Major Stare
|
 posted on 10/3/07 at 08:24 AM |
|
|
EFI without a fuel swirl pot.... possible ?
Fitted the MegaSquirt and all fuel plumbing but the boot area looks like a spagetti junction...Swirl pot, two pumps, two filters, pipework.
Im not happy with this so has anyone run an EFI car with just an HP pump and filter but without a swirl pot???
I understand HP pumps dont "suck" very well, so it will be mounted below the tank outlet.
Anyone ??
Jon "FISH"
|
|
|
|
|
graememk
|
| posted on 10/3/07 at 08:26 AM |
|
|
i'm using the donors in tank fuel pump (nissan) and piped it straight to the injectors, works ok for me........ so far
|
|
|
martyn_16v
|
| posted on 10/3/07 at 08:31 AM |
|
|
mk3 golf gti's also have a single in tank pump
|
|
|
RazMan
|
| posted on 10/3/07 at 09:03 AM |
|
|
I used a Landrover internal pump complete with sender unit - it fits inside the tank (immersed) It saves a heck of a lot of space (and plumbing) and
no messing around with fuel gauge sender units either. Works a treat. 
[Edited on 10-3-07 by RazMan]
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
|
|
|
Humbug
|
| posted on 10/3/07 at 09:58 AM |
|
|
I have had no fuel problems with my K-series - the outlet is right at the bottom of the tank then I've got a filter and a pump then pipe
straight to the engine.
|
|
|
blakep82
|
| posted on 10/3/07 at 10:41 AM |
|
|
I don't think the swirlpot would work, because it would have air in it (i assume, i'm not too good on fuel systems) and therefore cause
problems with the pressure
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
|
|
|
stevebubs
|
| posted on 10/3/07 at 11:06 AM |
|
|
So long as you can ensure the EFI pump is fully submerged all of the time then you won't have issues.
Many of these pumps won't run dry for more than 3-4 seconds which is why swirl pots are recommended.
|
|
|
nitram38
|
| posted on 10/3/07 at 11:27 AM |
|
|
I am using a bosch bmw injection pump that sits just below the tank. The pump is fed from a plastic oval racer tank (rally design). The outlet is at
the top of the tank with an internal pipe that reaches the bottom.
In other words my pump draws fuel upwards as well as through to the engine.
Not ideal, but saves any leaks from tank unions.
Once you prime the pump the first time, the fuel stays in the pipe.
Never had a problem. Fuel pumps generally supply more fuel than you need and that is why mine has a return pipe to the tank.
A little tip though, ensure your tank has a two way breather valve or the tank will pressurize because of air being drawn in to replace the pumped
fuel on a one way valve.
This is because the fuel returning to the tank now cannot force any air out of the one way valve.
I made this mistake and the tank pressurized and then fooked the pump!
[Edited on 10/3/2007 by nitram38]
|
|
|
ibakes
|
| posted on 10/3/07 at 12:02 PM |
|
|
I was on the phone to southern carbs the other day who reccomended having a feed from both sides of the tank, that way you should get a feed which
ever corner you go around... not sure about air tho?
|
|
|
britishtrident
|
| posted on 10/3/07 at 02:23 PM |
|
|
You can fit the pump, inside the tank or you can go a stage further and fit the pump and a combined filter & pressure regulator inside the tank,
many recent models do this to avoid reduce fire risk in the event of major accident as it removes the need for a return line.
The Rover 600/Honda has neat inside the tank fuel pump assembly that flange mounts and is roughly the correct height for a Locost tank. It is also
very easy to remove from the donor as it is accesed via a hatch from the rear seat area.
|
|
|
Major Stare
|
| posted on 10/3/07 at 11:24 PM |
|
|
Cheers guys.
The fuel tank is a Westfield item with the fuel outlet on the side of the tank and at the bottom.
The fuel filter is mounted externally as is the Jaguar pump, it is not mounted internally !!
Basically, dont run less than 1/4 of a tank ?
Jon "FISH"
|
|
|
MkIndy7
|
| posted on 11/3/07 at 12:50 PM |
|
|
quote:
Originally posted by ibakes
I was on the phone to southern carbs the other day who reccomended having a feed from both sides of the tank, that way you should get a feed which
ever corner you go around... not sure about air tho?
That sounded a clever idea at first.... But wouldn't the fuel pump just suck on the side that had run short of fuel as it would be easier to
suck the air than the fuel?
|
|
|
stevebubs
|
| posted on 11/3/07 at 12:57 PM |
|
|
I think the theory is that gravity will pull the "heavier" petrol into the feed pipe...means the pipes must go down for a period (i.e.
don't route upwards straight from the tank)
|
|
|
MkIndy7
|
| posted on 11/3/07 at 02:38 PM |
|
|
Hmm maybe then...
We were thinking of using quite a large fitting screwed into the tank... say like 1-2" and then reducing down to the 10mm or whatever fuel pump
inlet.. like a mini resevoir thats lower than the rest on the tank.
|
|
|
britishtrident
|
| posted on 11/3/07 at 07:13 PM |
|
|
Two inlets it will be worse than a single central suction, unless two lp lift pumps & a swirl pot are used.
As for mounting an especially low inlet of some kind, the problem is it will just act as a collector for water and sediment. Water will get into the
tank via condensation even if the fuel is 100% dry to start with.
Degassing the tank and fitting a flange mounted in tank HP pump is probably the easiest neatest low cost option.
|
|
|
britishtrident
|
| posted on 11/3/07 at 07:32 PM |
|
|
quote:
Originally posted by RazMan
I used a Landrover internal pump complete with sender unit - it fits inside the tank (immersed) It saves a heck of a lot of space (and plumbing) and
no messing around with fuel gauge sender units either. Works a treat.
[Edited on 10-3-07 by RazMan]
You want to see the system Rover used on the petrol 75. all BMW VDO parts but crazy stuff. The tank is a saddle tank to allow for the RWD V8
propshaft.
The pump and one level sender are in the right side of the tank, this pumps fuel over to the regulator and filter which are in the left section
(also fitted with another level sender), fuel exits from here to the engine feed line. The return fuel from the regulator goes back to the right side
pump swirl pot via an edductor which sucks some additional fuel from the left side of the tank over to the right. All the extra plumbing and wiring
is internal to the tank.
Works fine except the fuel filter is fitted with a bayonet fitting that has a nasty habit of undoing itself after 3 or 4 years -- result no fuel out
put the fuel pump just pumps fuel from the right of the tank to the left. Result a non starting Rover which can cause an a amazing amount of head
scratching unless you have encountered one before.
|
|
|
joscorstjens
|
| posted on 12/3/07 at 11:29 PM |
|
|
could the solution of the attached drawing bring a solution?
 
Rescued attachment fuelaccum.gif
|
|
|
BKLOCO
|
| posted on 13/3/07 at 07:39 PM |
|
|
For what it's worth my solution to this problem was to build a "swirl pot" into the tank.
I made a cup shaped pot approx 200mm high and 100mm dia.
The 12mm outlet to the HP pump was taken from the bottom of this pot. There were two 25mm holes cut in the sides half way up the pot which was then
welded into the tank with the 25mm holes 5mm above the bottom of the tank base.
The pot was filled with tank foam and a strainer fitted to the outlet.
The return pipe from the fuel rail was welded into the top of the tank so that it enters the top of the pot. This gives me a small reservoir (100mm
deep X 100mm dia) that is being re-plenished with returning fuel should the fuel in the tank surge on corners.
This has worked without any problems both on the road and some "spirited" driving on a disused airfield.
Hope you can work out what I am talking about from the above description.
Experience is what you get when you don't get what you want!!! 
|
|
|
Russiow
|
| posted on 13/3/07 at 10:59 PM |
|
|
ATL do internal collectors which sit in the bottom of the tank.
They have 3 trap doors which only let fuel into the centre so when you corner hard the fuel can't get out??
Also they do them with internal fuel pump mounts.
Have a look on there website..
http://www.atlinc.com/US/racing.html
Russ
|
|
|
.jpg)
