Surge Tank

[kfxnando]

Hi!!

as things go on, so the small questions come up for all the small details, and who better to call on then the guys who have already done such conversions!!

the vehicle has a low pressure fuel pump, by the tank, from the factory!!

have a choice, of either replacing that pump, with a high pressure EFI pump, and replacing all the pipes accordingly, or using the pipes as they are, and have surge tank and a high pressure fuel pump in front, under the bonnet!!

have on my own decided to go with the surge tank, mainly basses on what I have read!!
so unless someone can show me that this is completely wrong, plan on going this way!!

already have the main piece of tubing for the tank, in stainless steel!!
having issues with webshots, so will post pics of that later!!

as for the fittings just need to get the size of fuel pipes that I will be using and then will deal with those small issues!!

good chance will have custom ones made, there is more then one person with a lathe, that has offered help!!

so far so good!!

so if any one would care to share the pics of their surge tanks, or give some advice, would be great, it would save me having to reinvent the wheel, have seen one on a vehicle, however does not make sense the way its done!!

the one I saw, has the low pressure fuel feed, and return on top of the surge tank
and
the feed for the EFI pump comes from the bottom of the tank, as does the return from the EFI fuel rails!!

now, my limited logic tells me to have the return from the EFI rails also into the top of the tank
could be missing something, as that is also low pressure!!
my experience with this is almost Zero

will need to do a search on this one!!

all advice and info will be highly appreciated!!

[zepplin]

Leave the LP pump at the tank to feed the surge tank (HP pumps don't like to 'suck'). The feed from the LP pump to the surge tank should be halfway up the tank & the return to the main fuel tank should be from the top of the surge tank on the LP feed side. The feed from surge tank to HP pump should be from the bottom of the surge tank (on the opposite side of the tank to the LP feed & tank return) & the return from the fuel rail should be into the top of the surge tank above the HP pump feed.

Hope this makes sense.

[kfxnando]

a very big thanx Steve!!

makes plenty sense, that also how I though it should work, however the one that I saw was very confusing, while you replied, found this great info, witch just confirms what you have said!!

the surge tank on the pics, is very nice and gives me some great ideas!!

http://www.toyotaperformance.com/surge_tank.htm

thanx again Steve!!

[CasKru]

My setup:

Tank, fuel filter , Low Pressure pump, Surge tank, Fuel filter (high pressure), High pressure pump, Fuel Rail, Fuel pressure Valve, Surge Tank

Fuel from tank through filter to surge tank by LPP. From surge tank through filter to fuel rail etc back into surge tank by HPP.

Both pumps run absolutely quite and the return from the fuel rail runs back into the surge tank.

[kfxnando]

Surge tank is just over 1.1L

material is about 1.5, so I have been told, the people where I got the material, although extremely helpful, were not too sure!!

looks like webshots is up again!! so here come the limited pics!!

here is the piece of SS being cut


and here is the one piece on the dash of the 4x4


and so all things start, with small steps!!

[Family_Dog]

They say a picture is worth 1000 words...

-F_D

[Hoppy]

No std vehicle uses the surge tank in front for safety reasons and heat build up.

If you have to run a surge tank, fit it under the vehicle like the golf 2/jetta 2, they run a K jet system that uses a higher pressure and volume pump than modern EFI systems, you can use that pump/surgetank setup.

I prefer to fit a bafle system in the tank and run a submersable pump, the fuel stays cooler.

[kfxnando]

Family_Dog, thanx for the diagram!!
makes perfect sense!!

Allan, you have a point about the heat and the fuel, will have a look and see if there is a convenient plate to place it under the vehicle!!
however that does leave a concern of one day ripping the whole thing off, when riding offroad!!
either that of behind the left head light, or where the current power steering fluid bottle is mounted!!

will keep the heat issue in mind when looking at a place to mount the whole set up!!

thanx guys, some great info, and you can keep the ideas coming!!

thanx!!

[kfxnando]

well here is an update, on the tank!!

this morning all the material that I had!!!



this afternoon, after about 2hrs work

[zepplin]

and here is the one piece on the dash of the 4x4

Probably not the best place to mount it as it might obscure the view of the GPS - not to mention Allan's concerns too.

[kfxnando]

actually mounted on the dash, will be easier to keep the fuel cool, with the ease of the aircon!!

[Hoppy]

No jokes, some cars do run the fuel suply through an aircon duct, we had limos that did slow parades and idled for long periods that had this mod, can work for off road driving!

[kfxnando]

No jokes, some cars do run the fuel suply through an aircon duct, we had limos that did slow parades and idled for long periods that had this mod, can work for off road driving!

well sounds like a great idea, however sounds like extra work!! maybe later once the project is done and all sorted, it could be a follow up project!!

as it is dont see me being finished till late this year!! :evil: :evil:

have read on here, that someone was busy looking at cool air for the motor instead of hot air from the engine bay, maybe someone else could do the one of running the fuel pipe past the aircon as the 1st one one here!!

know that all those little things can add up!!
know that on some of the top fuel dragters, the way the fuel pipes run and the bends have an influence on power!!

so who will start this one???

[kfxnando]

well the SS tank became a problem and decided to make one out of mild steel, and it was, sadly did not take any pics, did every thing welded it up, only one small leak on the ends, easily fixed, then came the other leeks, around the fittings, do ended up with bigger welds then what I would of liked, however, it does not leak!!

we tested it to around 2.5bar, around 35 Psi, and it was holding, then as murphys law would have it, someone showed up,and said, nope will make you one out of SS, and did not even take my material, just took the fitting with, he said he would make me one in SS!!

EISH, all that work and expense for the perfect solution to come in the end!!

will try and post some pics as soon as I have some pics!!

[Spartan]

My anti-surge tank is uit aluminium gemaak en werk soos n droom met sy twee HP pompe

[Demon]

So I take it you are going to use pipe clamps on your whole set up ? If it were me I would out source fittings. Pipe clamps will start to leek sooner or later.

[kfxnando]

So I take it you are going to use pipe clamps on your whole set up ? If it were me I would out source fittings. Pipe clamps will start to leek sooner or later.

sorry for being a little slow, could you pls give a better description or some pics!!

not quiet sure what you mean, however always up better ideas then what I have!!

thanx

[Demon]

Look at the lines on this tank. Braided hose with AN fittings.

Here's a link on how to cut and join them, won't be cheap but gives you peace of mind about leeks.

http://www.stockcarproducts.com/aqp1a.htm" onclick="window.open(this.href);return false;

[kfxnando]

thanx VERY much Derrick

will defiantly have a look at those!!

that looks very neat, not sure how my system will turn out!! thanx again

think the high pressure side might do well with braided hoses!!

as soon as the tummy bug is gone will do some shopping for that one!!

[Demon]

No problem. Ya maybe use it on your high side and use pipe clamps on your return

[Spartan]

will defiantly have a look at those!!

that looks very neat, not sure how my system will turn out!!

Kry ook vir jou hartpille want daai braided hose in M..er duur

[kfxnando]

will defiantly have a look at those!!

that looks very neat, not sure how my system will turn out!!

Kry ook vir jou hartpille want daai braided hose in M..er duur

well that might not be too much of a issue, unless they cost more then their weight in gold, was just thinking, do have somewhere some braided hose, just cant remember what ID, just need to go look for them!!

and even better have my new SS Tank, looks great, just a bit heavy was made out of 3 or 4mm thick SS, any case great welding!!

again will take some pics, as soon as me better to run around outside!! tummy bug, still bugging !! got it bad this time!!

[swartvark]

I also need a surge tank!
Did you ever take those pics?

[zepplin]

Tiaan, try giving the Ferroli's a call. They are in Killarney Gardens and build surge tanks for racing cars. They have come up with a nifty idea where they mount the HP pump inside the surge tank to save space. 021 556 6567 and speak to Giovanni.

[swartvark]

Tiaan, try giving the Ferroli's a call. They are in Killarney Gardens and build surge tanks for racing cars. They have come up with a nifty idea where they mount the HP pump inside the surge tank to save space. 021 556 6567 and speak to Giovanni.

Hoppy will fit one for me.
Thanks

[GeorgeJvR]

What is the advantages of a surge tank?
I'll go the EFI rought sooner or later.

[kfxnando]

I also need a surge tank!
Did you ever take those pics?

sorry sorry sorry for not posting the pic sooner!!

it has been on my page for a long time just did not post the link!! sorry!!

pic not very clear, however will take more if needed!!

[RooiLux]

What is the advantages of a surge tank?
I'll go the EFI rought sooner or later.

Sal self like om te weet,my bakkie word juis nou ge-efi

[swartvark]

Om dit eenvoudig te stel:

Dis 'n klein tenkie tussen jou hoof tenk en die efi pomp wat vol petrol bly en dus verhoed dat jou voertuig wind sluk wanneer die petrol in jou hoof tenk weg beweeg van die pick-up pypie af.

Swartvark sluk bv wind as sy tenk kwart vol is en ek vinnig wegtrek. Dit sal teen 'n styl helling ook gebeur.

[RooiLux]

So wat jy nou vir my sê is al is my bakkie ge-efi en ek gan ry trials gan hy nogsteeds vrek? :wth: :wth: :wth: Dis nou nie eintlik wat ek wou hoor nie so ek hoop nie dis wat jy bedoel nie?

Indien dit wel is hoeveel gan dit kos om 'n surge tank te maak en te instaleer om die probleem op te los en is dit 'n maklike proses??Indien dit wel 'n probleem gaan wees op my bakkie?

Ek het juis ontslae geraak van die carb agv stalling en om nou tehoor dit gan nogsteeds gebeur na duisende rande raak ek effe moedeloos!

Of verstaan ek jou nou verkeerd?Ek hoop so!

[swartvark]

Ek dink dit behoort as standaard deel van die EFi conversion te wees.
Hier is ietsie vannie internet af.
Diy Surge tank




Anyone converting a car from a carburettor to fuel injection (EFI) might well find the need for a surge tank to prevent fuel starvation when running at a low fuel level or under hard cornering. Stock fuel tanks in older cars don’t have any kind of in built design to prevent this situation other than simple baffles, but how does it occur and what’s so different with fuel injection? The fuel pump in a car equipped with a carburettor pumps the fuel at quite low pressure and at a relatively slow speed from the tank to the carb. Should the fuel ever slosh away from the pickup pipe inside the tank uncovering it and allowing air to be drawn in by the pump, the engine will happily continue running regardless as a carburettor has it’s own in built reservoir of fuel in the float chamber. By contrast, an EFI pump runs at very high pressure and the fuel is circulated to the fuel rail and back very rapidly, so should the pickup become uncovered momentarily the pump could literally draw in so much air that it would purge all of the fuel from the entire system in a moment. Suddenly the injectors would be getting no fuel and the engine could even cut out. This is particularly risky with a turbo engine. A sudden lean mixture condition at speed could result in serious engine damage. So having established that a fuel surge tank is a good idea, how does the system work and how do we go about making and installing one? Read on….


The idea with a surge tank is to provide a permanent reservoir of fuel to feed the EFI pump that won’t be affected by hard cornering, acceleration or low fuel levels in the main tank. The tank is usually tall and narrow with the outlet to the EFI pump near the bottom. The surge tank can sometimes be fed from the main tank just by gravity alone if it is mounted well below the main tank but more often than not, it’ll be fed by a normal low pressure electric fuel pump as used on many older car equpped with a carburettor. The low pressure pump pulls fuel from the main tank and feeds it into the surge tank near via an inlet near the bottom. The top of the surge tank has a return hose to the main tank and the low pressure pump circulates fuel between the two. Having the return at the top makes sure that there is no air trapped in the surge tank so it will always be full of fuel right to the top. If the fuel in the main tank surges away then the low pressure pump will draw in a tiny bit of air but it will immediately rise to the top and be purged from the surge tank, thus not affecting the EFI fuel supply. The diagram below illustrates the principle of the system…

surge_diag.jpg (18.83 KiB) Viewed 3685 times

You can of course buy a surge tank or have one made for you but if you have a welder and are a bit DIY minded, they why not make your own? The following method was used to construct a fuel surge tank to use in my 1971 Datsun 510 when I converted to to run a fuel injected engine (a Nissan KA24DE). The main component, the tank, is made from a small disposable CO2 gas welding bottle. These small gas welding bottles can be bought quite cheaply so even if you don’t use them on your own welder it’s not expensive to buy one purely for this purpose. The first thing to do is make certain it’s empty because you’re going to be cutting it up!! Do so by screwing on a regulator and opening it up to vent the bottle. The valve at the top of the bottle can be unscrewed and removed once it’s empty. You will need to do this to allow for the fitment of a fuel return outlet union in the top.

Once your tank is emptied, grind or sand the paint and any labels from the lower section so you can mark it to cut off the bottom. To mark a line straight around the bottom try wrapping a sheet of A4 paper around the bottle and using one edge as a guide to mark it. Once you’ve got it marked, cut off the end with either a small angle grinder and cutting disc or if you need some exercise, use a hacksaw. Once cut use a file to de-burr and flatten the open end. How far from the end you cut depends on how much room you have for the surge tank and the size of the bottle you are using. Make it as tall as you can.

The next job is to drill some holes in the bottle. The exact position of the wholes is not critical but they want to be arrange more of less as shown in the photo. The side with two holes is for the high pressure EFI circuit and the single hole is the feed from the main tank (the return is out of the top). Over these holes you will need to weld some nuts into which you can screw the hose unions. The size of these depends on the unions you are using. I used connectors which came from carburettors and off of intake manifolds, both of which had BSP threads. I chose some nuts with a bore smaller than necessary, then drilled and tapped them to suit the unions I had. Chamfer the back of the nuts so you can get good penetration when welding them on, then clamp them in place and weld them using plenty of power. These welds are important as they need to be fuel tight so it’s essential to get good clean welds. Once the nuts are welded, run a tap through them once more to make certain the threads are clean. It’s also a good idea to check the thread in the top of the tank where the valve was originally. if you are lucky, it will be the right size for you union, if not you may have to tap it out. If it’s too large for your fitting then weld on a nut as with the side unions. It is wise to tap all of the mounts in the surge tank before welding on the base otherwise you’ll end up with metal filings and swarf inside the tank.

surge9.jpg (61.69 KiB) Viewed 3685 times

Next stage is to clean out the inside of the tank thoroughly and then a base for it. The base is made from a piece of flat steel plate around 3 or 4mm thick. Make it big enough to accommodate an 8mm bolt in each corner, remembering to allow for the bead of weld that will hold it on. Once cut, drilled and prepared, weld it to the main tank with plenty of power. It helps if you chamfer the bottom edge of the tank a little to get good penetration. Again these welds need to be fuel tight so clean metal and smooth welds are essential.



Now that the tank is made, all that’s needed are some pipe unions. The unions i used, as I mentioned earlier came from carburettors and intakes. The two larger unions are brake vacuum servo connectors taken from intake manifold from old Nissan and Datsun engines. The small unions are fuel pipe connectors from carburettors from the same engines. These unions have tapered threads so you can wind them in really tight to get a seal. I have had no problems at all with any of them leaking so far.

surge13.jpg (41.11 KiB) Viewed 3685 times

The last job is to paint it then install the tank in the boot of the car. Use a reinforcement plate or at least some large washers on the mounting bolts under the boot floor. In the 510 I mounted it so that it was above the rear chassis leg, placing the mounting bolts either side of the leg under the floor. Be sure to connect the system with fuel hose suitable for high pressure use. I used a generic low pressure pump purchased from my local motor factor and the high pressure pump is a Bosch unit from a Vauxhall Carlton. The blue cylinder is a special pre-filter for EFI made by Systec which has a very high flow rate suitable for being placed before the EFI pump. This serves to protect the EFI pump from any tiny particles of dirt or rust from the main tank. Even the tiniest piece of junk will jam this type of EFI pump solid. If your fuel tank only has one outlet and no return, then the return from the surge tank can be run back into the main tank via to original outlet and a feed for the surge tank can be taken out of the tank drain by replacing the plug with an outlet fitting. If you only have one outlet and no drain plug then you may have to remove the fuel tank and modify it for a second connector.



This system can be adapted for different vehicles in many ways. For example, I used a similar principle to fuel inject a Nissan Prairie but on that application the surge tank had to go under the floor. The tank was made much shorter with the mounts placed at the top. It worked as well on the Prairie as the system shown above. The System in my 510 has been run without the slightest hint of fuel starvation on a race track with the main tank nearly down to empty. So there you have it, a surge tank system made for peanuts

[kfxnando]

great post Tiaan!!

if I was still looking for a surge tank, then would of followed the ideas that you posted!!