Wires in the fuel tank

Questions (and answers) about Mokes that are not covered elsewhere.
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Doug G
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Wires in the fuel tank

Post by Doug G »

Given that petrol/gasoline ignites and burns somewhat rapidly, I was surprised to see the number of exposed wires and their proximity within the fuel tank and often below the fuel level (as tank is filled and consumed).

Surely the exposed wires and connections are a fire risk, sparks etc etc.

Can anyone explain why not?
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Tim
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Re: Wires in the fuel tank

Post by Tim »

Inside the tank there is nearly always a lot of petrol vapour and very little air, and the sparks are small.

At standard temperature and pressure (i.e. 'room conditions') petrol vapour is really only explosive in a fairly narrow range of ratios with air. Too much vapour or too much air and it won't ignite, and it needs a reasonable amount of heat to get it going, the tiny spark you'd get from 12v inside the fuel tank is fairly unlikely to set it off. Liquid petrol won't burn at all if a small spark occurs below the surface.

This (terrible quality) photo is the inside of the fuel sender unit out of my Mini Traveller. Its a copper coil wrapped around a phenolic former. The coil had been getting so hot at one end that the former was charred, eventually the wiring burnt out completely.
Image
I've often wondered how hot the fuel around the coil would have been getting. It definitly would have been hot enough to boil it.

Tim
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Doug G
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Re: Wires in the fuel tank

Post by Doug G »

My point exactly.
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Nigel(no top)Sykes
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Re: Wires in the fuel tank

Post by Nigel(no top)Sykes »

Let’s face it. If it was a problem then we would have been surrounded by piles of smouldering car remains long before now.
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Doug G
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Re: Wires in the fuel tank

Post by Doug G »

Nigel(no top)Sykes wrote: Tue Nov 16, 2021 18:05 Let’s face it. If it was a problem then we would have been surrounded by piles of smouldering car remains long before now.
:lol: :lol: :lol: :lol:
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Doug G
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Re: Wires in the fuel tank

Post by Doug G »

I appreciate that they can and do do it, but still wonder why it is not a fire risk or ignite the gasoline/petrol fumes etc.
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Tim
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Re: Wires in the fuel tank

Post by Tim »

I find it interesting that one of the things that the anti-ev dinosaurs constantly point to is how dangerous Lithium batteries are when they catch fire, yet they'll happily drive around with gallons of highly explosive petrol under their bums. Petrol cars catch fire in every big city every day, but no one bothers to mention it.

Tim
Any sarcastic, ignorant, libellous, unfounded or stupid opinions expressed in or through this message are the opinions of the author and do not reflect the opinions or views of any member of The Mini Moke Club or the opinions or views of any other individual.
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