Fuel Return To Tank

[brumster]

I guess there's nothing technically bad about it - flow isn't going to be a problem, and safety-wise I can't really see a problem because the pump is never going to be running when you've got the filler cap off. I would just ensure the flow into the filler neck is as near the bottom as you can get it and, if possible, pointing downwards...

[Guest alfaGTA]

This is the kinda thing i had in mind for the fuel return to filler neck,

 

http://www.summitracing.com/parts/MOR-65385/?rtype=10

 

Down pipe would be a must and to minimise vapours i'd vent it to near the bottom of the tank. Ideally i'd vent it into the sump in the fuel tank but that'd be showing off..........

[agent_zed]

that looks the job. is there really that big a problem with vapours? the fuel tank is full of fuel sloshing back and forth as you corner, brake and accelerate, surely the tank 'air' is already saturated isn't it? Just asking as if it is an issue i'll take my sender off and have a check of mine.

 

That piece of kit looks good and for the length of a piece of fuel pipe to drop it to the bottom of the tank it can only go to minimise fuel movement and improve piece of mind.

 

I did wonder about that sponge they put in rally cars that stops fuel going everywhere but i am not sure how worth while it is and i've put 2 baffles in my fuel tank so i'd only be able to get it in the first and last sections through sender and filler. anyone done this/have any comments?

[fry61]

Isn't the vapour/air ratio too high ( in the tank) for it to be a problem? We do after all submerge electrical gubbins like fuel senders & commutators of pumps in the stuff.

[Guest alfaGTA]

Petrol vapour is much more explosive than liquid petrol, plus add to the fact that the returned petrol will be heated by the high pressure pump, by a hot injection rail and by a hot engine bay will not help the risk of explosion in a potential crash situation. I'm trying to minimise the risk and to make sure the job is done right first time whilst i'm doing the upgrade to injection.

 

The foam/sponge in fuel tanks serves two purposes, firstly minimises fuel surge and secondly it traps fuel vapours thus lowering the risk of explosion