Extending the fuel range of an 88"

[tuko]

My 88" is built on a Designa coil sprung chassis that has a Designa custom fuel tank which is in the range of 43ish litres. When we are overlanding, I'm always watching the miles driven and planning well in advance for the next fuel stop, which I normally plan in the 320-350 km range. Some days....or I should say everyday we are having to fuel up 2 times. I do know that you can have duel tanks under the seat box for the series but I have the start battery and some electrics under the pass seat so that idea is basically out of the question for me as I was forced to move the start battery from the engine bay when I did the 300Tdi conversion.

So I've been playing with the idea of a 40L fuel cell under the rear floor just ahead of the rear cross member. That's vacant real estate in my eyes and a 40L fuel cell with the demensions of width 42cm, length 42cm and 23cm high would fit perfectly.

I see on many of the american overlanding sites they simply run an inline fuel pump that they switch on/off from the cab to cross fill into the main tank.

I'm wondering if anyone has done this with their SWB landy to extend their fuel/mileage range? Or have suggestions or tips or ideas that would extend my range with the 88". 

I should add that besides the above explanation of the current fuel range, we are planning a big trip (ok big for us anyways) to Spain next summer for 4-6 weeks. Having a more comfortable range with the landy is my goal for that and future trips.

 

Todd.

[Arjan]

We had a ArgoCat 50 Ltrs. tank in the rear of the 88" before the 1st rebuild for - like you - additional fuel and used a Jaguar electric pump to fill the standard under seat one. They fit nicely and make a difference.

However, these days we have just 2 cans as we rarely take the 88"on real long trips - also the FR MOT frowns on additional in board tanks...

[secondjeremy]

Where is your rear silencer?

 

[David Sparkes]

5 hours ago, tuko said:

My 88" is built on a Designa coil sprung chassis that has a Designa custom fuel tank which is in the range of 43ish litres.
...  Or have suggestions or tips or ideas that would extend my range with the 88". 

Todd.

I don't know the Designa chassis, or it's 'custom fuel tank', but I thought standard tanks used to be 10 Imperial Gallons, or ~50 litres, so that makes the Custom tank smaller than normal.

The modification I do recall is to replace the standard Series underseat tank with a Defender tank, which extends forward underneath the RH floor plate. There is some loss of ground clearance, but I'm not sure how much this will affect you. The 12 imperial gallon capacity primarily makes use of the space between the standard fuel tank outrigger and the standard bodywork outrigger ahead of it.
The standard forward outrigger for the Series fuel tank needs cutting off, and the bolt-on Defender item (possibly from the LH side) needs bolting in its place.

I thought I had a section with all the parts especially listed, but I've hidden it somewhere, so have had to go back to the standard list. This is a pity because I can't pass on the specific recommendation I had seen and recorded. So it seems all I can do is pass on the idea, you will have to do your own checking on parts availability etc.

Fuel tank was NTC 2008, with its internal fuel pump PRC7419 (or NTC2519 pickup unit if you have an external pump you can use) and fuel level sender unit (two options based on chassis VIN, so I can't even guess which would suit your circumstances.
The front mounting bracket is NRC 9474.

Double checking has found two 15 gallon tanks, both listed as an 'extra fuel tank', NRC 7040, and NTC2889, changing at VINs 243342 and 3.
Both use the front mounting NRC6829.
The early one uses an external pump, the later one uses an internal fuel pump PRC7018.

If you can fit in a 15 gallon varient that gives you at least 50% greater capacity, possibly just using dead space.
If you weren't already using the LH underseat space for a battery etc a second Defender tank could be fitted there, giving a total capacity of up to 30 Imperial gallons.
Are you sure sure you can't put your electrical bits and pieces in the dead space you found? 🙂

Regards.

[Snagger]

Surely it has to be better to move the electrics to a box behind the rear axle and have the larger void available for a second under seat fuel tank?

[tuko]

On 6/14/2020 at 4:49 PM, secondjeremy said:

Where is your rear silencer?

 

Inside the rear frame rail, but there is plenty of room to place a heat shield if need be.

[tuko]

On 6/14/2020 at 7:57 PM, David Sparkes said:

I don't know the Designa chassis, or it's 'custom fuel tank', but I thought standard tanks used to be 10 Imperial Gallons, or ~50 litres, so that makes the Custom tank smaller than normal.

The modification I do recall is to replace the standard Series underseat tank with a Defender tank, which extends forward underneath the RH floor plate. There is some loss of ground clearance, but I'm not sure how much this will affect you. The 12 imperial gallon capacity primarily makes use of the space between the standard fuel tank outrigger and the standard bodywork outrigger ahead of it.
The standard forward outrigger for the Series fuel tank needs cutting off, and the bolt-on Defender item (possibly from the LH side) needs bolting in its place.

I thought I had a section with all the parts especially listed, but I've hidden it somewhere, so have had to go back to the standard list. This is a pity because I can't pass on the specific recommendation I had seen and recorded. So it seems all I can do is pass on the idea, you will have to do your own checking on parts availability etc.

Fuel tank was NTC 2008, with its internal fuel pump PRC7419 (or NTC2519 pickup unit if you have an external pump you can use) and fuel level sender unit (two options based on chassis VIN, so I can't even guess which would suit your circumstances.
The front mounting bracket is NRC 9474.

Double checking has found two 15 gallon tanks, both listed as an 'extra fuel tank', NRC 7040, and NTC2889, changing at VINs 243342 and 3.
Both use the front mounting NRC6829.
The early one uses an external pump, the later one uses an internal fuel pump PRC7018.

If you can fit in a 15 gallon varient that gives you at least 50% greater capacity, possibly just using dead space.
If you weren't already using the LH underseat space for a battery etc a second Defender tank could be fitted there, giving a total capacity of up to 30 Imperial gallons.
Are you sure sure you can't put your electrical bits and pieces in the dead space you found? 🙂

Regards.

David,

the Designa chassis fuel tank is "trimmed" so that it clears the radius arm mount on the frame. By them trimming the lower edge of the tank I lost approx 3 litres. I never put any thought into the 90 fuel tanks, I think I have to get the measuring tape out to see if it's plausible. 

[tuko]

On 6/15/2020 at 10:14 AM, Snagger said:

Surely it has to be better to move the electrics to a box behind the rear axle and have the larger void available for a second under seat fuel tank?

Weight distribution, yes Nick you are right but I can think replacing the winch cables wouldn't be cheap (longer) plus relocating everything else. Also I just remembered that I did remove one of the tank mounts on that side of the frame years ago cause it was getting hung up a lot when offroading. But with that said, I'll take another look, maybe it would be the best alternative ?? 

[tuko]

Following along with the suggestions for the fuel tanks, here is what the tank looks like that I have today  (photo taken from the internet) 

 

So, a standard tank wouldn't fit on the pass side as it has to be "trimmed" like that above. 

[David Sparkes]

Looks like your original thought has stood up to the challenge of our second guessing! 🙂
Good luck.

Regards.

[Snagger]

20 hours ago, tuko said:

Weight distribution, yes Nick you are right but I can think replacing the winch cables wouldn't be cheap (longer) plus relocating everything else. Also I just remembered that I did remove one of the tank mounts on that side of the frame years ago cause it was getting hung up a lot when offroading. But with that said, I'll take another look, maybe it would be the best alternative ?? 

I think you’d get better fuel capacity as well as weight distribution, even with the trimming.  A battery box would be very shallow and would not need to stick down far below the chassis cross member.  A fairly flat rear fuel tank would have a lot of surging and sloshing compared to the more vertical front tanks.  I can see your concern with the cost of long battery cables, though.  Would a battery not fit behind the cross member aft of the transmission, above the exhaust and prop shaft?

[tuko]

On 6/17/2020 at 10:37 AM, Snagger said:

I think you’d get better fuel capacity as well as weight distribution, even with the trimming.  A battery box would be very shallow and would not need to stick down far below the chassis cross member.  A fairly flat rear fuel tank would have a lot of surging and sloshing compared to the more vertical front tanks.  I can see your concern with the cost of long battery cables, though.  Would a battery not fit behind the cross member aft of the transmission, above the exhaust and prop shaft?

I'm leaning towards the aux tank under the pass seat. I emailed Lian at Designa Chassis this week and he's informed me that Allisport is his official supplier of the fuel tanks for his frames. The price of the tanks do set you back but the quality is in the product. 

As for the battery location Nick, I have to spend so time under the vehicle to figure that out. I'm wondering though, I have several shorter pieces (2m) of 50mm cable, can a person maybe use a junction box to extend the leads for the winch? 

[Snagger]

I can’t see why you can’t extend the lead that way, and you only need the positive - the chassis works well as the earth, as long as you beef up the thickness of the attachment point with a welded on washer or plate.