Fuel swirl pot
Discussion
A concern with my install is that one carter pump may not have enough flow in WOT conditions, so I want to be able to switch both pumps on and return to both fuel tanks at the same time. I am checking the flow rate on the carter pumps so that if needs be I will upgrade them. I can't run the risk of leaning out especially as it's supercharged.
The flow at idle I described earlier is not so much of a problem for me as I have installed a pump speed controller which below a preset RPM it reduces the pump speed therefore flow, but maintains pressure. The RPM level is adjustable and there is an override switch.
Oh! to have one big fuel tank with a sump in the bottom, life would be so much easier!
>> Edited by CanAm Dave on Sunday 27th November 11:22
The flow at idle I described earlier is not so much of a problem for me as I have installed a pump speed controller which below a preset RPM it reduces the pump speed therefore flow, but maintains pressure. The RPM level is adjustable and there is an override switch.
Oh! to have one big fuel tank with a sump in the bottom, life would be so much easier!
>> Edited by CanAm Dave on Sunday 27th November 11:22
I don't think you're likely to have a problem with the Carter pumps unless you start developing crazy horsepower. The Carter pumps are good for 600 bhp according to Ultima (Stig ran this with no problems with his supercharged 630ish engine)...and this is at 7 psi. Your surge tank will be at 0 psi so you can bet that the fuel flow is going to be close to their rated 100 gallons(us)/hr capacity.
That said I have heard it suggested that running the surge tank with a slight restriction in the return line to the fuel tank is a good idea. This is because it gives something for the low pressure pumps to push against which reduces the chances of them burning themselves out.
I agree with Phil that swirl in a fuel swirl pot is over rated. Once the system has bled itself what little vapour there is will naturally migrate to the return pipe to the fuel tank.
That said I have heard it suggested that running the surge tank with a slight restriction in the return line to the fuel tank is a good idea. This is because it gives something for the low pressure pumps to push against which reduces the chances of them burning themselves out.
I agree with Phil that swirl in a fuel swirl pot is over rated. Once the system has bled itself what little vapour there is will naturally migrate to the return pipe to the fuel tank.
canam-phil said:
How about Pollack valves? I have used them on GT40s in the past.
They are used in the bio-fuel cars and are for petrol. Also, they are not solenoid, they are motor driven so no heat problem. They make the return flow to the correct supply tank so easy.
I have some in stock.
>> Edited by canam-phil on Saturday 26th November 18:17
My GTR has twin tanks and twin low pressure pumps linked to a swirl pot by a Pollock switching valve, although mine is a solenoid type. The fuel injection pump draws from the base of the swirl pot with fuel return to the top. I bought the Pollock valve from Eurospares and it works just fine (good for 60psi I believe, but because it is on the low pressure side of the setup it only has to deal with about 5psi max)) The only downside is that it has push on fittings, but with decent hose finishers it looks fine.
GTRMIKIE says the valve he uses is a solenoid type. The Pollack valve is a motorised valve that needs driving each way by reversing the polarity.
The motorised valves are driven into position by an electric motor and are stable in either position. They only draw power for a fraction of a second during transfer. A switch in the valve shuts off the motor when the valve reaches the selected position. Another switch within the valve provides automatic fuel gauge readout for the selected tank.
It's that type that I am using on my Canam for the return from the swirl pot.
Europaspares has them on this page
https://secure.visav.co.uk/avshop/products.asp?getcats=true&cat=32&scat=75
The motorised valves are driven into position by an electric motor and are stable in either position. They only draw power for a fraction of a second during transfer. A switch in the valve shuts off the motor when the valve reaches the selected position. Another switch within the valve provides automatic fuel gauge readout for the selected tank.
It's that type that I am using on my Canam for the return from the swirl pot.
Europaspares has them on this page
https://secure.visav.co.uk/avshop/products.asp?getcats=true&cat=32&scat=75
canam-phil said:
GTRMIKIE says the valve he uses is a solenoid type. The Pollack valve is a motorised valve that needs driving each way by reversing the polarity.
The motorised valves are driven into position by an electric motor and are stable in either position. They only draw power for a fraction of a second during transfer. A switch in the valve shuts off the motor when the valve reaches the selected position. Another switch within the valve provides automatic fuel gauge readout for the selected tank.
It's that type that I am using on my Canam for the return from the swirl pot.
Europaspares has them on this page
https://secure.visav.co.uk/avshop/products.asp?getcats=true&cat=32&scat=75
Phil, I assumed my valve was a solenoid type because it switches so quickly, but I'm sure we are talking about the same valve (mine also has the fuel gauge connections, although I didn't use them, and I bought it from Europaspares) so I bow to your superior knowledge!
GTRMikie said:
Phil, I assumed my valve was a solenoid type because it switches so quickly, but I'm sure we are talking about the same valve (mine also has the fuel gauge connections, although I didn't use them, and I bought it from Europaspares)
Mikie, you are right, they are quick and also quiet. I don't like the continuously energised solenoid type - no reason other than a motorised valve sounds a better engineering solution. I'm using it only on the "return to tank side" from the swirl pot ie low pressure so well withing spec for the valve and flow is fine through the valve? Thats my solution so push on fittings and clips is OK. It would be better if they had AN fittings but cant have everything!
I've just purchased the ITC305 swirl pot from ATL that was mentioned below. What's a bit wierd is that the part that arrived is different from both the description CanAmDave gave below, the 2005 and 2006 Demon Tweeks catalogues! That said what has arrived suits my purposes more than the listed part so I'm not complaining! First off here's a picture:
The connectors are -8 fuel pump outlet at the bottom, 2 x -6 swirl inlet, 1 x -6 swirl outlet and a -6 bleed on the top. The Demon Tweeks catalogues don't mention the swirl outlet and the 2005 catalogue talks about a -4 bleed.
The connectors are -8 fuel pump outlet at the bottom, 2 x -6 swirl inlet, 1 x -6 swirl outlet and a -6 bleed on the top. The Demon Tweeks catalogues don't mention the swirl outlet and the 2005 catalogue talks about a -4 bleed.
Hi Dave
It's the same as mine! The mistake in my description was the bleed in the top which as you say is a -6 not a -4 as it says in the catalogue.
For my needs I have removed the -8 outlet and welded in a -10 fitting.
It drops to -8 after my pump. The pump I have just works better with a -10 feed.
Have you thought any more about the carter pumps running flat out due to no regulation? How are you going to over come this?
Dave
>> Edited by CanAm Dave on Sunday 4th December 11:36
It's the same as mine! The mistake in my description was the bleed in the top which as you say is a -6 not a -4 as it says in the catalogue.
For my needs I have removed the -8 outlet and welded in a -10 fitting.
It drops to -8 after my pump. The pump I have just works better with a -10 feed.
Have you thought any more about the carter pumps running flat out due to no regulation? How are you going to over come this?
Dave
>> Edited by CanAm Dave on Sunday 4th December 11:36
Hi,
No worries about your description. Demon Tweeks should know better though. Their catalogue is always full of mistakes and half-filled out specs...
The sooner Summit or JEGS open up a UK branch to give them a bit of much needed competition the better IMHO.
Not got an answer to this at the moment. I was going to build my system without any restrictions and see how the pumps sounded compared with running the carbs. One possibility I've thought about is a progressive pump controller. The Megasquirt ECU I'm using should be able to output a PWM stream to drive the pump(s) slower under low demand conditions and ramp it up when required. Might require a bit of hardware and software hacking to get running though.
Dave
No worries about your description. Demon Tweeks should know better though. Their catalogue is always full of mistakes and half-filled out specs...
The sooner Summit or JEGS open up a UK branch to give them a bit of much needed competition the better IMHO. CanAm Dave said:
Have you thought any more about the carter pumps running flat out due to no regulation? How are you going to over come this?
Not got an answer to this at the moment. I was going to build my system without any restrictions and see how the pumps sounded compared with running the carbs. One possibility I've thought about is a progressive pump controller. The Megasquirt ECU I'm using should be able to output a PWM stream to drive the pump(s) slower under low demand conditions and ramp it up when required. Might require a bit of hardware and software hacking to get running though.
Dave
I've not been having a lot of luck getting hold of a fuel selector valve to finish off my EFI installation. I tried getting the 3-port selector from Europa Spares that were linked to in this thread before Christmas. Got a form email back sometime after I'd placed the order saying that they no longer stocked the item... (WTF were they listing it in their catalogue for if they don't stock it!!! 
). They might still stock the 6-port pollack valve but I'm disinclined to try them again...
Anyway. I've discovered another source. Turns out that folk who use biodiesel also need to be able to swap between regular diesel for starting and the gloopier vegetable oil for normal running. There's a company that's able to provide all of the parts you require including...pollack valves for quite a reasonable price: www.biotuning.co.uk
). They might still stock the 6-port pollack valve but I'm disinclined to try them again... Anyway. I've discovered another source. Turns out that folk who use biodiesel also need to be able to swap between regular diesel for starting and the gloopier vegetable oil for normal running. There's a company that's able to provide all of the parts you require including...pollack valves for quite a reasonable price: www.biotuning.co.uk
Have just sent off the drawings for a Swirl pot I'm having made. The guy sell alot of stuff on Ebay, asked him about one off's and he was happy do anything as long as I supplied a drawing....
Am running out of room in the engine bay so will be mounting the 2 Bosche pumps off the swirl pot... Will post a Pic when it arrives back..
You need a selector valve ? than I take it your running seperate tanks then ??
Am running out of room in the engine bay so will be mounting the 2 Bosche pumps off the swirl pot... Will post a Pic when it arrives back..
You need a selector valve ? than I take it your running seperate tanks then ??
Heres one of the guy's sales on Ebay... But he can make any shape tank you want with pushon or Jic fittings.....
http://cgi.ebay.co.uk/ALLOY-FUEL-SURG
http://cgi.ebay.co.uk/ALLOY-FUEL-SURG
gtrclive said:
Am running out of room in the engine bay so will be mounting the 2 Bosche pumps off the swirl pot... Will post a Pic when it arrives back..
Be interesting to see that.
gtrclive said:
You need a selector valve ? than I take it your running seperate tanks then ??
Yep. Keeping the stock Carter's as low pressure pumps and both tanks separate. Doing allows me to balance the car better...
davefiddes said:
Anyway. I've discovered another source. Turns out that folk who use biodiesel also need to be able to swap between regular diesel for starting and the gloopier vegetable oil for normal running. There's a company that's able to provide all of the parts you require including...pollack valves for quite a reasonable price: www.biotuning.co.uk
Dave, that's a b****y good price, I paid over £70 for the same valve from Europa Spares!
I must admit, I didn't have any trouble with fuel pickup on the track either. In fact, I ran the car all weekend with less than 2 gallons in the tank! Maybe my fuel sender is stuck. Ha. I only got fuel starved one time when I rolled onto the throttle going down a straight. Went into the pits, filled it back up with fuel, and was good to go again. I'm running EFI though.
Cheers!
-Mack
Cheers!
-Mack
jschwartz said:
Why is it neccesary to make such a complex fuel system?
I've got one Holley inline EFI pump good for 800 hp. No swirl pot.
Broken track records with the car, so I'm driving plenty fast. No fuel delivery problems ever.
Jeff S
I believe that this particular query has come up before. I've just dug out the info I received from American Speed concerning the EFI installation for my engine. It says "----Do not run fuel through any auxillary fuel pumps or reservoirs (collection tanks). Run a line from each tank to a "T" and then into the fuel pump. Keep it simple.----" IIRC the factory told me the same thing.
The complications arise when you have two tanks and two fuel pumps operating independently. You must return excess fuel to the tank from which it is being pumped. If you don't, there is a real risk that the other tank could overflow. I looked long and hard at using a solenoid valve but decided against it and went for a simpler system of using two shut-off valves wired to LED's on the dash. It should work OK but haven't had the engine running yet.
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