Dual fuel tank option?

[BigBlueBus]

I've been pondering the idea of adding a second fuel tank to my Sprinter. I think it would be easier to hang another plastic tank (from the junkyard) under the floor, then adding a hose adapter, one 2" diameter at the bottom, one 1" diameter at the top (for vent), connect both to the original tank and voila!:clapping:

I'm currently getting about 500 miles on a tankful, but it would be great to have to fill up just half as often.

Has anyone attempted this? Any problems that I may encounter, besides the possibility of blowing up my van, garage and myself, in the process?

thanks,
John

[jdcaples]

I've been pondering the idea of adding a second fuel tank to my Sprinter. I think it would be easier to hang another plastic tank (from the junkyard) under the floor, then adding a hose adapter, one 2" diameter at the bottom, one 1" diameter at the top (for vent), connect both to the original tank and voila!:clapping:

thanks,
John

Is this right? (I welcome corrections, btw)

The fuel pump module is installed on the top of the tank. It contains the electric fuel pump (aka transfer pump, or lift pump), fuel reservoir, fuel guage sending unit (measuring the level of fuel in the tank), fuel supply line (to the high-pressure pump) and return line. I'm guessing that the lift pump is designed to overwhelm the high-pressure pump so the return line returns "warm" fuel to the primary tank.

If the fuel's too warm, it goes though some cooling apparatus before splashing back into the tank. If it's not too warm, it bypasses the cooling apparatus.

As long as you don't interfer with the labor of the fuel pump module - or the temperature regulation apparatus - I don't see a logic problem.

I do have a couple of implementation questions:

As you fill the tank(s), what would stop the fuel (entering the secondary tank) from spilling out the secondary tank's (top-side) vent?

As the primary tank empties via the fuel (lift) pump module (installed on the top of your primary tank), how would the primary tank receive replacement fuel from the secondary tank? Gravity?

Oh, and please describe your fittings and tell me why it'll never leak. :)

-Jon

[BigBlueBus]

It's simply a matter of basic plumbing. By connecting the two tanks with a large diameter hose somewhere near the bottom of both tanks, the fuel will be free to transfer from one tank to the other via gravity, either while filling or emptying; by connecting the two tanks with a small diameter hose at the top of both tanks, the tanks will be able to vent; the vent hose on top will be connected to the other tank, so no fuel will be able to escape. As far as the adapters themselves, they are readily available at any parts store and are pretty much leak proof.
As fas the lift pump, or sending units are concerned, it should not matter if the van has a 25 gal. tank or the equivalent of a 50 gal. tank. I have not looked underneath for the best placement yet, though. I'm thinking the passenger side would be best so that the vehicle is balanced.
Did I miss anything else?

John

[blakej59]

I'm with you on a desire to extend the range of this vehicle. I've contacted all the known aftermarket tank builders in USA and none have tackled this vehicle yet. I'm a long trip driver and extending the range is one of my most-desired changes. Also, with the price of fuel differing greatly as you travel, reducing the need to stop as often allows for sometimes huge savings. I've been forced to buy the $3.50 fuel only to discover $3.05 an hour down the road.

Another thread indicates there are larger tanks available for 2007 models in Europe but I haven't yet looked into that. Seems this would be an easier way to work it out. Hopefully you can use all the existing plumbing on a larger tank. I know that exhaust runs down the passenger side of the van but I haven't looked so see if a second tank could be mounted in the space prvided.

Hopefully someone will know additional info pertaining to this quest. There always seem to be some pretty clever people on this site.

Jim

[BigBlueBus]

I'm sure we can use a tank from a junkyard; it would be easiest to get one from a van, like Chevy or Ford, since they have a relatively flat floor like the Sprinter, also you can use the same straps. As soon as the weather gets a little warmer, I will definitely be adding another tank. I'm sure there's more than enough room for this under the Sprinter's massive floorplan.
My only concern: are there any side effects to using a gasoline tank for storing diesel? I would not think so, but I will do a little more research on this to find out.

It would be sooooo sweet :drool: to go from Chicago to Florida (1000 miles) on one tankful:cheers:.

[mean_in_green]

There's another way: there's space for much larger tank where the original one resides. I've got a 190 litres one, and I think I'm correct in saying a 240 litres one is available.

In aluminium, uses factory sender and retains cooling coil as described previously.

Fuel gauge still functions correctly too.

It's a tight fit on the dually because the UJ in the prop is bigger apparently.

If it warms up a bit this weekend I'll take some photos, but the bottom is flat so there's not much to look at - it basically fills the nearside from the back of the front wheel to the front of the rear wheel.

Simon

[jdcaples]

... for those that don't speak metric:

190 litres is about 50.2 gallons US

240 litres is about 63.4 gallons US

Oh, and if you irreversably damage your 25 gallon North American diesel tank, I believe it's a $350.00 US hunk of molded plastic.

BigBlueBus: I don't think you missed anything from my spectator point of view.

-Jon

PS: if there was a lift pump in the mix, I'd put a filter on one of the lines as a handy place to polish and circulate the fuel.... but that's me. I like filters.

[BigBlueBus]

There's another way: there's space for much larger tank where the original one resides. I've got a 190 litres one, and I think I'm correct in saying a 240 litres one is available.


Simon

Your 190 litre tank, was that stock or a retrofit? Also, do you have it in a NCV3 or T1N?

What would you estimate the cost to purchase a 50 gal tank down there and ship to USA?

Although, I like the idea of a balanced weight with dual tanks and it would not be too complicated to do.

JD, you're right on the lift pump and filters; My Vette has dual tanks, one on each side and a small pump to circulate the fuel from one side to the other, but no filter.

[mean_in_green]

What would you estimate the cost to purchase a 50 gal tank down there and ship to USA?



Retrofitted to a T1N.

Do a search for ACGB. The fairly basic website belies the splendid quality of their workmanship: hand crafted in aluminium with exquistely laid welds. I think the biggest one they do for a sprinter is lighter than the standard plastic tank. Your kerbweight rating may need altering in some regions.

A bolt on solution which utilises factory sender is a plus.

Price varies according to size. Last time I looked they were £7/800 including VAT.

Lightweightness won't count for much in shipping as a volumetric calculation is used. I would've thought you could get it shipped for £50 to £100 though.

__________________________________________________ __________________________________________________ ___________

Edited: Seems the website's been reworked - link: http://www.acgb.com/uk/home/actu.php?id=9&titre=high-capacity-tanks-for-luv

Simon

[BigBlueBus]

Well I looked underneath my van this morning and learned that it would be very easy to add another tank underneath...plenty of room. It would be much cheaper to just add another used plastic tank than try to special order something. especially since I'm in the USA.

John

[jfmason3]

I am brand new to Sprinter-Source and not yet a Sprinter owner. I am interested in knowing if any of you have knowledge about the possibility of adding the ACGB large fuel tank to converted Sprinters, esp. the new Roadtrek Adventurous RS. Have spoken to a few dealers and they are clueless.

[mean_in_green]

?!

Yes, I've got the ACGB 190 litres tank.

A quick re-read of the previous messages in this thread should prove informative.

Simon

[GalenEvans]

It's simply a matter of basic plumbing. By connecting the two tanks with a large diameter hose somewhere near the bottom of both tanks, the fuel will be free to transfer from one tank to the other via gravity, either while filling or emptying; by connecting the two tanks with a small diameter hose at the top of both tanks, the tanks will be able to vent; the vent hose on top will be connected to the other tank, so no fuel will be able to escape. As far as the adapters themselves, they are readily available at any parts store and are pretty much leak proof.
As fas the lift pump, or sending units are concerned, it should not matter if the van has a 25 gal. tank or the equivalent of a 50 gal. tank. I have not looked underneath for the best placement yet, though. I'm thinking the passenger side would be best so that the vehicle is balanced.
Did I miss anything else?

John

Hi John,

I've been thinking along the same lines. I'm assuming any bulkhead connector one would attach to the existing tank would require access to the inside of the tank to place and tighten the fitting. Is there an access for your hand?

Position the bottom elevations and hose connections for your aux tank carefully for two reasons: avoid a large heel that cannot drain; and empty the aux tank soon enough that the "low fuel" warning works correctly. Having the low fuel light come on when you know you have 15 or 20 usable gallons left seems like it would defeat the purpose.

I was thinking about using thru-hull fittings from West Marine for the purpose. Brass for about $35 or Plastic for less than $7. I don't have the courage to try this one on a fuel tank, but it looked like fun: http://www.truetex.com/bulkhead.htm

Lastly, completely filling up would likely wind up requiring patience as liquids transfer slowly when there is very little difference in head (elevation between the liquid surfaces). Maybe just always fill up with the driver's side elevated. :thumbup:

Galen

[BigBlueBus]

Galen,
I think I have a better idea; I just found out that Ford has a 55gal. option for their Econoline vans with Diesel engine. I have found alot of them used for around $50-$100. It would just be a matter of lowering the tank in the Sprinter and see if the sending unit (lift pump/fuel level arm, etc) will fit inside the Ford tank. :idunno: At least I won't have alot of money invested in case it does not work, in that case, I can always fall back on the dual tank idea.:rad:

:thinking:

John

[blakej59]

My thought on the dual tank option is to use the in-tank fuel pump that can be turned on manually when you wish to transfer fuel to the main tank (the OEM tank). The connection could be made in the neck of the main tank or for that matter, anywhere on the main tank (perhaps on a return line into the main tank). I know econoline fuel pumps are in-tank pumps. Others are likely the same. I'm not sure about how to fill the second tank.

Another thought although maybe not practical. There are lots of fuel tank options for boats. They're plastic and all kinds of shapes and sizes. I thought about mounting one inside the van, strapping it to an exterior wall and hooking a gravity feed with a valve that's manually opened when you wish to transfer fuel to the main tank.

I still think replacing the main tank with a larger, aftermarket tank that uses all the same fittings would be easiest. You don't have to mess with how to fill or how to transfer, etc.

I'm real interested in this issue but haven't spent the time. Hopefully one of you, who are a lot smarter than I, can work it out.

Jim

[BigBlueBus]

My thought on the dual tank option is to use the in-tank fuel pump that can be turned on manually when you wish to transfer fuel to the main tank (the OEM tank). The connection could be made in the neck of the main tank or for that matter, anywhere on the main tank (perhaps on a return line into the main tank). I know econoline fuel pumps are in-tank pumps. Others are likely the same. This is a good idea as well, there would be no need to add bulkhead adapters to either tank this way.I'm not sure about how to fill the second tank. I could simply put a Y-adapter right above the original tank, so that when that tank is full the fuel being pumped into the fuel door opening will be diverted to the second tank.


I still think replacing the main tank with a larger, aftermarket tank that uses all the same fittings would be easiest. You don't have to mess with how to fill or how to transfer, etc. This will work as long as the lift pump/sender assembly can be inserted into the new tank; but I think the dual tank method above will work well.

I'm real interested in this issue but haven't spent the time. Hopefully one of you, who are a lot smarter than I, can work it out.

Jim

Now, it's time to look for a suitable tank of about 20-25gals. that will fit in the space underneath. Ummm...Can't wait for the weather to get warmer now.

John

[VanSyncro]

I've been looking at this problem and have been preparing a solution for the first gen vans. The problem as I see it is that I don't want a separate filler since the factory one is so well integrated and secure, but I want to have the aux tank as a true reserve tank so I've sourced a pump that will pump both ways at about 6 GPM so I might have to slow my pumping a bit during fill to load the aux tank. When I get low on fuel then just flip a switch and dump the contents of the aux to the main. Now I just need to get down to the dirty work of designing and fabricating the tank(s). I might replace the original tank with fabricated larger tank as well since I'll have to drop it to make the connection.

Ian

[jdcaples]

I placed a document on the Auxiliary Diesel Fuel Tap in the NCV3 Database section.

Click Here (http://sprinter-source.com/forum/attachment.php?attachmentid=5848&d=1200953560)

[jimbobmw]

Just curious, how did your tank addition go? I wondered if you considered that if parked with one side higher than the other, wouldn't the fuel in the higher tank force fuel in the lower tank out...if nearly full, obviously. I have a 2004 that I would like to extend the range on.

[blakej59]

Has anyone tackled the larger fuel tank or dual fuel tank? Looking for the best way to take on adding capacity.

[KMDE]

Been two years and still not a cheap sound solution? I would love 50+ gallons lowering fill ups to once a day maybe. Spending 1400 is not a option.

[gary 32]

Been two years and still not a cheap sound solution? I would love 50+ gallons lowering fill ups to once a day maybe. Spending 1400 is not a option.

These people sell well engineered products mounted between the spare and rear axle on a Sprinter.
25 extra gallons installed complete 1152.00.

Hours: Monday thru Friday 7:30 AM - 4 PM (Pacific Standard Time) Closed Sat. & Sun.
Aero Tanks
379 S Sierra Way, Suite A
San Bernardino, CA 92408
(909) 388-0002