Seperate Swirl Pot

[Plums]

Originally Posted by sambo

Warren, here's a picture of my VZ Crewman pump. Sounds very similar to the Ford unit you're describing - certainly no O ring or circlip involved. More pics in my gallery.

In the standard set-up, the LS pumps have a large o-ring that seals against the tank and it's all held in place by a big circlip. The Crewman pumps look a bit different because the return plumbing happens inside the unit, as opposed to other models that come out through the filter then return to the regulator inside the unit.

[boxhead]

Originally Posted by WKB

The Harrison cobras have a setup that utilises the fuel pump from a BA/BF Falcon(similar to the VT/VZ Commodore) straight into the fuel tank the way Sideshow discribed. Mine was one of the first few tanks they started to use this idea which used a commodore pump before they changed over to one from a falcon. I used a V8 ute pump which fitted a bit easier.

I would fit the falcon pump over the holden pump as the falcon unit is a lot easier to fit. The falcon uses five screws to hold it in position with a cork gasket and holden uses a large O ring and circlip.

In the picture of the swirl tank and pump that Rebel attached, the pump is a BA/Bf falcon unit.

Warren

My setup is definatly a VT V8 pump and when Mike made the swirl pot instead of using the factory circlip arangement he made it a sandwich plate system the same as the one pictured by Rebel.

[C0braed]

Originally Posted by boxhead

I agree with you there, I initialy only set it up that way wanting to be able to get every last drop of fuel from the tank, and I have similar issues as Gregg is describing in hi speed cornering and accelerating when the tank is below about 1/4 full, I was thinking that by returning the fuel to the swirl pot then atleast it is not getting sloshed around in the tank and missing the intank pick up.
I figured I was not chassing every single last bit of HP so the small loss due to warm fuel did not bother me.

All feed and return lines to and from surge tank are the same size, being 8mm ID

The thing with returning fuel to the surge tank is that under full throttle or anything apart from idle is that less fuel is returned to the tank so in effect you will get little gain from it, at idle the engine is using less fuel and the return volume is at its highest and the lift pump should not be having any troubl supply the tank. The problem I have found with most surge tanks I have seen is that they usually have a -6 or -8 supply into them from the lift pump and the same size -6 or -8 as the return to the tank and then the have a -6 or -8 return into the surge tank for the returned fuel, so in effect you have double the supply into the tank but only half the area for returning to the tank. This in effect especially at idle will create pressurization of the surge tank and will apply pressure to the back of the regulator which can cause a richer than normal idle.

[Aussie Mike]

I reckon a bit of pressure in the surge tank is a good thing. I would even reccomend putting a restrictor in the return line to create a few PSI of possitive pressure in the surge tank.

The way I've got mine set up I have a #6 line from the in tank lift pump. This is a low pressure in tank pump from a VL commodore. I have a #6 return from the swirl pot but I've piece of brass in the line with a hole drilled in it to provide a bit of restriction. The feed from the swirl pot is a #8 line and it goes into the fuel filter and from the filter to the Bosch 044. There's a 1/2" line from the bosh 044 to the back of the left fuel rail and a crossover to the other rail. On the back of the right fuel rail there is a line to the regulator. The regulator bleeds off pressure to a #6 line back to the swirl pot.

There's also a check valve on the output of the 044 that stops fuel draining back trhu the pump when the car is sitting. It starts first turn of the key.

Here's a pic of the swirl pot looking from under the car (The pic is the wrong way round so it's a bit confusing)



The fuel lines running up the tunnel and you can see the reg on the firewall. the 3rd line is for the purge on the carbon canister.



Here's the fuel pump mounted on the underside of the boot floor. Not a position I would reccomend as the boot cavity makes the sound resonate even worse. You can see the check valve on the output.



Cheers

[C0braed]

nothing wrong with pressure in the surge tank but if it is connected to your regulator return line then that is pressure working on the back of the regulator as it then becomes a closed loop from the pump outlet to the return into the tank.
On another note your fuel lines could need some more clamps as I think the regs call for a clamp/support every 300mm

[Aussie Mike]

OK, that makes sense. I don't imagine it should be a problem as long as the pressure in the swirl pot was less than the pressure at the rails. LS1 runs at 4 Bar at the rails where most Ford fuel systems run at 3 Bar.

Is that an ADR reg on the fuel lines?

Cheers

[Philm]

I thought the 300mm rule was for brake lines?


Phil

[boxhead]

If thats the case Phil I beter add a few more clamps.

[C0braed]

I think the 300mm rule applies to both brake and fuel lines

[stephen low]

Gregg

I'll be dropping into Marty's tomorrow so I'll try and measure my tank, but as I said I had Marty cut the top down to enable the pump to reach the base. The BA version has variable height like many of those pumps and sits in its own swirl chamber.

I just ditched the fuel sensing arm in favour of the vdo fittings I had bought.

So a V8 pump for a 5.4 l in a 5.0 l and no noise. Does run the two fuel lines however unlike the tricky GM version but finding space for these is far easier than space for a swirl pot and second pump.

Marty would have a spare pump in his shed if you had the time to get our there for a chat.

Cheers

[Ant]

I guess the principle is the same for EFI or carb as in my case, supplying adequate fuel at all times to the engine.

I have an alloy foam filled tank with two flexible pickups with large gauze filters, set in alloy cannisters with a slot for intake, sucking the fuel up is two little electric V8 holden pumps which can be bought at any Repco or BNT as here in NZ, these pumps send fuel to a Separate Tank which has a -12an return back to tank (this may need a restrictor to give a small amount of pressure) the tank has the Bypass return from Regulator, just below the return to tank. At the bottom of the tank is a -10an supply line to my Aeromotive 150gph street pump, that has a -8an line to the regulator etc, I believe this is adequate to supply the 675bhp engine.

Regarding hot fuel being returned from the Regulator I dont think that is an issue as it is being cooled by the flow from the tank and back to the tank, I think the trick is not to circulate the fuel to much but obviously a bit more than the carb needs.

Nice plumbing job Aussie Mike!

[gjkrv8]

Hi All,

I have been dabbling with fixing my fuel surge problems with a LP Lift pump and external Swirl pot as my Tank appears to be too shallow for a built-in arrangement.

My current setup is an external Bosch 044 with external reg.

I was looking at the back of my tank where the pickup outlet is and rightly so its right at he bottom of the tank.

If I put say a Carter Lift pump (which i have) level with the outlet the pump housing hangs down too low.

In the manual it says dont put the pump higher than 24 inches above the fuel tank.

To me this implies the LP pump can suck from a height of 24 inches?.

I have a convenient mount point for my LP pump about 100mm higher than the tank outlet?

Anyone done this before? i.e. had the LP pump higher than the tank outlet?

The only alternative I could see is an inline style LP pump that doesnt hang down etc.

Thanks

Rgds

Gregg

[*Cobber*]

The carters will lift 100mm no problems.

[Rebel1]

But remember, if you have a 200mm deep tank and the pump is 100mm above the tank then that's a lift of 300mm when the tank is low on fuel.

[gjkrv8]

Originally Posted by Rebel1

But remember, if you have a 200mm deep tank and the pump is 100mm above the tank then that's a lift of 300mm when the tank is low on fuel.

Thanks for the tip.

The tank of the 2008 CR is quite shallow as the boot floor is quite low. Only about 110mm at the edge of the tank where my outlet is so my max lift/suction height should be about 200mm.

The shallow tank actually limits you on being able to use in-tank combination pump/reg/swirl pot arrangements as they all seem to be taller than my tank.

I kinow I could do some fancy things to the tank, but at the moment I am try to work out a low-cost solution.

The Carter lift pump and Surge tank werent too expensive, although the plumbing adds up.

I might even conduct an experiment prior to mounting the pump with a rigged up can of fuel and check the suction of the pump. This would confirm it all.

Rgds

Gregg

[*Cobber*]

They will lift 2 - 3 ft I tried mine with a jerry can and it is fine. Just watch out for sparks when you hook up the pump when you are playing with fuel.

[gjkrv8]

Originally Posted by *Cobber*

They will lift 2 - 3 ft I tried mine with a jerry can and it is fine. Just watch out for sparks when you hook up the pump when you are playing with fuel.

Thanks Cobber you've saved me some time.

Yes I was thinking about the fuel/sparks not mixing. I was going to go to elaborate lengths to keep the two apart.

Dont need to now as I reckon I need the pump to suck less than 200mm.

Thanks again - Thats why I really like this forum, there is normally someone who's done it before.

Rgds

Gregg

[Rebel1]

Gregg, Your setup is the same as mine. Carter lift pump to the swirl tank I posted a pic of earlier. My carter has to lift 200mm at most.

It is a good proven system as it replicates a system we installed into a mates RMC a couple of years ago.

Up to that time he was suffering major surge problems and since the new setup hasn't had a problem.

[Gav]

I had alot of trouble with the VN style in tank pump not delivering, and have now turfed it and installed an intank pump from a 6 ltr LS2 car.
The pump is mounted on the same sender as the old VN unit but I have replaced the old 5/16" solid line with flexible 3/8". The 6ltr pump is rated at probably 50% greater flow than a LS1 pump and at greater pressure.
The fuel the flows up the the engine bay with 3/8" line through a filter and into the fuel rail.
From the rear driver side of the fuel rail, the fuel exits the rail and goes to a regulator.
The excess fuel then flows from the reg' to the return of the tank.
I have used this setup for a couple of events and have had no surge or starvation issues.
It is also quiet to boot!

[Tom Kirkham]

Here is a very nice design.

http://www.fortunecity.com/silversto.../swirlfaq.html