different matter. It can ignite
a lot faster if it's allowed to produce fumes. The gasses will catch fire a lot easier then the liquid. As a matter of fact I just read a nice
story about a burned out engine room of a Renault Alpine GT V6. No sparks, just a leaking fuel line and heat.
If the tank would split and fuel go on the hot brake discs it WILL burn.
Inside desel and kersene tanks the vapour concentraion is usually well below the combustable limmit. in petrol tanks the vapour concentration is so
high it won't burn.
Leaking fuel is a different matter a petrol spill wil form carpet of flamable vapour many times the the area of the spill.
One of the most dangerous leak is a fine spray any type of fuel or oil spray will ignite easily and produce a very hot fire.
[Edited on 23/5/05 by britishtrident]
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