Fuel Pump Quandry

[Al Milton]

Hi All,

 

I am ditching the standard RH kit supplied Ford (Fiesta / Escort??) tank on my SuperSpec (04 - Rover engine) and replacing with the RH 30ltr tank, (to make better use of the boot space so that the misses can pack her hair dryer, make up, sink etc ). I am boxing the boot area with 9mm exterior ply, covered with fibre glass resin for waterproofing etc.

 

Reading previous posts, the preferred route appears to be tank / low pressure (LP) pump / swirl pot / high pressure (HP) pump for fuel injection. Looking through various suppliers' catalogues, the choice of pumps is various. The engine requires fuel at 3 bar, so the HP pump seems a no brainer (Facet type interrupter pump), but the selection for the LP pump seems a little confusing, or am I being a bit daft and seeing too much in the choices?

 

The RH tank does not have a swirl pot, so I have a cheapie from e-bay, (nice alloy one). The options open appear to be:

 

Stick with the route described above

Mod the tank to accept a Webcon all in one swirl pot / sender / pump assembly (anyone had experience of this unit?)

Get another tank (OBP tank with integral swirl pot). 11.5 gals has pot, but does it fit??

 

Any help or advice on recommending a suitable LP pump or route from above appreciated.

 

Cheers

Al

[Bob Tucker]

Hi Al,

the Facet won't provide the 3 bar....45 psi...needed for the fuel injection system.

 

FACET competition redtop pump

looks like 6.5 psi at most...

 

I think most peeps stick with the OEM high pressure pump & supply the low pressure side with a Facet.

Even the cube block type can supply enough volume of fuel. RD seems to be cheapest.

 

HTH Bob

[stevedohc2b]

I would mod the tank and take off from bottom with a swirl pot built in to the bottom of the tank then a HP in line pump less to go wrong try to use gravity and keep simple.

 

Or if you have the large ford tank you have a hp pump build that in to a larger swirl pot fed from bottom of main tank by gravity.Job done. Sell swirl pot back on e bay.

 

Stephen

[Guest rob west]

Hi, i fabricated a new tank for my super spec. I cut out the swirl pot from the sierra tank supplied along with pump and fuel level sender. This worked well but the RH pump kept falling off inside the tank, so i fitted an external pump and all is well. It gives a good boot space this mod, enough for the hair dryer and the straighteners! Regards Rob.

[steve in stockport]

A facet solid state pump, either fast road or comp spec will be enough to supply the swirl pot at low pressure, for the high pressure pump look for a vauxhall cavalier, calibra or astra pump, these are external mounted and will lift up to 300mm so giving you a bit of scope about where you mount it.

 

Another popular one was the VW golf pump with built in accummulater/swirl pot.

 

Steve

[Al Milton]

Thanks for the ideas guys.

 

I had thought initially about transfering the Ford swirl pot etc from the original tank Rob, but the plastic innards of the pot within the tank put me off this.

 

Steve / Bob, Facet pumps seem by far a most popular choice. If I were to mod the bottom of the tank Stephen, would this simply be welding a stainless 'pot' with suitably sized fuel outlet to the hp pump? Would there have to be any special profile to this pot (square / circular)? Any idea how deep this would have to be?

 

As always, comments appreciated. Thanks for the help.

 

Cheers

Al

[stevedohc2b]

A simple yes have a look at a westfield tank and it looks like a small reservoir on the bottom of tank.

 

or do as Darren Fasey has use pluming fittings ie a tank fitting and copper pipe to a large swirl tank with an in tank HP pump this as mounted behind diff.

 

Pound land has some nice stainless steal food bowls that i think would only need a lid welding that would be ideal for this tank make the lid larger with a couple of folds in to give a mounting flange.

 

cheap as chips.

 

Stephen

[Guest salty_monk]

Be aware that there is "stainless" & there is "stainless" not all grades are the same

 

The Golf GTI 8V pump is well documented. It's external & comes as a complete assy with filter & "accumulator" (read swirl pot). It's good for about 180bhp allegedly.

 

Dan

[Al Milton]

Thanks for the thoughts and comments, plenty of thinking been running through the head.

 

Have drawn up a simple tank mod, can anyone see any problems with this? (see attached - sorry for the naff drawing). Then just pipe direct to the hp pump via a filter set. I like simple, thanks Stephen.

 

Can't vouch for the grade of stainless the tank is made from, but the tank mod will be in either 304 or 316 ss, whatever sheet is lying around in the engineering welding workshop, unless some major faults are identified on the drawing. I will earth out the tank separately as it won't be in direct contact with the chassis.

 

As always, thanks for the advice.

 

Al

Tank_Mod006.pdf

[Guest chris brown]

Looks good to me but why have such a large hole from tank into swirl pot? I would think 15 or 20mm would be more than adequate. Also take your feed (from pot to pump) from the front centre rather than the side

[Al Milton]

Thanks for the comments Chris, did have some reservations about the size of hole, probably will step this down to 50mm.

 

Always good to get feedback.

 

Cheers

Al

[Guest salty_monk]

I would go for an inch not two if you want to stay in English measurements (or the 3/4 that Chris suggested).

 

Less chance of fuel splashing back out that way I would think.... you're basically trying to stop it moving so that the pump has constant feed even when the tanks is low....

 

[Al Milton]

Well, here is Version 2 of the drawing, updated after comments from Chris and Dan, cheers Guys

 

Hopefully will be off to the fabrication shop this morning if the welder is in!!

 

Thanks for all the feedback, will post a piccy or two when completed.

 

Cheers

Al

Tank_Scan_ver.20001.pdf

[Guest timswait]

Agree with all the comments above, why add complexity with an extra lift pump and external swirl pot when you can get gravity to do the work for you?

I've done very much what you describe, I used the bottom of a fire extinguisher welded to the bottom of the tank as my swirl pot, it's domed too, which helps keep the pick up in the fuel. Also agree there's no point in having such a big 'ole between the tank and the pot. You want it to act like a baffle, so I drilled 5x 10 mm holes into the bottom of the tank and then welded the pot over them. Think about the aim of the pot - to keep the pick up fully immersed in fuel even when the tank's nearly empty and the car's cornering hard (think the tank is tilting). It works very well on my car, I've never had any fuel starvation even when the tank only has about a litre left. There's photos on a post I put on the forum at the time, probably about a year ago. For my HP pump I used one from a 2.0EFi SOHC Sierra, from looking at it I'd say it's probably identical to the Cavalier/Astra one.

[Al Milton]

Well, got fuel tank back from the welder this afternoon, pleased with the result. There is a bit of distortion due to heat from the welding, (he didn't have any steel as thin as the tank steel, so had to use some 1.5mm 304 stainless), but no leaks. Filled with water and hey ho, all was dry.

 

Pics as promised for info, thanks everyone for your help and advice, always appreciated.

 

Just got to fit it now........

 

Cheers

Al