Long Range Tank Questions (3 Viewers)

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Hi Fred,

I was hoping you wouldn't be bothered too much by a couple more clarifications. I just committed in an additional tank to dissect and use to for my LRT of your design.

The bracket that holds the rear of the tank in, has a series of six bolts. Did those bolts fasten through the floor, or was there an intermediary plate that fastened into the original bolts (only two)? I'm imagining the bracket (6 bolts) and an intermediary plate then then receiving additional bolts (4 minimum) in addition to the original two?

Or is that carbon steel bracket fastened to the frame, for instance, and then the 6 bolts through it into the aluminum flange?

Also on the rear of the tank, is that an angle sloping downward to match the original mounting angle? when the straps were used?
 
Hi guys, I've got two approximate designs going on here. I was curious to feedback/suggestions on minimum clearances from the ground.

Currently I am 17 inches from the front leading edge and about 20.5 from the rear edge to the ground; upward slope of 3.5 inches front to back. My mockup you can't even see the tank from standing behind it. It's approximately 42 gallons and every inch I increase it increases the capacity around 3.5 gallons. I.e., if I have capacity of 46 gallons, I'm 16 and 19.5 inches of clearance, front and rear of tank respectively.

On design two I have the leading edge parallel to the ground (for 14 inches toward the rear) at a height 17 inches off the ground and then a slightly greater departure angle to give 21.5 inches clearance. Adding an inch to the tank as above (reducing clearance by and inch: 16 & 20.5") will add around 2.5 gallons of fuel and lower as above.

If I can figure out how to attach some photos I'll do that later. Simply put however, what min clearances is suggested for moderate off roading/overlanding? I may try this in one of the other forums too, but would prefer to continue this one. Thx!

PS. Fred thanks for all the patience and help!
 
Hi guys, I've got two approximate designs going on here. I was curious to feedback/suggestions on minimum clearances from the ground.

Currently I am 17 inches from the front leading edge and about 20.5 from the rear edge to the ground; upward slope of 3.5 inches front to back. My mockup you can't even see the tank from standing behind it. It's approximately 42 gallons and every inch I increase it increases the capacity around 3.5 gallons. I.e., if I have capacity of 46 gallons, I'm 16 and 19.5 inches of clearance, front and rear of tank respectively.

On design two I have the leading edge parallel to the ground (for 14 inches toward the rear) at a height 17 inches off the ground and then a slightly greater departure angle to give 21.5 inches clearance. Adding an inch to the tank as above (reducing clearance by and inch: 16 & 20.5") will add around 2.5 gallons of fuel and lower as above.

If I can figure out how to attach some photos I'll do that later. Simply put however, what min clearances is suggested for moderate off roading/overlanding? I may try this in one of the other forums too, but would prefer to continue this one. Thx!

PS. Fred thanks for all the patience and help!

While I don't off road more than the occasional fire road/gravel road - I like the design where you can't see it from behind. I'm interested in a LR tank and will buy one. What's your timeline for completion?

Thanks-

Shane
 
I hope to complete it within a month. I'll need to just decide on a capacity (40, 42.5 or 44, 47) and design up the internals. Playing around with it some more I'm at 44 gallons with 17 inch clearance minimum. This is empty. My intention is see if I can compensate the weight differential with another leaf so to maintain the clearance. Also, since it's a first I'm certain there will be field adjustments/corrections that I can update, but I'm of course hoping it will be good enough use with those. BTW I have a 2.5" lift.

Thanks for the reply and looking forward to seeing what other input they group might have.
 
since you are going from scratch.. have you thought of doing an LRT and installing it on the front of the rear axle.. as supposed to behind it where the stock tank is ? Having that much weight on the rear limits your load weight and makes your rig squat significantly more....

Just a thought......
 
similarly to an auxiliary tank? Only half the side longwise is availalble for that and I've been wondering would the added weight there cause the car to sag one side. On mine I have an air reservoir there as well for the on board compressor. Although I could very well shift that around if needed.

The LRT will replace the OEM, so approximately 20 gallons more at 7 lbs a gallon, is an additional 140 in the rear. I need talk to the leaf spring guy and get his feedback if added springs would offset the sag. What's the clearance on yours? I believe you purchased one from out there? Thanks for the input.
 
similar in a way that it sits as a saddle and across the frame. kind of like a horse shoe shape......
This means relocating your muffler and your air tank..

I never had a LRT on my rig when I had spring leafs, but when loaded I used to sag with heavy OME's..
Given I probably was taking too much crap back then and I ended up putting airbag over the axle to the frame.. that took care of the problem....

Im running coil springs and have a set of Heavy progressive springs to deal with the extra fuel, drawers, rear 4+ bumper with spare tire and two bikes... the thing does not sag, it actually rides smoother, but I can feel the weight on the rear...

If I was to do it all over again.. I would def try to design a fuel tank that sits on the front of the rear axle and along the drive shaft on both the driver and passenger sides... then I would put the muffler under the rear cargo area along with any other gear that can sit there....
This would deal with the sag and clearance issues......
 
It's worth noting that we drag the spare tire often when left below the OEM tank. Sometimes hard enough to damage the rim. The profile you design should be significantly higher. Creasing in a leak on a 45 gallon fuel tank would really ruin everyone's day.

I'm with Manuchao that a saddle tank would be my first choice.
 
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Hi guys, I've got two approximate designs going on here. I was curious to feedback/suggestions on minimum clearances from the ground.

Currently I am 17 inches from the front leading edge and about 20.5 from the rear edge to the ground; upward slope of 3.5 inches front to back. My mockup you can't even see the tank from standing behind it. It's approximately 42 gallons and every inch I increase it increases the capacity around 3.5 gallons. I.e., if I have capacity of 46 gallons, I'm 16 and 19.5 inches of clearance, front and rear of tank respectively.

On design two I have the leading edge parallel to the ground (for 14 inches toward the rear) at a height 17 inches off the ground and then a slightly greater departure angle to give 21.5 inches clearance. Adding an inch to the tank as above (reducing clearance by and inch: 16 & 20.5") will add around 2.5 gallons of fuel and lower as above.

If I can figure out how to attach some photos I'll do that later. Simply put however, what min clearances is suggested for moderate off roading/overlanding? I may try this in one of the other forums too, but would prefer to continue this one. Thx!

PS. Fred thanks for all the patience and help!

I like how you are doing this. The tanks in Australia are 190l / 50 US gal. They are designed to come even with the bottom of the rear receiver hitch. That is why I left my hitch on my truck. I'd sure be interested in a tank that would be close to that. So if you are around 46 gal,
then you have a good long range tank. Instead of a square rear corner along the whole width, you cut a champher of 4-5" I bet it would
reduce ground strikes by a fair bit. Good luck with this, BTW, I need one by Sept! ;)
 
Cruiserpilot, When you say "even with the rear hitch" do mean that the bottom of the tank from front to rear is inline with the receiver hitch? My tank sits lower than my hitch receiver in the front, however does have a departure angle so that it sits near or slight above the hitch inside the frame crossmember. I believe this is similar to the chamfer you're mentioning above.

Juggernaught, I was under a stock with tire 60 series the other night, and it clear about 12 inches. As mentioned before, I'm hoping for some feedback from guys that do some decent offroading, but with my lift, empty tank, I'm at 17 inches at front and 21.5 in the rear, inline with the bottom of the receiver. I did forget to mention I will also bend a 13 gauge carbon steel or so skid plate that will offset the profile of mine by a quarter of an inch. I'll most like use rubber or something to gap the skid plate from the tank. I also hope to reinforce the bends with 1/8 plate and the other areas are to receive some beading for rigidity to hopefully eliminate "popping" noise some gas expansion may cause.

Manuchao, I crawled under the vehicle because I like your idea of the "horseshoe" type tank. Someone else I know mentioned airbags underneath and I think it's a good way to go. Can you pm me some info on your setup please? I know nothing about them In my vehicle I have 5"s of travel to my axle bumpers. Accounting for that chance the auxiliary tank would really be reduced in volume considerably, unless I use a shallow crossover tube b/n tanks... I look again tomorrow. I like the idea for water storage too.

Thanks Guys!

I just saw the obvious attach file button. The attached diagram is really basic. The green outline is around 40 gall. The black outline is the second design giving me a little more volume, however keeps my clearance at 17 inches longer before the departure angle starts. Seems kind of anticlimactic however the detailing/learning s/w seems to take a long time. Will start detailing baffle and bracket design this week.
 

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I like that larger profile. If the rear of the tank is higher than the bottom of the crossmember of receiver hitch, then
I like it. What is your calculated volume of that larger tank?
 
It's about 43 gallons. If I drop the the horizontal an inch it adds another 3 gallons so, 46. Allow some for some margins of plus or minus .5 gallons. It's all on the computer right now so who knows what the field fixes with bring.

The mock is about an inch deeper than the design above. It's sitting in there crooked because it's only being held in there by one bolt in the front and two weak brackets in the rear. The second picture is just a profile shot. I'm squatted down to take it.

How should I listing these photos by the way? I see some guys do links, other inserts. design 1 mockup underneath.jpg design 1 rear view.jpg
 
I talked to Al at Man-a-fre. He can still build . The design is the same as Long Range with a one added change. Extra baffling for fuel injection.
The problem is he is hesitant to spring for them because a minimum run is 5. In the past 5 was a two
year supply. If you are serious about buying these, email him. There is about a two to three week wait
once he places the order.
He sprung for the FJ40 rear aux tanks at the end of last year. He had seventeen interested , 8 said they were certain. Only one actually followed through. That tank is an aluminum tank with extensive baffling, dual sender patterns, skid plate and a spill resistant filler design of my suggestion.
 
Thanks for the heads up. From his website his fj40 tanks are a real beauty. I imagine the 60s would be as well.
 
Or one of these...View attachment 967126
I imported this from AU. It's made by Brown, holds about 17 gallons and they are still made. I made a dual filler from the stock fuel fill and have a valve to switch between tanks. Spare stays under the stock tank and I have about 42 gallons of fuel.

A guy on mud was considering making a batch of these a while back?

Another idea.

A saddle is the best option IMHO, but not a horseshoe shaped one.

The available room in the area a saddle mounts, has the driveshaft. AS the suspension moves upward, so does the DS, which would not leave much room for the top of the horseshoe. Plus, there is no real useable room on the DS offset side, between the DS and frame to have much tank.

As far as having a saddle tank be balanced on the CG, look at the picture of mine. The inner side of the tank is at the CL of the frame, and being that the whole tank is between the frame CL, it is close to be balanced and is not really noticed, full or empty.

And for me, I have 33/9.50-15 spare in the stock position and like it, plus I have 2 separate tanks.

My 2$ worth.
 

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