Swirl Pot?

mickjo · Post by **mickjo** » Mon Jun 22, 2009 5:35 am

I'm replacing my Triumph engined stag for a rover 3.5 with megasquirt. So as I understand it I will need to replace the LP stag fuel pump for a HP fuel pump with a pre pump filter and pre injection filter, which is nice. However after reading up on the tinterweb I believe I might need a swirl pot. so the system will now include the stag lp pump to supply the swirl pot first, before the pre pump filter etc etc. Is that correct? Do I need the swirl pot?
Hope you can enlighten me on this, the car is going to be purely a road going beast with a bit of poke no starsky and hutch stuff.
Mick

Post by **katanaman** » Mon Jun 22, 2009 9:51 am

yes you will need a swirl pot/sump or your engine will cut going round corners when the fuel gets lower. You could include it in the tank and dispense with the 2 pumps. I don't know the car or the room you have but if you have room you could even put a sump under the existing tank which would save the LP pump as well.

ian.stewart · Post by **ian.stewart** » Mon Jun 22, 2009 12:58 pm

mm, time to disagree,

Ive been running my injected engine without a swirl pot, all I run is a big fuel filter, [Audi V8] and a pump, both mounted just below the level of the tank, with the pickup mounted at the back of the tank, Look under plenty of production cars that run external pumps, and you will find not many run swirl pots from the factory,

mickjo · Post by **mickjo** » Mon Jun 22, 2009 2:11 pm

Thats interesting Ian as the tank is in the boot I could fit the pump in the well to the right of the tank where the spare wheel is, I'm sure I can make it fit. I've also been told that if I keep the tank at least 1/4full then it should eleviate the need for a pot as well. Any thoughts on a good H.P. pump? seen some on ebay for about £50+P/P.
Thanks to both Katanaman and Ian for your thoughts.

Mick

Post by **katanaman** » Mon Jun 22, 2009 2:57 pm

You must have taken more tanks apart than me Ian because every injection car I have opened the tank on has had a pot inside it. Certainly all the fords have had them. Depends on the tank shape I suppose. The old across the back seat type like the escorts probably have a good chance because they are tall and thin. The under the boot floor flat ones like the Capri (which do have swirl pots) will have problems. I converted an escort Van to XR3I engine and when it went bellow 1/4 tank it cut out on the corners. I ended up putting the Diesel tank in since it was the only van tank that had the pot inside. In effect with the big low mounted filter your running a sump Ian.

mjheathcote · Post by **mjheathcote** » Fri Jul 03, 2009 2:54 pm

I'm fuel injecting my Stag, but the Triumph Engine not Rover, but I still have the same problem of course.
I'm thinking of using a swirl pot fed by a LP pump, but I believe the standard SU pump would overheat not being designed to run continuously when feeding a swirl pot, effectively being open ended return into the fuel tank. If I am wrong here please let me know, it will save me a few pennies!

Talking to other EFI Stag owners the solutions used have not been elegant really. No swirl pots, Range Rover pumps screwed into the top of the original tank, again with no swirl pot.
I have not seen a nice one converted in this area yet.

Cheers,
Mike

Ian Anderson · Post by **Ian Anderson** » Fri Jul 03, 2009 4:31 pm

One of the "neatest" ideas I saw was one sold in USA for Bronco conversions for serious offroading (45 degree plus stuff!)

It was a fuel filter (That was about 1 liter in size) that was fed from the low pressure pump (The unit was chrome and to change the filter the whole outside was unscrewed from the mounting bracket in a similar way as an oil filter came off)

The HP pump "suction" side went out the top direct to the HP Pump and the return from the HP / rail came back to the filter and then the lase outlet was the overflow from the filter unit back to the tank (If needed)

What I liked about this was it was a good size filter and swirl in 1 neat unit - what I didn't like was that I could not find anywhere in the GT40 for it to fit!

But I'm damed if I can find the link now -I'll keep searching

Ian

Ian Anderson · Post by **Ian Anderson** » Fri Jul 03, 2009 4:36 pm

Found it

http://www.bcbroncos.com/store/advanced ... uel+filter

But now the filters are not chromed!

Ian

Post by **demo2** » Sun Jul 05, 2009 1:54 am

Im with ian on this, my tina hasn't got a swirl pot, just a big filter and mine never cuts out either

CastleMGBV8 · Post by **CastleMGBV8** » Sun Jul 05, 2009 9:33 am

Ian,

Thanks for posting that link, I use to have in my favourites but it went missing, there are a lot of people whio have used that set up sucessfully and it's a lot simpler and cheaper than the other alternatives and what I'll do in the MGB when I get round to fitting the EFI.

Kevin.

andyv8van · Post by **andyv8van** » Sun Jul 05, 2009 10:23 pm

Ian

sounds just what i have been looking for as well....

will run my current red top fuel pump and then run the injection pump from that.Still need to plumb the fuel return pipe in some how.

I guess you can just plumb the fuel pump in and remove the in line filter since you are using a filter anyway...cool

will have to order one for my van fuel injection system.

Andy