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wiring inside the petrol tank?


Chris Abel
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I’ve got an Alloy fuel tank being made and im planning on using the original internal fuel pump to save a few ££, My new fuel tank is deeper than the original tank and the original pump needs to be extended by 150-200mm its easy enough to extend the fuel pipe using a bit of flexible pipe and some jubilee clips and extend the support bracket but ive got to extend the wires.

Will normal automotive wire and connector blocks dissolve :huh: in a petrol tank?

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Rather than extending the pump, why not extend the intake?

I thought about that but the intake on the pump does not look like it can easily be extended. I know the standard wires on the pump are fine in petrol but if i extend the wires will normal electrical connectors and wire will they be ok or do i need special fuel resistant stuff?

if it does melt and I get some sparks in the tank, it will EXPLODE LIKE A BOMB!!!

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I thought about that but the intake on the pump does not look like it can easily be extended. I know the standard wires on the pump are fine in petrol but if i extend the wires will normal electrical connectors and wire will they be ok or do i need special fuel resistant stuff?

if it does melt and I get some sparks in the tank, it will EXPLODE LIKE A BOMB!!!

Get an internal pump from a carb V8.

The tube is far long as are the wires, plate with 6x holes same ID OD Fittings

Unbolt top half bolt up to bottom half job done

Nige

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if it does melt and I get some sparks in the tank, it will EXPLODE LIKE A BOMB!!!

I read that in WW2 some MTB's used petrol and others used diesel (maybe ours and the yanks, but not sure) and it was found (contrary to expectations) that when hit through-and-through with tracer, the diesel was more likely to explode. The explanation for this (apparently) is that the space above petrol in a tank is way-too-rich vapour and will not explode since you need a stoichiometric mix for that. The diesel, being much harder to vapourise (there is a term for this but I forgot it) actually has a more perfect mix of air and fuel vapour in the space above the liquid.

Wouldn't want to test it though!

Rog

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No, :huh:

Use the TOP half from a carb pump (very long) with the BASE of a HP EFI Pump the 2x together are hugely longer than either of the 2x as std

Nige :)

I see ill have a look on Ebay and see what i can find, if its not long enough ill just put some wires and conector blocks in a jar of petrol for a few weeks and see what happens!

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Here's what i did fitting a RR HP pump in a single hole 90 tank, for added fun i wanted the pump and fuel level sensor on the same assembly.

Fraid i don't have any pics of assembly

Removed tank & flush out several times using degreaser & pressure washer till no smell of petrol left and dried.

Took the grinder to the top and made the hole much bigger (so the sender arm & EFI pump could fit through)

Made an aluminium adaptor plate covering the big hole with a smaller hole in the middle for the pump

Nitride rubber as gasket between the tank & plate and plate and pump, ring of bolts holding it together.

Extended the bar the pump hangs off (made up a extension bar (3 or 4 inches) which bolts in place). the wires were just long enough.

Extended the rubber pipe (used fuel pipe) jubilee clips holding it

Made a bracket off the side of the bar to hang the sender unit off (took some faffing about to get it in right location and correct movement)

Pressed the old plastic terminals (fuel level & low fuel warning) out of the old top and drilled and glued them into the new one.

Made sure the pump was close to bottom of tank as possible and pump feed was well within the baffle plates

Good thing about the larger hole is it gives good access into the tank (handy if anything is anything is accidentally dropped in)

Was a bit paranoid about testing it for first time, didn't want to stand next to it and connect the pump to 12V :unsure: so... I put tank about 30 metres away down the garden, output pipe going back into tank and with a long bit of wire connected it up to 12V source while hiding safely in the garage.. no big boom so was good to go :D

If cutting and joining the wires, i would consider solder and heatshrinking them then individually run each wire separately inside fuel pipe to ensure they couldn't short even if the heatshrink melted away. not sure if wire ends into connector blocks could fatigue over time with movement / sloshing of petrol?

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I read that in WW2 some MTB's used petrol and others used diesel (maybe ours and the yanks, but not sure) and it was found (contrary to expectations) that when hit through-and-through with tracer, the diesel was more likely to explode.

ISTR in Bravo Two Zero they mention their training where they shoot petrol tanks and the comment was that it's really quite hard to make one even catch fire, and that they don't explode like in the movies.

I successfully soldered a return pipe back onto dad's RR tank but that was one that had been stood empty for ages, didn't smell of petrol at all so I gave it a go and I'm still here :)

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ISTR in Bravo Two Zero they mention their training where they shoot petrol tanks and the comment was that it's really quite hard to make one even catch fire, and that they don't explode like in the movies.

I successfully soldered a return pipe back onto dad's RR tank but that was one that had been stood empty for ages, didn't smell of petrol at all so I gave it a go and I'm still here :)

Exploding jerry cans full or half full of petrol when shot with a firearm is a load of rubbish. Me and my mates tried to blow up a petrol filled jerry can with a 9mm Browning Hi-Power out in the desert one night and all we succeded in doing was ruining a pefectly good steel jerry by putting holes in it.

To blow up a fuel container you need a very good ratio of atomised fuel air mixture and a strong spark. Any one watch Mythbusters?

Back to the plot though. The connector blocks are PVC or nylon....will not disolve or melt in petrol. Just be certain that the screws/wires cannot come undone though! Most automotive cable used these days is PVC coated and will alright.

The connections have to be rock solid though.....this is where you can cause heat build up or fires etc.

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I’ve got an Alloy fuel tank being made and im planning on using the original internal fuel pump to save a few ££, My new fuel tank is deeper than the original tank and the original pump needs to be extended by 150-200mm its easy enough to extend the fuel pipe using a bit of flexible pipe and some jubilee clips and extend the support bracket but ive got to extend the wires.

Will normal automotive wire and connector blocks dissolve :huh: in a petrol tank?

230237227.jpg

I used exacly the same pump you have in the pic when I fitted a 3.5 efi to my 90 about 10yrs ago I had the same problem.

cut off the pump cut the fuel pick up to the correct length and small rubber hose and extended the wires using halford plasic coated conectors and a old bit of wire I had on the garge floor.

I put heat shrink over both sets of conectors and never ever thought about it ever again.

I still have the tank with the pump in it from the 90.

your all making a mind numingly simple job very complex.

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I used exacly the same pump you have in the pic when I fitted a 3.5 efi to my 90 about 10yrs ago I had the same problem.

cut off the pump cut the fuel pick up to the correct length and small rubber hose and extended the wires using halford plasic coated conectors and a old bit of wire I had on the garge floor.

I put heat shrink over both sets of conectors and never ever thought about it ever again.

I still have the tank with the pump in it from the 90.

your all making a mind numingly simple job very complex.

Thanks for the help, I just wanted to make sure it would be ok, i think solder and heat shrink is the best option.

Its always better to be safe than sorry!!

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