Baffling the Fuel Tank
Discussion
Have a look at the following blog. I think you'll find some pictures that provide hints about the mods that went into Robert Green's tank for racing. If memory serves, TurboHoses included a spring loaded flapper gate in the baffling, but there's probably a more technically correct name for it.
http://robertm400.blogspot.com/search?updated-min=...
Also search the Noble Rossion Forum for Urbalizer's posts about the tank mods he made. This is one thread, and you might find more.
http://www.nobleforums.com/showthread.php?p=76967#...
http://robertm400.blogspot.com/search?updated-min=...
Also search the Noble Rossion Forum for Urbalizer's posts about the tank mods he made. This is one thread, and you might find more.
http://www.nobleforums.com/showthread.php?p=76967#...
I am also just on with fitting a lifter pump and swirl pot, not that my baffled tank design did not do the job but i wanted added security with very low fuel levels, half of the problems with engines blowing is fuel related, so i am putting a bit extra into making sure fuel delivery is sorted.
I still stand by my previous tank design though, a tapered and baffled tank allows safe low fuel levels, where the same ammount would not cover the outlet on a normal tank design, people go to alot of trouble to reduce 20kg off the weight of their car, the tapered tank removes 20kg dead weight, you also get the same mileage because you can use all of the fuel. You woud need 25-30 litres to be safe with the stock tank and its just unuseable dead weight.
The tapered tank also allows the inlet to be at its very lowest point.
I do not have any internal pics and i also do not have my 3d modelling software on me at the moment but i will do a couple of rubbish sketches on paint so as to show the layout of the fuel system.
I still stand by my previous tank design though, a tapered and baffled tank allows safe low fuel levels, where the same ammount would not cover the outlet on a normal tank design, people go to alot of trouble to reduce 20kg off the weight of their car, the tapered tank removes 20kg dead weight, you also get the same mileage because you can use all of the fuel. You woud need 25-30 litres to be safe with the stock tank and its just unuseable dead weight.
The tapered tank also allows the inlet to be at its very lowest point.
I do not have any internal pics and i also do not have my 3d modelling software on me at the moment but i will do a couple of rubbish sketches on paint so as to show the layout of the fuel system.
The horizontal baffle is to stop fuel surging up the slope of the taper under heavy acceleration, all new baffles are solid plate which are stitch welded in place, gaps are left on vertical baffles to allow fuel to self levelhwne fuel level is low, these can be made full height, 3mm gap left on horizontal baffle to avoid fuel trap on top.
951 said:
Hi Chris,
I saw your other thread about what type of lifter pump to fit.
What did you go for in the end?
Regards
Graham
I spoke to my mechanic and he said he had something suitable... i would still like advice on a model of a suitable lifter pump though as i would prefer to put a new pump.I saw your other thread about what type of lifter pump to fit.
What did you go for in the end?
Regards
Graham
the lifter pumps I used were in tank ones so no use to you... I fitted 2 as whilst technically one can flow 600bhp Im never keen on being on the limit of the pumps technical max.
I used internal pumps because external ones can be noisy.... although i don't see why a stock 3r pump only delivering half a bar fuel to a swirl pot wouldnt be adequate?... need to check the flow to pressure curve of one.
I used internal pumps because external ones can be noisy.... although i don't see why a stock 3r pump only delivering half a bar fuel to a swirl pot wouldnt be adequate?... need to check the flow to pressure curve of one.
andygtt said:
you can run a regulator from the swirl pot back to the fuel tank... set it at 0.5bar!
044 hates sucking, would make a terrible lifter pump, stock is much better
yes i definately don't want to use a 044 as the lifter and i totally agree with having a small pressure in the swirl pot, i think the swirl pot already has a restriction on the return to achieve this but i may also look at some small fuel pressuer regulators.044 hates sucking, would make a terrible lifter pump, stock is much better
Great thread. Thanks for sharing. 
RO162, your drawings reminded me of a basic tank geometry question that I've been meaning to ask the experts since I read Urbalizer's thread last year but never got around to it. Obviously, we have a room full of experience in this thread.
Starting with the presumption that it's more critical to optimize fuel availability during max acceleration than during max deceleration, would it be more effective for the fuel to encounter the vertical wall during acceleration and the 45deg wall during deceleration? If I'm reading your diagram right, your and Urbalizer's designs are both oriented in the opposite way. Dying to understand.
If my reasoning has any merit, does it carry more weight if a swirl pot isn't included?
Thank you,
Bill
[Getting to know PistonHead's icons was fun. Appologies if I got carried away.]
RO162, your drawings reminded me of a basic tank geometry question that I've been meaning to ask the experts since I read Urbalizer's thread last year but never got around to it. Obviously, we have a room full of experience in this thread.
Starting with the presumption that it's more critical to optimize fuel availability during max acceleration than during max deceleration, would it be more effective for the fuel to encounter the vertical wall during acceleration and the 45deg wall during deceleration? If I'm reading your diagram right, your and Urbalizer's designs are both oriented in the opposite way. Dying to understand.
If my reasoning has any merit, does it carry more weight if a swirl pot isn't included?
Thank you,
Bill
[Getting to know PistonHead's icons was fun. Appologies if I got carried away.]
Edited by Bill NobleUS206 on Wednesday 21st March 05:19
Bill NobleUS206 said:
Great thread. Thanks for sharing.
RO162, your drawings reminded me of a basic tank geometry question that I've been meaning to ask the experts since I read Urbalizer's thread last year but never got around to it. Obviously, we have a room full of experience in this thread.
Starting with the presumption that it's more critical to optimize fuel availability during max acceleration than during max deceleration, would it be more effective for the fuel to encounter the vertical wall during acceleration and the 45deg wall during deceleration? If I'm reading your diagram right, your and Urbalizer's designs are both oriented in the opposite way. Dying to understand.
If my reasoning has any merit, does it carry more weight if a swirl pot isn't included?
Thank you,
Bill
[Getting to know PistonHead's icons was fun. Appologies if I got carried away.]
Bill, l think R0162 & Urbalzer are same person, no doubt Chris will confirm.RO162, your drawings reminded me of a basic tank geometry question that I've been meaning to ask the experts since I read Urbalizer's thread last year but never got around to it. Obviously, we have a room full of experience in this thread.
Starting with the presumption that it's more critical to optimize fuel availability during max acceleration than during max deceleration, would it be more effective for the fuel to encounter the vertical wall during acceleration and the 45deg wall during deceleration? If I'm reading your diagram right, your and Urbalizer's designs are both oriented in the opposite way. Dying to understand.
If my reasoning has any merit, does it carry more weight if a swirl pot isn't included?
Thank you,
Bill
[Getting to know PistonHead's icons was fun. Appologies if I got carried away.]
Edited by Bill NobleUS206 on Wednesday 21st March 05:19
R0162 said:
andygtt said:
you can run a regulator from the swirl pot back to the fuel tank... set it at 0.5bar!
044 hates sucking, would make a terrible lifter pump, stock is much better
yes i definately don't want to use a 044 as the lifter and i totally agree with having a small pressure in the swirl pot, i think the swirl pot already has a restriction on the return to achieve this but i may also look at some small fuel pressuer regulators.044 hates sucking, would make a terrible lifter pump, stock is much better
I put the swirl pot in the fuel tank, where are you planning to put yours, only place I could find was the side pod and I was very nervous of placing it in such an exposed area.... could fit quite a long and thin one there though that would have been effective.
Chris.... worth adding that if you are going to further modify the tank... consider putting the swirl pot in there as well, you can still have the pumps outside!
Also with a good swirl pot it means you dont need to worry quite as much about baffling the tank so you can extend it back to stock capacity... our pumps hate drawing air and when they do fuel pressure drops briefly causing major issues... lifter pumps dont mind sucking air as much and as long as your swirl pot is large enough there is no danger if they briefly suck air on cornering.
I run 2 lifters to ensure they can recover level in swirl pot quickly.. overkill I know.
I have litterally sucked my tank dry and still ran because there was 5litres of fuel in my swirl pot (I didnt have a petrol guage then and wondered why lifters had got noisy lol)... i regularly fill up over 55litres in my tank now and its still not fully empty!
Also with a good swirl pot it means you dont need to worry quite as much about baffling the tank so you can extend it back to stock capacity... our pumps hate drawing air and when they do fuel pressure drops briefly causing major issues... lifter pumps dont mind sucking air as much and as long as your swirl pot is large enough there is no danger if they briefly suck air on cornering.
I run 2 lifters to ensure they can recover level in swirl pot quickly.. overkill I know.
I have litterally sucked my tank dry and still ran because there was 5litres of fuel in my swirl pot (I didnt have a petrol guage then and wondered why lifters had got noisy lol)... i regularly fill up over 55litres in my tank now and its still not fully empty!
Hi Bill,
I am Urbalizer from the US forums, you are totally right about the 45deg taper, fuel would surge up the slope under heavy acceleration that is why i put the horizontal baffle which combats surge better than a vertical face when you are running at low levels, the factory fitted baffle also helps with this when there is more fuel in the tank, but thats more to reduce the fuel sloshing about rather than avoiding fuel starvation.
I am no expert on these things to be honest, all i did was just think about what happens to fuel moving about under acceleration and cornering and then took a best guess as how to combat it.
I really only looked at the design with regards to combatting fuel surge with low fuel levels, and the reason i do not put full height vertical baffles was purely due to the fuel sender, the baffles are probably not as high as shown on that schematic, my fuel tank shows empty when the arm on the sender hits the same level as the notch for the lifter pump, which leaves about 5 litres.
Although improved I could see that this system is still vulnerable on low fuel and i got fed up with my Boch 044 getting noisy every time the fuel was low.
I did some testing without swirl pot on 5 litres without any problems but not heavy testing on a race track,on the track i was still playing it safe with a minimum of 15 litres which takes the fuel approx to the top of the slope, this demonstrates my lack of total confidence, i mean who is willing to gamble an engine to properly test the system, so i thought to be fully confident, add a swirl pot, even if the lifter pump gulps air every now and then the swirl pot by design will always offer reliable fuel delivery to the master pump, to the point where i would put money on that you could run the tank dry due to the fuel return from the pressure regulator getting returned to the swirl pot. so in theory this system can run on 1 litre of fuel.
The swirl pots are only £50, and to get all the braided teflon coated hose to do the piping is about another £40 and then there is a lifter pump about another £50.
On the swirl pot, i am sure the top connector is the return to tank(this outlet feels quite restricted when trying to blow through it) and that the bottom one is the feed to the Bosch 044, but the feed from the lifter pump would you put it in the second from top on the side and the return from engine the one above or the other way round?..
The only thing that made me want to put the return from engine to the top side inlet is due to recirculation, i would prefer the warmed fuel that has passed through the Bosch044 to be the first to return to the main tank to help keep it cool, so i suppose this is more likely if connected at the highest point?
I am Urbalizer from the US forums, you are totally right about the 45deg taper, fuel would surge up the slope under heavy acceleration that is why i put the horizontal baffle which combats surge better than a vertical face when you are running at low levels, the factory fitted baffle also helps with this when there is more fuel in the tank, but thats more to reduce the fuel sloshing about rather than avoiding fuel starvation.
I am no expert on these things to be honest, all i did was just think about what happens to fuel moving about under acceleration and cornering and then took a best guess as how to combat it.
I really only looked at the design with regards to combatting fuel surge with low fuel levels, and the reason i do not put full height vertical baffles was purely due to the fuel sender, the baffles are probably not as high as shown on that schematic, my fuel tank shows empty when the arm on the sender hits the same level as the notch for the lifter pump, which leaves about 5 litres.
Although improved I could see that this system is still vulnerable on low fuel and i got fed up with my Boch 044 getting noisy every time the fuel was low.
I did some testing without swirl pot on 5 litres without any problems but not heavy testing on a race track,on the track i was still playing it safe with a minimum of 15 litres which takes the fuel approx to the top of the slope, this demonstrates my lack of total confidence, i mean who is willing to gamble an engine to properly test the system, so i thought to be fully confident, add a swirl pot, even if the lifter pump gulps air every now and then the swirl pot by design will always offer reliable fuel delivery to the master pump, to the point where i would put money on that you could run the tank dry due to the fuel return from the pressure regulator getting returned to the swirl pot. so in theory this system can run on 1 litre of fuel.
The swirl pots are only £50, and to get all the braided teflon coated hose to do the piping is about another £40 and then there is a lifter pump about another £50.
On the swirl pot, i am sure the top connector is the return to tank(this outlet feels quite restricted when trying to blow through it) and that the bottom one is the feed to the Bosch 044, but the feed from the lifter pump would you put it in the second from top on the side and the return from engine the one above or the other way round?..
The only thing that made me want to put the return from engine to the top side inlet is due to recirculation, i would prefer the warmed fuel that has passed through the Bosch044 to be the first to return to the main tank to help keep it cool, so i suppose this is more likely if connected at the highest point?
Edited by R0162 on Wednesday 21st March 09:20
Hi Chris,
As far as I am aware, this is the norm for the connections :
Or, with a flat bottom and the outlet to the 044(s) towards the bottom of the sidewall.
So, hot fuel returned from the fuel rail comes in at the top, fresh cool fuel from the tank via the low pressure/lifter pump enters at the bottom.
Regards
Graham
As far as I am aware, this is the norm for the connections :
Or, with a flat bottom and the outlet to the 044(s) towards the bottom of the sidewall.
So, hot fuel returned from the fuel rail comes in at the top, fresh cool fuel from the tank via the low pressure/lifter pump enters at the bottom.
Regards
Graham
Edited by 951 on Wednesday 21st March 10:01
951 said:
Hi Chris,
As far as I am aware, this is the norm :
Regards
Graham
Interesting. I'd have thought that the purpose of the swirling effect is to remove aerated fuel from the high pressure pump, therefore you'd want the lift pump to be feeding as far away as possible from the outlet ie. top side connection. As far as I am aware, this is the norm :
Regards
Graham
Chris where are you planning on putting filter/s? Just 1 before the lift pump as per your diagram? Nothing past the 044?
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