Fuel Tank design
Discussion
Some will have noticed that I am having fun designing my fuel system for my Noble... The existing tank is terrible design with no baffles and there is very limited space for additional swirl pots and pumps etc.... its recomended you NEVER run the car below quarter of a tank on track due to the poor design (an actual offical Noble release letter), which leaves around 25litres of unused fuel in the tank.
So I am addressing this issue by making a new replacement tank... its a tall squarish tank with the filler at the top.
My idea is to make the whole top removable so I can fit the A1000 pump in tank to quieten it down and also internal baffle the tank and have foam in the lower quarter.
But I thought Id ask on here if anyone has any recomendations on its design/spec prior to me having it made?
cheers
andy
So I am addressing this issue by making a new replacement tank... its a tall squarish tank with the filler at the top.
My idea is to make the whole top removable so I can fit the A1000 pump in tank to quieten it down and also internal baffle the tank and have foam in the lower quarter.
But I thought Id ask on here if anyone has any recomendations on its design/spec prior to me having it made?
cheers
andy
Consider the filler arrangement and how the displaced air is returned to the filler neck! (it's a real pain having a tank that can only be filled at about 1 litre every 5 days ;-). This air return pipe work needs to be a decent diameter and ideally return to the filler neck in such a fashion as to not blow small droplets of fuel back out the filler! (most filler necks have a "tube within a tube" to prevent this).
Either have an internal swirl pot with flappy doors that the pump sits in, or try to have a small "sump" that sticks out below the main tank by and inch or so, to guarentee total fuel usage.
Ensure the fuel return line is pumping fuel back into the swirl pot, not the main tank volume.
Consider the fuel level gauge, if you have a level monitoring system that can be calibrated to account for fun shaped tanks thats great, but if not, try to keep the tanks area constant with height.
If you are going to fill the tank with anti-slosh foam, you need a reasonable sized opening to get this foam into the tank. (if you use a lever arm floating level gauge system, check for clearance to your foam filling)
Consider having the filler non return valve mounted on the tank, and use a proper "ball type" or nicely sealed "flap type" valve for safety reaons (often this is built into the tank filler pipe work where it sticks into the tank (also acts as antisyphon valve) so can be got from a scrappy for low cost)
Are you going to maintain the carbon canister / vacuum purge system? (does a noble even have this??)
Consider the strength of the mounting, a full tank can weigh 50kg, so needs to be firmly restrained in an accident situation
Consider the proximity of hot components like exhausts etc, and the proximity and potential movement in chassis hard points during a crash (i assume std car doesn't have a plastic tank!)
Either have an internal swirl pot with flappy doors that the pump sits in, or try to have a small "sump" that sticks out below the main tank by and inch or so, to guarentee total fuel usage.
Ensure the fuel return line is pumping fuel back into the swirl pot, not the main tank volume.
Consider the fuel level gauge, if you have a level monitoring system that can be calibrated to account for fun shaped tanks thats great, but if not, try to keep the tanks area constant with height.
If you are going to fill the tank with anti-slosh foam, you need a reasonable sized opening to get this foam into the tank. (if you use a lever arm floating level gauge system, check for clearance to your foam filling)
Consider having the filler non return valve mounted on the tank, and use a proper "ball type" or nicely sealed "flap type" valve for safety reaons (often this is built into the tank filler pipe work where it sticks into the tank (also acts as antisyphon valve) so can be got from a scrappy for low cost)
Are you going to maintain the carbon canister / vacuum purge system? (does a noble even have this??)
Consider the strength of the mounting, a full tank can weigh 50kg, so needs to be firmly restrained in an accident situation
Consider the proximity of hot components like exhausts etc, and the proximity and potential movement in chassis hard points during a crash (i assume std car doesn't have a plastic tank!)
Im cosidering the design around the pump... Im thinking that the pump will be quieter in tank but if its marginal I might not bother as it adds complexity, amy views on this?
My plan is to make the tank the same size as now (its alloy as std) and use the same filler arangement just relocated so no real change here... it doesnt have any carbon filtering just vents via the cap as std lol
the sender is a pipe style rather than float so will work with the foam and the top will have a 200mm square hole for access... I was thinking of having a 100mm swirl pot internally around 500m tall with small slots to equalise fuel but not allow it to move out much, pump will not sit in this swirl pot but lowest point will outlet to the filter and into pump.
In truth its the internal swirl pot design and location of the pump that im dwelling most on. do i bother putting the pump in tank or just design the tank well internally (sump foam etc) and have an outlet to the filter and pump...
My plan is to make the tank the same size as now (its alloy as std) and use the same filler arangement just relocated so no real change here... it doesnt have any carbon filtering just vents via the cap as std lol
the sender is a pipe style rather than float so will work with the foam and the top will have a 200mm square hole for access... I was thinking of having a 100mm swirl pot internally around 500m tall with small slots to equalise fuel but not allow it to move out much, pump will not sit in this swirl pot but lowest point will outlet to the filter and into pump.
In truth its the internal swirl pot design and location of the pump that im dwelling most on. do i bother putting the pump in tank or just design the tank well internally (sump foam etc) and have an outlet to the filter and pump...
Internal is way too much work. But a mini sump would be worth the effort.
Plan on MT coming good with the fuel pump controller which will eliminate the noise where it is the most nuisance.
An external swirl pot will be easiest to do if you can find space. Perhaps forfeit some of the tank size and put it on the end.
Are you not supposed to fill the whole tank with foam to get the benefit of explosion resistance?
Steve
Plan on MT coming good with the fuel pump controller which will eliminate the noise where it is the most nuisance.
An external swirl pot will be easiest to do if you can find space. Perhaps forfeit some of the tank size and put it on the end.
Are you not supposed to fill the whole tank with foam to get the benefit of explosion resistance?
Steve
Your definatelly understanding were Im coming from Steve, Im really stuggling to justfiy putting the pump in the tank but I want to make sure its the right choice lol
The issue I have with a swirl pot is even if its in tank I cant see an effective way to have one without a lifter pump.
The issue I have with a swirl pot is even if its in tank I cant see an effective way to have one without a lifter pump.
Anyone making a tank will have no issue filling with foam, or adding an internal collector around the pump.
But If possible, I'd still go with the pump lowered down into a sump, perhaps as well as a collector built around the sump.
IMO a sump is the ultimate collector...effectively a swirl tank all in one.
Even my low rectangular tank hasnt had any fuel surge issues and it has an internal collector. I had asked for and wanted a sump....but for some reason the fabricator wouldnt do it !!!
Should have went elsewhere, but he did a good job in the end anyway.
I never let it get much below 1/4 tank though. No matter how good a collector is, if the tank is only say 12" tall, and the collector may be 3" tall. If there is only 2" of fuel in the tank, the collector can never be full.
A sump will always be full !!
But If possible, I'd still go with the pump lowered down into a sump, perhaps as well as a collector built around the sump.
IMO a sump is the ultimate collector...effectively a swirl tank all in one.
Even my low rectangular tank hasnt had any fuel surge issues and it has an internal collector. I had asked for and wanted a sump....but for some reason the fabricator wouldnt do it !!!
Should have went elsewhere, but he did a good job in the end anyway.
I never let it get much below 1/4 tank though. No matter how good a collector is, if the tank is only say 12" tall, and the collector may be 3" tall. If there is only 2" of fuel in the tank, the collector can never be full.
A sump will always be full !!
As Stevie says a collector or sump will only contain fuel to the depth left in the tank so unless you can make the sump quite deep you still have the risk of starvation.
The swirl pot does not have to be round like the tank on a dry sump oil system. You could create your swirl/surge pot just by walling off one corner of the tank leaving a triangular pot but don't take it right to the top of the tank. Use a lift pump to continuously fill it until it overflows back into the main tank.
Steve
The swirl pot does not have to be round like the tank on a dry sump oil system. You could create your swirl/surge pot just by walling off one corner of the tank leaving a triangular pot but don't take it right to the top of the tank. Use a lift pump to continuously fill it until it overflows back into the main tank.
Steve
Positioning of the internal "catchment device" can be important. You are most likely to need full fuel flow under accel, so you want the swirl pot to be at the back of the tank (where the fuel goes when you accelerate). You can easily buy or fabricate a "ramp type" catcher using trap doors (http://www.ultrarev.com/ks145.html). using the ramps the fuel sloshes up the ramp, gaining some height off the bottom of the tank, rushes through the trap door, and then falls into a "sump" (which due to the ramps doesn't have to stick out the bottom of the tank). The ramps tend to have vertical strakes heading to each corner of the tankt to steer the fuel towards the catcher.
http://www.ultrarev.com/itc300.html
http://www.ultrarev.com/itc300.html
Doesnt matter whether round, square, whatever. But a sump used in conjunction with an internal collector will be best.
Even if it is only 2-3" deep, it will still be an improvement over a flat bottomed tank.
or if the actual tank design is small or vertical enough at the bottom, maybe it simply isnt needed at all. Good baffling and foam may be sufficient
Even if it is only 2-3" deep, it will still be an improvement over a flat bottomed tank.
or if the actual tank design is small or vertical enough at the bottom, maybe it simply isnt needed at all. Good baffling and foam may be sufficient
Biggest problem I have is the size of the pump and fuel filter..... combined they practically fill the bottom of my tank making a collector or sump built around them pretty ineffective (500mm long)... even if I split them the pump alone is over 300mm
Tank is 350mm long, 500mm wide and 550mm high... so pretty close to an upright box.
If the pump is in tank its going to be hard to be hard to reduce vibration due to the plumbing so might actually make it noisier?
Im thinking sump of some kind and pump/ filter external but under the tank next to the sump... loose a little size in the tank but seeing as I cant use this fuel now its not going to matter one bit i guess.
Tank is 350mm long, 500mm wide and 550mm high... so pretty close to an upright box.
If the pump is in tank its going to be hard to be hard to reduce vibration due to the plumbing so might actually make it noisier?
Im thinking sump of some kind and pump/ filter external but under the tank next to the sump... loose a little size in the tank but seeing as I cant use this fuel now its not going to matter one bit i guess.
Edited by andygtt on Tuesday 1st February 11:37
If you go external, you can mount the pump almost anywhere as long as it is below the tank, and has an adequate gravity fed supply.
Or in-tank
http://houseofboost.com/features/aeromotive_C6inta...
Or in-tank
http://houseofboost.com/features/aeromotive_C6inta...
andygtt said:
am I being thick, but in that example they hang the pump... doesnt that mean its sucking rather than being gravity fed?
I've been thinking that my pump has to be on the very base of the tank?
It isnt sucking as such. The intake on the pump is at the lowest point sitting in a reservoir of fuel.I've been thinking that my pump has to be on the very base of the tank?
I guess when the level of fuel in the tank is below the actual workings of the pump, there may be a small element of suck. But generally speaking, as the intake is always sitting in fuel, it doesnt have to work to lift the fuel.
Max is taking a different route with design. Placing the tank low, although not sure if it is actually inside the tank ?
The HOB setup linked is very good though. No different to any in-tank mount really...just much bigger and nicer.
stevieturbo said:
Max is taking a different route with design. Placing the tank low, although not sure if it is actually inside the tank ?
it is inside the "envelope" of the tank, but not actual "in" the tank (as in not wet with fuel. Putting the pump in an "arch" in the base of the tank means nothing sticks out the bottom, the pump is easy to mount or get to, and it can directly pick up fuel with a low "head" from the trap doored anti slosh zone.Max_Torque said:
it is inside the "envelope" of the tank, but not actual "in" the tank (as in not wet with fuel. Putting the pump in an "arch" in the base of the tank means nothing sticks out the bottom, the pump is easy to mount or get to, and it can directly pick up fuel with a low "head" from the trap doored anti slosh zone.
Sensible design, would make wiring the pump that bit easier. Doesnt kill the noise aspect an in-tank install would thoughAnd using the typical aeromotive filter pre-pump would be awkward. Although if an in-tank gauze could be fitted, that would be enough before the pump
stevieturbo said:
andygtt said:
am I being thick, but in that example they hang the pump... doesnt that mean its sucking rather than being gravity fed?
I've been thinking that my pump has to be on the very base of the tank?
It isnt sucking as such. The intake on the pump is at the lowest point sitting in a reservoir of fuel.I've been thinking that my pump has to be on the very base of the tank?
I guess when the level of fuel in the tank is below the actual workings of the pump, there may be a small element of suck. But generally speaking, as the intake is always sitting in fuel, it doesnt have to work to lift the fuel.
Max is taking a different route with design. Placing the tank low, although not sure if it is actually inside the tank ?
The HOB setup linked is very good though. No different to any in-tank mount really...just much bigger and nicer.
ive decided to mount it in tank... on rubber bobins (gotta find some petrol resistant ones now) and then make a sump within the tank... the pump will not fit in this sump as there is not enough room for it without the sump becoming the entire bottom of the tank so it will sit in petrol that when it goes below a certain level wont be able to be used.
yes i will have dead weight as i do now with petrol that can be got out... but it will have the effect of cooling the pump and deadening the noise.
well i hope so anyhow.
andygtt said:
TBH im not understanding how they can say the pump has to be lower than the pickup when the pump is external but then mount them 2-300mm from the base of the tank in their custom in tank applications.
Dont get what you mean at all ? A pump mounted 300mm from the base, could never lift any fuel below a level of 300mm .What exactly are you referring to ?
All internal pumps will sit low in the tank.
What I mean is if the pump is hung in the tank then at some stage the fuel will be well below the pump.... hows that different than if it was hung outside the tank in the same way which is what they say not to do? I have looked a quite a few examples on the Aeromotive site and many of them show the pump suspended around halfway in the tank not at the bottom.
With regard the A1000 in their sump, is it solid mounted or rubber?
With regard the A1000 in their sump, is it solid mounted or rubber?
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