reserve fuel tank ideas

Howard Jones

Supporter
I would like to poll the forum on the subject of reserve fuel tanks. I have a track-only SLC and I am thinking of adding a 1-gallon reserve tank to the car in the spot next to the installed fuel tank. I am currently thinking of a separate fuel pump and tank. I should add that I am running a Hollet type 4 barrel carb so my pressure requirement is 5-10 PSI and I would use the reserve to slowly return to the paddock so a rather low GPH flow level is needed.

My main question is in reference to the plumbing as in how to fill the reserve tank at the same time as the main tank, hold fuel in it until requested, and not create a reverse flow problem of some sort. I can make everything such as tanks, hoses, mounting brackets etc. so I don't need sources really just a concept to work from.

Any Ideas folks ?
 

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
Reserve tank could very well serve regular duty as a swirl-pot and that would simplify your entire system while adding a gallon of ready to use capacity.
Other than motorcycles, I guess I never really saw any use for reserve capacity...
 

Ian Anderson

Lifetime Supporter
I would like to poll the forum on the subject of reserve fuel tanks. I have a track-only SLC and I am thinking of adding a 1-gallon reserve tank to the car in the spot next to the installed fuel tank. I am currently thinking of a separate fuel pump and tank. I should add that I am running a Hollet type 4 barrel carb so my pressure requirement is 5-10 PSI and I would use the reserve to slowly return to the paddock so a rather low GPH flow level is needed.

My main question is in reference to the plumbing as in how to fill the reserve tank at the same time as the main tank, hold fuel in it until requested, and not create a reverse flow problem of some sort. I can make everything such as tanks, hoses, mounting brackets etc. so I don't need sources really just a concept to work from.

Any Ideas folks ?
Hi Howard.
A connection into the outlet from your main tank, through a one way valve to the bottom of the spare tank. Spare tank will need a top breather/vent.
Fill main tank and it will also fill spare tank, via said one way valve.

you could also T into same pipe to feed the secondary / reserve fuel pump

plumbing would be, from bottom of main tank, through 1 way valve, through T piece to reserve tank. The other part of T would feed the secondary pump / filter / carb

Ian
 
What about a solenoid valve, No Tee as above and a vent between the main and reserve tank. when the main tank is full open the solenoid to fill the reserve tank. If you run out, open the solenoid again releasing the fuel back into the main tank. No need for additional fuel pumps etc. On second thoughts, a manual valve with a lever in the cab might also do the trick.
 
I'm not following the need for a "reserve" unless you want to run out of gas, then have a little extra. I would prefer to have uninterupted fuel flow until there was nothing left but vapor.

A 1 to 2 gallon surge tank would get that. If you have a spot in the dash where you could add an additional level gauge, you could have one in the surge tank, and as it falls from full, you know you're on the last few sips. Or you could have a warning light come on when the surge tank is below 3/4. I'm guessing it would intermittently light as you start pulling air from the main tank(s) until it stayed on, then you know you're down to the last 3/4 gallon.

I'm still noodling on what I'll do, but I'm planning 3 pumps. One in each tank to fill the surge tank, and the high pressure EFI pump in there to feed the engine.
 

Howard Jones

Supporter
Brian, Running out of fuel during a track event and holding up everyone else up while you get towed back is bad form. Something I have been able to avoid and want to in the future. I have had a few close calls, however. My car uses 5.5 gals per 30 min session and I try and not haul around unneeded fuel if I can. I expect the new motor to make about 100HP more so it will use more fuel, thus the idea of a reserve tank and aux fuel pump when it begins to run low on fuel. Carbs give you a couple of coughs before they are completely dry so all I will need to do is turn on the aux pump and return to the paddock.

Ian............Like this?
 

Attachments

  • IMG-0934.JPG
    IMG-0934.JPG
    304.6 KB · Views: 165
Last edited:
That setup is brilliant and simple. The regulator will keep the reserve full until it's needed. I think you could further simplify it using a single regulator.
 

Howard Jones

Supporter
Sorry about the upside-down. Sometimes this just happens and I am not computer geek enough to fix it............I tried.

Brian, I think I will go with an internal regulated pump for the aux one. It doesn't need to flow a rate any more than enough to keep the carb full as I take an easy back to the pits. This would be 4-5 min at low power/speed at worst.
 

Ian Anderson

Lifetime Supporter
Howard, certainly that would work.
I would have changed it slightly to only run one regulator, but they are not overly expensive so a bit of built in redundancy!

ian
 

Howard Jones

Supporter
Ian. That's another great Idea. I looked for a valve that was electrically actuated and had AN-8 capable ports. All I came up with was a really high-cost boat multi-tank, $$$$ and aircraft twin tank valves, $$$$$$$$$$$$$$$$$$$. I'll keep looking for a RV-type deal but the -8 port thing makes it pretty limited pickings.

Thanks for the help. Now I know what I need to do anyway.
 

Ian Anderson

Lifetime Supporter
How about 2 solenoid valves to a T piece instead of Pollack?
various sizes here for not huge money

Ian
 

Howard Jones

Supporter
So Here's the actual reality of fuel gauges when you are on track and at pace. First, it isn't easy to look at the oil pressure and water temp gauges (that's why I have warning lights for them) let alone try to read a fuel tank level gauge. Second, there are NO fuel level gauges that are responsive and accurate enough to let you know when you are down to the last lap worth. That would be about a 1/2 gallon. The sloshing around in the main tank can be picked up but it is nearly impossible to ACCURATELY read 3/4 of a gallon sloshing around in a 14-gallon tank.

You could install a fuel pressure sensor and an idiot light (in your face) but that would only tell you that you ran out of fuel. Well, that is something you already know because you just lost power. If you cannot accurately sense the last 1/2 - gallon or so in the tank then all the gauges, idiot lights, and sensors in the world won't help.

So what you need is a separate tank that holds, let's say a gallon, fills, and remains filled with the main tank, does not require any separate filling and refilling but reserves the last gallon for use SEPERATELY from the main tank, and can be used when the main tank is dry.

The goal I am exploring is to be able to run the car 30 mins at a time, not get stranded on track, and not haul a lot of extra fuel weight around all day long so I don't run out. The other thing is you CAN run the main tank out, know it is empty, and just how far you went on the last can of gas. Then be sure just how much fuel you put back into the main tank. All without being that guy who ran out of gas.

None of this is remotely applicable to a streetcar.

So that's why.......................................


Ian,

if you use a manual valve then you would need to be able to get your hand on it from your belted-in driver's seat. That means fuel lines in the cockpit. Getting out of the car to access a manual valve elsewhere in a track setting isn't allowed unless you are on fire. As well, not only is that never going to pass any competent tech inspection but it's just a very bad idea IMHO.
 
Last edited:

Ian Anderson

Lifetime Supporter
So Here's the actual reality of fuel gauges when you are on track and at pace. First, it isn't easy to look at the oil pressure and water temp gauges (that's why I have warning lights for them) let alone try to read a fuel tank level gauge. Second, there are NO fuel level gauges that are responsive and accurate enough to let you know when you are down to the last lap worth. That would be about a 1/2 gallon. The sloshing around in the main tank can be picked up but it is nearly impossible to ACCURATELY read 3/4 of a gallon sloshing around in a 14-gallon tank.

You could install a fuel pressure sensor and an idiot light (in your face) but that would only tell you that you ran out of fuel. Well, that is something you already know because you just lost power. If you cannot accurately sense the last 1/2 - gallon or so in the tank then all the gauges, idiot lights, and sensors in the world won't help.

So what you need is a separate tank that holds, let's say a gallon, fills, and remains filled with the main tank, does not require any separate filling and refilling but reserves the last gallon for use SEPERATELY from the main tank, and can be used when the main tank is dry.

The goal I am exploring is to be able to run the car 30 mins at a time, not get stranded on track, and not haul a lot of extra fuel weight around all day long so I don't run out. The other thing is you CAN run the main tank out, know it is empty, and just how far you went on the last can of gas. Then be sure just how much fuel you put back into the main tank. All without being that guy who ran out of gas.

None of this is remotely applicable to a streetcar.

So that's why.......................................


Ian,

if you use a manual valve then you would need to be able to get your hand on it from your belted-in driver's seat. That means fuel lines in the cockpit. Getting out of the car to access a manual valve elsewhere in a track setting isn't allowed unless you are on fire. As well, not only is that never going to pass any competent tech inspection but it's just a very bad idea IMHO.

Have a "tap" / change over valve in the engine bay with a pull cable into the cockpit. You only need to pull it once to swap the valve to the other tank and once back in the pits manually change it back.

Ian
 
Back
Top