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Alternate position for swirl pot

speedyxjs - 13/3/08 at 10:19 AM

Ok firstly i appologise for there being no pic. I did a drawing in paint but i cant upload any pics
In order to get a bigger fuel tank (needed for big jag engine ) could i have the swirl pot between the fuel pump and the tank, so it would go tank - pipe - swirl pot - pipe - pump - etc?

[Edited on 13-3-08 by speedyxjs]

RazMan - 13/3/08 at 11:02 AM

That's how I would do it - low pressure pump to swirl pot and high pressure pump to the injector rails.

speedyxjs - 13/3/08 at 11:29 AM

Ok, next stupid Q. Could a swirl pot be made out of a small tin?

02GF74 - 13/3/08 at 11:43 AM

how small a tin?

Is it just me who is not seeing the point of a swirl pot? My understanding that this is a cylinder with a horizontal tangential inlet coming from the injector bleed to have the fuel swirling round the side of the tank in order to prevent bubbles?

Since the fuel pump pick up is at the bottom of the tank and air being less dense than petrol, surely all the bubbles rise to the surface? The fuel picked up will only beome areated once you are down to the last few litres in the tank.

JC - 13/3/08 at 11:45 AM

Try here for diagram of system with swirl pot out of tank:

swirl pot info

How about a diesel water separator for a swirl pot? I seem to remember some discussion here before about it.

speedyxjs - 13/3/08 at 11:50 AM

^^^ Thats it

matt_claydon - 13/3/08 at 04:09 PM

quote:
Originally posted by 02GF74
Is it just me who is not seeing the point of a swirl pot? My understanding that this is a cylinder with a horizontal tangential inlet coming from the injector bleed to have the fuel swirling round the side of the tank in order to prevent bubbles?

The 'swirl' aspect is pretty much useless, but the point is that you don't want to draw air into the high pressure pump in an injection system, which easily happens when fuel sloshes around in a big tank. By having a tall thin chamber you know there will always be fuel at the outlet at the bottom.

As you point out, you don't really need the tangential inlets as bubbles are unlikely to be a problem, but they certainly don't do any harm.

britishtrident - 13/3/08 at 05:45 PM

Its the bubbles -- or rather slugs of air that are the problem.

A Seven style tank is a somewhat less than ideal shape form the fuel surge point of view.

Of course the other way round it is to weld a small collector pot onto the bottom of the tank to act as a sump.

[Edited on 13/3/08 by britishtrident]