Swirl Pot

[greyV8pete]

Re: Swirl Pot

Hi Peter I know a man who make one for you to any design you want, and with any outlet/inlet size you want in alloy ? And it won't be a fortune.

Many thanks Lee & Danny. I will bear your comments in mind once I have exhausted all my checks and deliberations. Peter.

[greyV8pete]

Re: Swirl Pot

Further to my above I've checked the outlet pipe to high pressure pump and it does appear to turn toward the bottom of the swirl pot. Exactly how far down it goes I can't make out via my simple examination but at least it doesnt seem to get its supply only if the swirl pot is full.

Using a curved piece of thin wire with a 1mm “lip” bent up at the end I have found that the HP supply pipe is bent into a radius and inside my swirl pot it reaches "diagonally" downwards almost to the bottom of the tank. I will check next how long the other three pipes are. However they all point down a bit and unfortunately towards the same place that the HP pump feed comes from so any air bubbles that are ejected from the LP supply pipe could easily be sucked straight into the HP feed! There really needs to be a baffle in there so the HP pump feed is drawn from non-aerated fuel. Peter.

[greyV8pete]

Re: Swirl Pot

Another thought has just occurred to me. When I had my “rich running saga” a few years ago one of the many things that I replaced was the LP fuel pump. At the suggestion of the supplier (I forget who now) I replaced the Silver Top one with a Red Top version as this was recommended for a Rover V8. As this has a higher flow (and higher delivery pressure if constrained by a carb) I am wondering if there is generally too much unneccessary flow of fuel in the LP pipes & swirl pot for my application? Peter.

[dogoncrazy]

Re: Swirl Pot

Gentlemen,
I think we are missing an important point here. If we have a swirl pot with stubs that are 10mm od and we fit a pipe to that then the pipe presumeably is also 10mm INTERNAL not 8mm.
A 12mm MAY be necessary under race conditions in order to get the flow rate, but as Danny suggests there are plenty of cars out there that have the same swirl pot /tank connectors and apparently have not encountered any problems with fuel delivery.
I suggest we are creating an answer to a problem that essentially doesn't exist. We can't fill the bath from an empty bucket if you get my drift!

[Mike]

Re: Swirl Pot

Gentlemen,
I think we are missing an important point here. If we have a swirl pot with stubs that are 10mm od and we fit a pipe to that then the pipe presumeably is also 10mm INTERNAL not 8mm.
A 12mm MAY be necessary under race conditions in order to get the flow rate, but as Danny suggests there are plenty of cars out there that have the same swirl pot /tank connectors and apparently have not encountered any problems with fuel delivery.
I suggest we are creating an answer to a problem that essentially doesn't exist. We can't fill the bath from an empty bucket if you get my drift!

Alan

You may well be right, but Sytec, and Dane's expert both advised running minimum 12mm feed pipes to the HP pump, so why not do it if you can?
My HP pump is rated at 385 litres per hour = 6+ litres per minute - I doubt you can get that kind of flow through 8mm. I think it is very likely that mine was cavitating. I hope to start it up again soon, so I'll let you know what happens.

Mike

[greyV8pete]

Re: Swirl Pot

Gentlemen,
I think we are missing an important point here. If we have a swirl pot with stubs that are 10mm od and we fit a pipe to that then the pipe presumeably is also 10mm INTERNAL not 8mm.
A 12mm MAY be necessary under race conditions in order to get the flow rate, but as Danny suggests there are plenty of cars out there that have the same swirl pot /tank connectors and apparently have not encountered any problems with fuel delivery.
I suggest we are creating an answer to a problem that essentially doesn't exist. We can't fill the bath from an empty bucket if you get my drift!

Just to clarify. My stubs are 10mm Outside diameter but 8mm Bore. It has always been quite a struggle to fit new pipes without warming them as the stubs are plain duralumin tube with squared off ends, albeit chamfered off by me to assist fitting. All the feed and return hoses are also 8mm bore.

Incidentally I have a glass filter just before the HP pump. After being disturbed for cleaning there is sometimes a small air bubble in it but that soon dissappears after a short run. If there was cavitation before the pump wouldn't there be bubbles visible in the filter if that happens? Just a thought. Peter.

[dogoncrazy]

Re: Swirl Pot

Apologies but i don't really get why you are using 8mm bore pipe on 10mm stub? Incidently my car ran perfectly today with fuel in tank.

[greyV8pete]

Re: Swirl Pot

My swirl pot has the side outlet to the HP pump extended down inside the swirl pot towards the inner lower corner . All other pipe connections are short stubs that finish inside just beyond the weld.

To improve the circulation and allow any bubbles to rise clear of the HP pick up I have changed the front pipe connections as follows:

Swirl Pot Conns.jpg

Numbering from the top of the photo,

1 Return to Tank
2 Return from Fuel Rail / Fuel Pressure Regulator
3 L/P Pump Supply

My original front pipe connections were originally as follows.

1 L/P Pump Supply
2 Return to Tank
3 Return from Fuel Rail / Fuel Pressure Regulator

For those who have the same Marlin swirl pot, how does this compare with your connections?

Peter.

[Dane_Rescueman]

Re: Swirl Pot

Hi guys. I have lost the picture I have of my swirl pot but I have the rendered Turbocad drawing that I sent to the supplier with my requested pipe outlets. The top is the 6mm vent back to the tank. The next one down is an 8mm pipe connected to a red top solid state priming pump 9the larger road/rally one). Third down is an 8mm return from the fuel pressure regulator and the bottom one is the 12mm outlet to the HP pump. It is mounted forward of the rear axle against the little rear bulkhead in the Berlinetta. It was welded up out of ally and semms to be taking whatever strain it is subjected to!

[greyV8pete]

Re: Swirl Pot

Hi guys. I have lost the picture I have of my swirl pot but I have the rendered Turbocad drawing that I sent to the supplier with my requested pipe outlets. The top is the 6mm vent back to the tank. The next one down is an 8mm pipe connected to a red top solid state priming pump 9the larger road/rally one). Third down is an 8mm return from the fuel pressure regulator and the bottom one is the 12mm outlet to the HP pump. It is mounted forward of the rear axle against the little rear bulkhead in the Berlinetta. It was welded up out of ally and semms to be taking whatever strain it is subjected to!

Hi Dane. Is your HP pump also at the rear next to the swirl pot, i.e. do you have HP fuel in the line from the HP pump to the fuel rail? And is the HP feed from the pump to the fuel rail 12mm or 8mm? Peter.

[Dane_Rescueman]

Re: Swirl Pot

Hi Pete, I managed to obtain the old Sierra steel cage that houses the HP pump and the large, full flow HP fuel filer which on the Ford system is on the outlet side of the HP pump. This cage is bolted to the chassis on the LHS rear just forward of the swirl pot. The 12mm flexible pipe from the swirl pot to the HP pump is around 300mm long - not far. The pressurised fuel then goes to the engine bay via 8mm copper pipe thence to the fuel rail via an armoured flex pipe. The copper pipe , flex pipe and the push on connectors came as a kit of bits from Tifosi. It is the LP input to the HP pump that the tuning guys have an issue with. They say it must be at least 12mm which mine is. I run my system at 3 bar on the gauge fitted to the fuel pressure regulator which is after the fuel rail on this Bosch/Ford system. I have had no leaks or misfires since I cleared out a load of goop collected in my filters early on over a year ago.!!!

[greyV8pete]

Re: Swirl Pot

Hi Pete, I managed to obtain the old Sierra steel cage that houses the HP pump and the large, full flow HP fuel filer which on the Ford system is on the outlet side of the HP pump. This cage is bolted to the chassis on the LHS rear just forward of the swirl pot. The 12mm flexible pipe from the swirl pot to the HP pump is around 300mm long - not far. The pressurised fuel then goes to the engine bay via 8mm copper pipe thence to the fuel rail via an armoured flex pipe. The copper pipe , flex pipe and the push on connectors came as a kit of bits from Tifosi. It is the LP input to the HP pump that the tuning guys have an issue with. They say it must be at least 12mm which mine is. I run my system at 3 bar on the gauge fitted to the fuel pressure regulator which is after the fuel rail on this Bosch/Ford system. I have had no leaks or misfires since I cleared out a load of goop collected in my filters early on over a year ago.!!!

Many thanks for the info Dane. I am not familiar with Sierra injection parts so a photo would be useful for future reference if you have one to hand. However as my FPR has worked up until now I have moved into another train of thought. I have just fitted a new OE fuel pressure regulator and first impressions are that pick up and acceleration are far more precise. However the bad news is that after a run of about 10 miles yesterday and after a fair bit of traffic queueing the hesitation returned when pressing the accelerator more than a fraction. I recently bought an Ecumate diagnostic gadget and on the AFM screen it has flagged up Limp Home / No Cats! Although I don’t have cats I do have OE Lambda sensors and the correct White tune resistor. There are no fault codes stored so I am none the wiser. With Stoneleigh fast approaching I am beginning to run out of ideas. Peter.

[CosworthCabrioLee]

Re: Swirl Pot

Peter when was the last time you reset your ECU ?

[greyV8pete]

Re: Swirl Pot

Peter when was the last time you reset your ECU ?

ECU reset automatically recently as I disconnected the battery when working on the diff job / fuel tank.

I have just found the following link:

http://www.pistonheads.com/gassing/t...imp+No+CATS%22

Think I will see what the Ecumate says when the engine is runing, then check out the integrity of the tune resistor, its connector plug and all wiring back to the ECU. It’s a bit of a birds nest down there in the passenger footwell so could have easily been dislodged! Then will do an ECU reset. Peter.

[CosworthCabrioLee]

Re: Swirl Pot

Also Peter it is worth noting that some of the cheaper code readers do not pick up fault codes, I spend a bit of time at my local garage and some cars that have faults are not picked up with one reader but another reader get it. It might be worth popping into the a garage and getting it plugged in as it may save you a load of time and soul searching. Shame you live so far away could of done it for you at the garage.