Swirl pot setup (pot getting hot)

[K20205 5]

Hi there,

 

i have just plumbed in a swirl pot for my k20 205 and i have a problem,

after a few minutes of running the fuel swirl pot gets really hot and im abit worried,

should the pot be getting hot at all?

 

the ports on the swirl pot are 8mm and im running a 044 pump to feed the engine and using the standard 205 pump to fill the swirl pot.

 

is there a problem with the routing of fuel lines?

its fitted like this

top port= return from main tank

second from top= return from FPR at rail.

3rd from top = feed from lifter pump intank

bottom port= to 044 pump to feed on rail.

[welshpug 1,620]

that's what happens when you pressurise fluids, as you are trying to feed the engine significantly more than it will use its all going back down the return.

 

 

I've no experience of systems like this though, all theoretical, the standard 205 pump is enough on its own at around 180 LPH

 

044 is rated at 285 lph at  3 bar.

[welshpug 1,620]

oh and to give yo a rough idea, 180 lph is said to support aroudn 280 bhp n-a.

[K20205 5]

The only reason why i have ran this swirl pot setup is because the 205 tanks dont have baffles and fuel starves on cornering if the fuel is below a certain point.

 

i might just ditch the swirl pot and use a upgraded fuel pump intank.

[wicked 103 3 Cars]

Try swapping the 2 returns to have less pressure on the return. 

Note that your fuel rail will get hot and works as a heating element on your returning fuel. 

[allanallen 528 2 Cars]

Bigger return from the pot to the tank and a low pressure interrupter type lift pump would be my suggestions.

You’ve currently got a pump capable of 6/7 bar, plus a fairly high flowing fuel return from the engine  feeding the pot and then trying to return to the tank via an 8mm port. There’ll  be a fair bit of pressure in there! 
 

I’m not sure what the effects of a pressurised feed to your high pressure pump are but I imagine it heats things up even more. 
Also the engine return being pressurised May well be effecting your rail pressure. 
 

I thought k20s didn’t run a fuel

return to be honest? 

Edited August 13, 2020 by allanallen

[K20205 5]

1 hour ago, allanallen said:

Bigger return from the pot to the tank and a low pressure interrupter type lift pump would be my suggestions.

You’ve currently got a pump capable of 6/7 bar, plus a fairly high flowing fuel return from the engine  feeding the pot and then trying to return to the tank via an 8mm port. There’ll  be a fair bit of pressure in there! 
 

I’m not sure what the effects of a pressurised feed to your high pressure pump are but I imagine it heats things up even more. 
Also the engine return being pressurised May well be effecting your rail pressure. 
 

I thought k20s didn’t run a fuel

return to be honest? 

I was thinking the same,

i dont remember if i changed my intank pump to a k20 oem one when i was doing the swap, i got a new low pressure pump from a mercedes amg which i can use as a lifter let me see if that makes a difference.

yes you are correct from factory they dont run return but when doing engine swaps its common to use return because everyone uses aftermarket rails

 

 

[Tom Fenton 1,519]

I think the main thing is to increase the return line to the main tank size. As big as you can make it. The pump housing top is plastic, you could probably cut the original return off drill through and fit a bulkhead fitting.

 

Other thing to look at is the lift pump, I think the SPI 205's e.g late 1400's had a lower pressure rated pump that may be more suitable while being a straightforward swap.

[SweetBadger 91]

Interesting, I run exactly the same setup swirl pot:

 

8mm feed / returns

12mm outlet to high pressure pump
 

fuel rail at 3bar

 

with a slightly lower flow high pressure pump: SYTEC OTP020 (210lph). All fed by a Walbro 255 in the tank acting as a lift pump.

 

No issues with the fuel getting too hot.

Edited August 13, 2020 by SweetBadger

[K20205 5]

4 hours ago, SweetBadger said:

Interesting, I run exactly the same setup swirl pot:

 

8mm feed / returns

12mm outlet to high pressure pump
 

fuel rail at 3bar

 

with a slightly lower flow high pressure pump: SYTEC OTP020 (210lph). All fed by a Walbro 255 in the tank acting as a lift pump.

 

No issues with the fuel getting too hot.

Mine are all 8mm including the feed to engine from the 044 pump.

is your fuel pressure regulator connected on the return side of the rail?

 

i dont understand why mine is having this problem, i run 3.5bar pressure so its not that much more than yours..

would the size of the swirl pot matter? Mine looks to be like 1-1.5litre max. 

 

 

[SweetBadger 91]

43 minutes ago, K20205 said:

Mine are all 8mm including the feed to engine from the 044 pump.

is your fuel pressure regulator connected on the return side of the rail?

 

i dont understand why mine is having this problem, i run 3.5bar pressure so its not that much more than yours..

would the size of the swirl pot matter? Mine looks to be like 1-1.5litre max. 

 

 

 

Yes, I run a standard GTi 6 fuel rail and regulator, so regulator is on the return side of the rail. The swirl pot and external pump are mounted under the boot, and the fuel pipe from the pump to the rail is mostly 8mm.

 

The only 12mm pipes are a short 30cm section from the swirl pot outlet to the external pump inlet, and a 40cm section from the fuel filter to the rail.

 

My swirl pot is 1l, I don't think the size of the pot will make any material difference, as once it's full (which won't take long) you see the same flow rates in and out.

 

 

The only issue I had was when I 1st installed it, the external pump was above the level of the swirl pot outlet up against the boot floor. The efi pumps must be gravity fed or be positively supplied with fuel, so this still resulted in cavitation and fuel surge when the in tank pump lost it's fuel supply.

 

Dropping the pump to below the level of the swirl pot outlet solved this issue.

 

Edited August 13, 2020 by SweetBadger

[K20205 5]

3 hours ago, SweetBadger said:

 

Yes, I run a standard GTi 6 fuel rail and regulator, so regulator is on the return side of the rail. The swirl pot and external pump are mounted under the boot, and the fuel pipe from the pump to the rail is mostly 8mm.

 

The only 12mm pipes are a short 30cm section from the swirl pot outlet to the external pump inlet, and a 40cm section from the fuel filter to the rail.

 

My swirl pot is 1l, I don't think the size of the pot will make any material difference, as once it's full (which won't take long) you see the same flow rates in and out.

 

 

The only issue I had was when I 1st installed it, the external pump was above the level of the swirl pot outlet up against the boot floor. The efi pumps must be gravity fed or be positively supplied with fuel, so this still resulted in cavitation and fuel surge when the in tank pump lost it's fuel supply.

 

Dropping the pump to below the level of the swirl pot outlet solved this issue.

 

I have just been to the garage, i removed the intank fuel pump and its a gss342 and i replaced it with a low pressure one just to test it, now its not that bad but the 044 is sounding very loud when running, i guess my problem might be where its placed, its higher than the swirl pot outlet.

the pot didnt get as hot as last time and engine was running for around 15-20mins..

 

tomorow ill place the pump it lower down and see how that goes.

 

thanks 

 

 

[SweetBadger 91]

Sounds like progress, don't run that 044 pump if it's running louder - noise likely to be due to cavitation as the 044 is struggling to draw fuel from the pot - this can damage the pump.

 

It definitely needs to be at the same height or lower than the swirl pot outlet. If it's higher, then as soon as the level in the pot drops lower than the pump, the pump won't have a +ve pressure fuel supply and you'll get cavitation.

 

That Walbro pump is the same as the one I run - 255lph

 

I'm still yet to be convinced that the high pressure pump in the main tank is the issue here - there's a high volume of fuel in the main tank, which should be constantly pumped in and out of the swirl pot -> the fuel in the swirl pot should be the same temp as the fuel in the main tank. Is that also getting hot? If it's all plumbed in correctly the swirl pot should be at about the same temp as the fuel in the main tank.

 

Edited August 13, 2020 by SweetBadger

[petert 549]

I run an 044 along with an oem  fuel pump as the pre-pump, along with standard lines. It is very noisy but the swirl tank doesn't get hot. It's been like that for over five years.

 

It absolutely must be gravity feed into the 044.

 

Also check you don't have a Chinese copy 044. Just google. It's been well documented.

 

As you're probably aware, if you're generating any useful amount of G force, the standard tank is inadequate and you need some type of swirl pot tank to feed a second pump. The 044 isn't excessively big and won't by itself generate any more heat than another pump under the same load. The 044 is reliable and that's what you need. Once my helmet is on, the noise goes away.

Edited August 14, 2020 by petert

[wicked 103 3 Cars]

On 8/12/2020 at 7:46 PM, K20205 said:

its fitted like this

top port= return from main tank

second from top= return from FPR at rail.

3rd from top = feed from lifter pump intank

bottom port= to 044 pump to feed on rail.

 

On 8/13/2020 at 3:34 AM, wicked said:

Try swapping the 2 returns to have less pressure on the return. 

 

 

Did you try swapping the outlets??

 Like this:

 

top port= return from FPR at rail.

second from top= return from main tank

3rd from top = feed from lifter pump intank

bottom port= to 044 pump to feed on rail.

 

Then you don;t need much pressure in the swirl tank to drain back to the main tank, but still have sufficient fuel above the 044 port. 

Will make life easier for the intank pump.

 

That is also how I have it in mine, using a base model (1.4?) injection pump to in the tank. 

[K20205 5]

2 hours ago, wicked said:

 

 

Did you try swapping the outlets??

 Like this:

 

top port= return from FPR at rail.

second from top= return from main tank

3rd from top = feed from lifter pump intank

bottom port= to 044 pump to feed on rail.

 

Then you don;t need much pressure in the swirl tank to drain back to the main tank, but still have sufficient fuel above the 044 port. 

Will make life easier for the intank pump.

 

That is also how I have it in mine, using a base model (1.4?) injection pump to in the tank. 

Ill try that and see if it makes a difference.

thanks mate

[K20205 5]

All done guys, 

thank you for your help,

the whole problem was the location of the 044 pump, i made a bracket and made it at the same level as the lower port of the swirl pot now everythings running sweet,

the pump is sounding nothing like how it was, its very quite.

 

thanks again