Swirl Pot Advice

[Mitch]

Hi Dave, yes the bottom of the tank has a swirl pot, and the tanks is baffled,,, obviously not enough for the flow, But to get the tank out would need the rear panel removing (and the arches) and chances of it coming off without kinking would be slim, so I think you need a extra swirl pot and LP pump, don't see why the pump for the carbs wouldn't work, as it does switch when pressure reached, good luck and the car looks well, and next time your passing that polishing stuffs here, I forgot on sat, and im still eating choc dougnuts lol

 

Mitch

[Guest david_l_perry]

Cheers Mitch ! will pop round again soon. Ta

[Longboarder]

This is my plumbing. Works well. Reliable pumps and filters are key.

 

Nigel

[Guest Ian Maycock]

Ok time for a daft question. If a low pressure pump feeds the swirl pot and a high pressure pump feed the engine. Will the LPP be able to keep up with the HPP I.e. Will the HPP not empty the swirl pot quicker than the LPP can fill it? That is unless the volume of the two pumps are the same. Is this right?

[theduck]

pressure and flow rate are not one and the same

 

Plus, high pressure fuel returns to the swirlpot.

Edited September 21, 2015 by theduck

[Longboarder]

The HP pump takes fuel from the swirl-pot, feeds it to the injectors where some is injected into the engine but the remainder is returned to the swirl-pot. All the LP pump has to do is replace what is used by the injectors. And they don't use much even flat out which they seldom are for more than a few seconds. The LP pump also does the primary fill of the swirlpot and its continuous pumping also blows air out of the top of the pot back to the tank effectively bleeding it.

 

So any pump which can pass three gallons an hour will do. The cheapest facet does 25 US gal per hour so over-spec by about 8 times!

 

Nigel

 

Very different situation if you decide to return fuel from the rail to the tank rather than the swirl-pot. Then you do need a belter of a LP pump.

There is also good reasoning in the placement of the pipes in the swirl-pot. Feed fresh cool fuel to the middle. Take from the bottom. Warm fuel return close to the top and bleed the very top. Not perfect but some warm fuel will be bled from the top of the pot back to the tank. Cold fuel will tend to be dragged down to the HP feed. The pot will stay cooler. The bigger the LP pump the greater this effect.

Edited September 21, 2015 by Longboarder

[Guest david_l_perry]

I am going to look at locating the swirl pot at the back, either in the boot, or ideally next to the tank under the boot as I am sure I have space in that area and would rather keep the boot space free

 

If I mount the swirl pot next to the tank along side the pumps / filters etc, their will clearly be situations when the tank is full that the head of fuel is above the top of the swirl pot.

The fuel return line will still be going above this head of fuel as it returns into the top of the tank - I assume this is normal and wont be an issue, or is it best to have the swirl pot elevated above the tank for any reason....

[Longboarder]

Swirl-pot can be below, beside or above the tank. LP pump has a lift height which is the max it can be positioned above the base of the fuel tank but that's irrelevant if you put it beside the tank. The LP pump will bleed the swirl-pot perfectly OK even if the pots below the tank.

 

Nigel

[Guest david_l_perry]

Cheers Nigel

[Guest Ian Maycock]

The HP pump takes fuel from the swirl-pot, feeds it to the injectors where some is injected into the engine but the remainder is returned to the swirl-pot. All the LP pump has to do is replace what is used by the injectors. And they don't use much even flat out which they seldom are for more than a few seconds. The LP pump also does the primary fill of the swirlpot and its continuous pumping also blows air out of the top of the pot back to the tank effectively bleeding it.

 

So any pump which can pass three gallons an hour will do. The cheapest facet does 25 US gal per hour so over-spec by about 8 times!

 

Nigel

 

Very different situation if you decide to return fuel from the rail to the tank rather than the swirl-pot. Then you do need a belter of a LP pump.

There is also good reasoning in the placement of the pipes in the swirl-pot. Feed fresh cool fuel to the middle. Take from the bottom. Warm fuel return close to the top and bleed the very top. Not perfect but some warm fuel will be bled from the top of the pot back to the tank. Cold fuel will tend to be dragged down to the HP feed. The pot will stay cooler. The bigger the LP pump the greater this effect.

Thanks Nigel. nice and simple lay man's terms.

[Guest david_l_perry]

2.0l OBP Swirl pot ordered and location sorted next to the tank. Thanks for all the input and help chaps. Just need to sort some brackets and plumb it all in. Should be a fairly simple retrofit I hope.

[Guest david_l_perry]

Swirl pot and Lift pump all fitted right next to the tank - all working. Cheers for the advice and comments chaps

 

 

[Guest david_l_perry]

Quick update on this

 

Had a good run out over the weekend and was purposely running low on fuel to check how this mod performed. No stuttering or fuel starvation even on sharp long bends at all so this has certainly done the trick.

 

Previously even on 1/4 tank I was getting some stuttering on fast bends. Very pleased and not really a big task to sort out.

 

Dave

[Guest 2b cruising]

Nice one Dave. I will now fit one when it comes to my engine change.