Hi Guys,
It's not an intentionally negative title, but have just been thinking about fuel swirl pots, and i'm either just being thick or missing the
point.
Now firstly, i did actually fit one to my last car, so certainly not against them.
Ignoring filters, here's the perceived setup:
Fuel Tank --> Fuel Pump --> Swirl Pot --> Fuel rail
So, my understanding is that the swirl pot is there to stop starvation when cornering hard.
However, if you are feeding to a swirl pot, which then feeds to the engine, what happens under hard cornering?
To my mind, the pump still can't find the fuel from the tank, which means it can't push to the swirl pot, which means nothing also comes out
of the swirl pot as this needs to be full to work properly?
So unless the pump can just pump air into the swirlpot which in turn pushes the fuel to the engine, i don't get it!
Like i said, probably being thick, but someone please enlighten me!
Cheers,
Andy
The swirl pot is filled from the top and the fuel taken from the bottom to the rail - so it would need to be a pretty long corner to fully empty the
swirl pot and thus starve the engine of fuel. Have you got your swirl pot plumbed and mounted to achieve this ?
edit to say in a fuel injected engine the set up is usually : tank > LP pump > swirl pot > HP pump > injector rail.
[Edited on 16/12/16 by wylliezx9r]
Archaic hangover from carb systems which used a carb-side pump and could pull from the pot. No point on a fuel injected system unless you have two pumps (one filling a feeder pot, the second sucking from that into a primary pump) - better off putting a small sump or baffling in the tank to stop it.
2 fuel pumps, 1 feeding the swirl pot which then bleeds back to the tank. Then high pressure pump after the swirl pot to fuel rail returning to the swirl pot!
Which is a lot of extra faff and fault optiosn when you could just stick foam in your tank.
Ahhh,
Yep as predicted i'm being an idiot!
I forgot about the 2 pumps and i'm sure that's exactly how i had my last car setup - LP feeds the pot, HP feeds the engine.
That was pretty straight forward!
Cheers,
Andy
I'm with coyoteboy on this one. It's a lot of extra complication for little gain over a sumped+baffled tank.
But foam breaks down and clogs up filters if you're lucky and injectors if you're not. Foam will leave you stranded at the most inopportune moment plus decreases capacity of your tank, which is probably only an issue if you're using a small tank on a track car.
Thanks guys,
I think for now i might keep it simple and just high pressure straight to the fuel rail, it's stock ignition on a blacktop zetec, so should be
ok.... i'll look into pots and tanks a bit further down the line unless one appears for a nice price!
quote:
Originally posted by Texan
But foam breaks down and clogs up filters if you're lucky and injectors if you're not. Foam will leave you stranded at the most inopportune moment plus decreases capacity of your tank, which is probably only an issue if you're using a small tank on a track car.
If you have an injection tank (with swirl pot built in) then there is no point. If you are converting a Carb set-up you already have the LP lift pump and tank so it is a simple(ish) job to convert to FI using a external switl pot/HP pump and a return line to the tank.
Well i'm actually converting from a CVH and was running off the engine fuel pump, so not quite as simple, but in the grand scheme not difficult to plumb in....
My first fuel setup was an unbaffeled rectangular tank and silver top pump to carbs.
Tank lower than 1/3rd full and every roundabout It would splutter and misfire a few meters down the road as the carb bowls emptied, added a large
Filter King and added a few meters.
Tank - LP cube pump - Swirlpot - High flow Silvertop to Filter King
Running the tank return from the highest but one point on the swirl pot (highest one is usually the air bleed) means there is always fuel in the swirl
pot and give an extra litre when the tank ran dry on the A14 run.
The slowest I have ever driven in the kit.