Question about fuel pumps
Discussion
Can someone explain the idea of fitting 2 fuel pumps, why not 1?
I think there are a few of you out there that have done this, what pumps did you go for and did you need a fuel swirl pot?
If you do run 1 pump where is the best place to fit it I'm guess having 1 pump will be bigger in size.
I think there are a few of you out there that have done this, what pumps did you go for and did you need a fuel swirl pot?
If you do run 1 pump where is the best place to fit it I'm guess having 1 pump will be bigger in size.
I did not know the make, never heard of them to be honist.
As long as they don't tick like a fasit red top.......
But why 2, do you have both pumps running at the same time or do you just have one on and when the tank is empty switch to pump 2?
Why not run one stightly bigger one to do the job of 2?
As long as they don't tick like a fasit red top.......
But why 2, do you have both pumps running at the same time or do you just have one on and when the tank is empty switch to pump 2?
Why not run one stightly bigger one to do the job of 2?
Do you know any more details of the twin pump setup? I think the typical approach is to have a 'lifter' pump that feeds a swirl pot, and a high pressure pump fed from this that supplies the engine. Is that the sort of setup you're thinking about?
With this setup you can ensure that the high pressure pump doesn't suffer from fuel surge and doesn't have any suction on the inlet - high pressure pumps don't tend to like that.
I guess the other possible setup is with two high pressure pumps in parallel, perhaps for redundancy?
With this setup you can ensure that the high pressure pump doesn't suffer from fuel surge and doesn't have any suction on the inlet - high pressure pumps don't tend to like that.
I guess the other possible setup is with two high pressure pumps in parallel, perhaps for redundancy?
On a carb setup :
The pumps individually taking fuel from one tank or the other. The switch (manually operated) selects one tank/pump or the other and changes over to the correct fuel level sensor in the appropriate tank.
Each pump feeds through a one way valve to a tee connector and the outlet of this tee goes to the carbs.
I like the idea of taking fuel like this as a failure of a pump leaves you with the other side and tank.
The Carter (Federal Mogul) pumps are quite audible when the engine is not running even though they are mounted on rubber bushes!!
The efi setup needs to be quite different with the low pressure (lifter) pumps feeding a swirl pot which in turn feeds the high pressure pump.
The pumps individually taking fuel from one tank or the other. The switch (manually operated) selects one tank/pump or the other and changes over to the correct fuel level sensor in the appropriate tank.
Each pump feeds through a one way valve to a tee connector and the outlet of this tee goes to the carbs.
I like the idea of taking fuel like this as a failure of a pump leaves you with the other side and tank.
The Carter (Federal Mogul) pumps are quite audible when the engine is not running even though they are mounted on rubber bushes!!
The efi setup needs to be quite different with the low pressure (lifter) pumps feeding a swirl pot which in turn feeds the high pressure pump.
basically the two tanks are separate, so you switch one pump off and the other on to use each tanks fuel.
So you only have one pump running.
Many have joined the tanks together so it effectivelly becomes one tank and then run a single powerful pump that takes from both at the same time. I did this with mine for two reasons, so that I didn't have to fill each tank separatelly and because the outputs from each tank are only -6.
So you only have one pump running.
Many have joined the tanks together so it effectivelly becomes one tank and then run a single powerful pump that takes from both at the same time. I did this with mine for two reasons, so that I didn't have to fill each tank separatelly and because the outputs from each tank are only -6.
andygtt said:
basically the two tanks are separate, so you switch one pump off and the other on to use each tanks fuel.
So you only have one pump running.
Many have joined the tanks together so it effectivelly becomes one tank and then run a single powerful pump that takes from both at the same time. I did this with mine for two reasons, so that I didn't have to fill each tank separatelly and because the outputs from each tank are only -6.
I'm gonna run one pump too.... but had the factory change to -12 fittings in the tank.
lord james said:
I did not know the make, never heard of them to be honist.
As long as they don't tick like a fasit red top.......
But why 2, do you have both pumps running at the same time or do you just have one on and when the tank is empty switch to pump 2?
Why not run one stightly bigger one to do the job of 2?
I have two Facet red tops that tick very loudly and an EFI pump that hisses loudly, but I can't hear any of them over the sound of the V8 just behind my ears!
-12 seems rather large.
So how will that work come of of each tank in -12 into the pump, then into a -6 to the engine?
"I have two Facet red tops that tick very loudly and an EFI pump that hisses loudly, but I can't hear any of them over the sound of the V8 just behind my ears!"
See I'm going to try my best to sound proof the cab, my last few cars have been so full on my hearing going from Gearbox and engine noise.
So how will that work come of of each tank in -12 into the pump, then into a -6 to the engine?
"I have two Facet red tops that tick very loudly and an EFI pump that hisses loudly, but I can't hear any of them over the sound of the V8 just behind my ears!"
See I'm going to try my best to sound proof the cab, my last few cars have been so full on my hearing going from Gearbox and engine noise.
I'm at that stage now. I didn't want the tank changeover switch on the dash plus having to remember to switch them over to balance them up or fill one tank at a time etc. So I have done the following to my tanks;
I am using the top link pipe which is -6
I have linked the tanks about three inches from the bottom with -12
I'm drawing fuel from both tanks via -6 into a Y piece -6 to -8 to a Holley Blue top pump this is feeding a billet filter -8 to the regulator then into the Demon Carb fuel pressure gauge -6 into the carb.
The -12 link pipe is high enough not to be affected by stavation
Yes I have only one pump, but on all my cars (and yours) I've only ever had one pump, if it fails then I guess I'm unlucky.
I can fill up on either side and the -12 link will balance the tanks.
Oh yeah and it's cost me well under half of the twin pump set up!!
Graham
I am using the top link pipe which is -6
I have linked the tanks about three inches from the bottom with -12
I'm drawing fuel from both tanks via -6 into a Y piece -6 to -8 to a Holley Blue top pump this is feeding a billet filter -8 to the regulator then into the Demon Carb fuel pressure gauge -6 into the carb.
The -12 link pipe is high enough not to be affected by stavation
Yes I have only one pump, but on all my cars (and yours) I've only ever had one pump, if it fails then I guess I'm unlucky.
I can fill up on either side and the -12 link will balance the tanks.
Oh yeah and it's cost me well under half of the twin pump set up!!
Graham
Graham-P said:
I'm at that stage now. I didn't want the tank changeover switch on the dash plus having to remember to switch them over to balance them up or fill one tank at a time etc. So I have done the following to my tanks;
I am using the top link pipe which is -6
I have linked the tanks about three inches from the bottom with -12
I'm drawing fuel from both tanks via -6 into a Y piece -6 to -8 to a Holley Blue top pump this is feeding a billet filter -8 to the regulator then into the Demon Carb fuel pressure gauge -6 into the carb.
The -12 link pipe is high enough not to be affected by stavation
Yes I have only one pump, but on all my cars (and yours) I've only ever had one pump, if it fails then I guess I'm unlucky.
I can fill up on either side and the -12 link will balance the tanks.
Oh yeah and it's cost me well under half of the twin pump set up!!
Graham
good to hear! well done, I don't like the twin pumps and 2x fill ups eigther... glad to hear it can be done and its not that expensive
one worry les when I buy a Ultima GTR in the future! GTRene
Oh no, you guys are missing something on the twin tank fill up. I love it.
I drive into the gas/petrol station and everyone else stops and stares.
Cars pull in from the street, just to ask me about the car and take photos.
I finish filling up one tank...
Then drive all of 30 feet doing a 180 degree turn to turn the car around to present the other side of the car to the pump. Filling up the other side of the car causes a hush through the crowd.
Trust me - get both tanks, and get both fuel pumps. For high performance endurance racing, run a drain link between the tanks (they come with this extra outlet) so that you can continue to race if one fuel pump burns out, but drain from both tanks.
I drive into the gas/petrol station and everyone else stops and stares.
Cars pull in from the street, just to ask me about the car and take photos.
I finish filling up one tank...
Then drive all of 30 feet doing a 180 degree turn to turn the car around to present the other side of the car to the pump. Filling up the other side of the car causes a hush through the crowd.
Trust me - get both tanks, and get both fuel pumps. For high performance endurance racing, run a drain link between the tanks (they come with this extra outlet) so that you can continue to race if one fuel pump burns out, but drain from both tanks.
Craig, see there is a cultural difference between us Brits and you Americans, or it could just be me! The first time I filled up was a bit like you and I felt a bit of a show-off (read plonker) and soon learnt to park close enough for the pump nozzle to reach (just sometimes) both sides of the car so it could be done with the minimum of fuss. The reaction of the British to our cars seems a little less, adults ask questions with an understated (read stiff upper lip) attitude trying not to show too much interest (although you always get some hanging out of van windows taking pictures on their phones). Kids show a little more but secretly would probably like to nick it or do some serious damage. Me, I try to disguise the fact that I have just put £70 worth of petrol ($120 of gas) in it, on a very regular basis.
eliot said:
When was the last time anyone ever had a fuel pump fail in *any* car they owned? - I have never had one fail. I think one failed in my dads Moris Minor about thirty years ago - if that counts?
I had both of my red top pumps fail on a trip to the Donington show a couple of years ago! One failed on the way up, but the other one got me there, then the other one failed on the way home. Every ten miles or so I had to dive for the hard shoulder as the engine died, jump out and give the pump a good thump which made it spring back into life (this trick worked well with the SU pumps fitted to early minis and Morris Minors!) To this day I do not know what the problem was, I just fitted two new pumps because I was due at a Goodwood track day the following day.
I'll get my coat.. I had what I thought was an intermittent pump failure (single Holley Blue). It would cut out with no warning and then come back on after a few minutes. Replaced pump, same thing. After reading a thread on here regarding the lack of relay on fuel pump circuit, I duly fitted relay and no problem since. I am guessing that my immobiliser circuit breaker did not like having to deal with the amps required to run pump so would cr@p out from time to time.
There is an added benefit to twin tanks and fuel pumps. Like me, you could roar out of the petrol station with everyone watching, only to have the engine die at the end of the ramp because your knee accidently placed the pump selector to "middle" postion. To make matters worse, you sit there for a few minutes thinking the worst (and so do "they".
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