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Plastic fuel lines "bundled" with electrical wires
rcx718 - 2/4/23 at 10:06 AM

I've got plastic DIN marked fuel lines. Can I run then together with electrical wires inside a plastic conduit ? The conduit is cable tied to chassis using saddle mounts.


designer - 2/4/23 at 12:19 PM

They should be separated with fuel lines below any wires.


SteveWalker - 2/4/23 at 11:36 PM

Mine run down opposite sides of the car, but I don't remember seeing any requirement for separation.


nick205 - 3/4/23 at 06:01 AM

quote:
Originally posted by SteveWalker
Mine run down opposite sides of the car, but I don't remember seeing any requirement for separation.



Mine did too in my MK Indy (SVA 2009). Don't recall any need for separation and no issues for the SVA test. Long time back and rules may have changed.


Mr Whippy - 3/4/23 at 06:39 AM

But common sense suggests it's not a good mix...


JAG - 3/4/23 at 09:24 AM

Tell that to the guys who design electric (in-tank) fuel pumps


SteveWalker - 3/4/23 at 09:59 AM

In-tank is not a risk (look at the open, wire-wound resistors that have been used as level senders. There is simply so much petrol vapour in a tank, that there is insufficient oxygen to ignite anything, no matter how many sparks you might make.


loggyboy - 3/4/23 at 10:26 AM

As mentioned, there is no requirement, but for sake of a few extra clips it makes sense.

quote:
Originally posted by SteveWalker
In-tank is not a risk (look at the open, wire-wound resistors that have been used as level senders. There is simply so much petrol vapour in a tank, that there is insufficient oxygen to ignite anything, no matter how many sparks you might make.

But petrol in a pipe is in liquid form so generally harder to ignite anyway.
https://www.youtube.com/watch?v=MS1paulCESk


coyoteboy - 5/4/23 at 11:05 AM

This is a bad idea. Almost as bad as the lack of roll-over protection in the IVA (from memory) - sure you can do it, but you shouldn't. In-tank and in enclosed environments, sure it's oxygen starved and the risk is zero (that's why you have in-tank electric pumps and contacts). But we are not talking that case here, and you're looking to not trigger a catastrophic fire due to a simple wiring fault, and let's be honest, wiring is rarely the DIY builders forte.

Keep them separate, keep fuel pipes and brake pipes inspectable, your life depends on them. Bundle your wires all you like and protect them with a fuse.

[Edited on 5/4/23 by coyoteboy]


Mr Whippy - 5/4/23 at 11:15 AM

I would also suggest using a metal one piece fuel line through the structure of the car rather than plastic or flexi hose. At either end I'd terminate on a bulkhead and then use good quality braded flexi to the engine and the tank, then there is no risk of a hidden petrol leak.


gremlin1234 - 5/4/23 at 03:14 PM

quote:
Originally posted by loggyboy
As mentioned, there is no requirement, but for sake of a few extra clips it makes sense.

quote:
Originally posted by SteveWalker
In-tank is not a risk (look at the open, wire-wound resistors that have been used as level senders. There is simply so much petrol vapour in a tank, that there is insufficient oxygen to ignite anything, no matter how many sparks you might make.

But petrol in a pipe is in liquid form so generally harder to ignite anyway.
https://www.youtube.com/watch?v=MS1paulCESk

bizarrely I have shown cars at some indoor shows (AliPally) and they insisted on near empty fuel tanks, which is the most dangerous from an explosion point of view.


Mr Whippy - 5/4/23 at 08:58 PM

quote:
Originally posted by gremlin1234
quote:
Originally posted by loggyboy
As mentioned, there is no requirement, but for sake of a few extra clips it makes sense.

quote:
Originally posted by SteveWalker
In-tank is not a risk (look at the open, wire-wound resistors that have been used as level senders. There is simply so much petrol vapour in a tank, that there is insufficient oxygen to ignite anything, no matter how many sparks you might make.

But petrol in a pipe is in liquid form so generally harder to ignite anyway.
https://www.youtube.com/watch?v=MS1paulCESk

bizarrely I have shown cars at some indoor shows (AliPally) and they insisted on near empty fuel tanks, which is the most dangerous from an explosion point of view.


I don't think its any more explosive unless the fuel was heated to its flash point (ever hear of Flight TWA800), there just isn't enough oxygen to burn. I think they are more concerned on how much fuel there is to burn if there was a car fire in an enclosed space. If there were about 50 cars with full tanks that's around 2 tons of petrol!


gremlin1234 - 6/4/23 at 08:15 PM

quote:
Originally posted by Mr Whippy
I don't think its any more explosive unless the fuel was heated to its flash point (ever hear of Flight TWA800), there just isn't enough oxygen to burn. I think they are more concerned on how much fuel there is to burn if there was a car fire in an enclosed space. If there were about 50 cars with full tanks that's around 2 tons of petrol!

buncefield exploded because that morning was so cold it was a very low vapour pressure. fuel and a lot of oxygen


scudderfish - 7/4/23 at 07:36 AM

quote:
Originally posted by gremlin1234
quote:
Originally posted by Mr Whippy
I don't think its any more explosive unless the fuel was heated to its flash point (ever hear of Flight TWA800), there just isn't enough oxygen to burn. I think they are more concerned on how much fuel there is to burn if there was a car fire in an enclosed space. If there were about 50 cars with full tanks that's around 2 tons of petrol!

buncefield exploded because that morning was so cold it was a very low vapour pressure. fuel and a lot of oxygen


That was a bloody loud bang! I live about 5 miles away and I thought the house was coming down.


rcx718 - 8/4/23 at 06:44 PM

Thank you all for the replies.

I spent ages looking through the manual for fuel line requirements but couldn't find anything. I swear there once was a section on fuel lines.