Custom 35 gallon gas tank for '09 Tacoma
- Thread starter cwvandy
- Start date
Dave Bennett
Adventurist
Desert Dan
Explorer
Looks good.
add a leaf
The fuel alone should weigh about 250-280lbs.
add a leaf
The fuel alone should weigh about 250-280lbs.
Thanks Dan. I know Bend is out of the way, but the guys at Custom Exhaust Specialties do fantastic work so I highly recommend them for almost any custom metal work. They have several frame-up restorations in process on some vintage 4x4 rigs. Beautiful stuff.
If I get a total of 37 gallons all the gas will weigh about 225 lbs. My 100 lbs +/- figure was for the additional gas over stock (about 15-17 gallons at 6.073 lbs per gallon). The skid plate is bigger and the new tank is bigger AND 16 gauge steel, however, rather than plastic, so may may be close on the total additional weight #. I will weigh the pieces before they are installed and see what I am dealing with. Fortunately I have already have added another leaf to the standard Taco Dakar spring set-up (I often tow and a Horizon trailer). Do you know if I can add another one if necessary??
If I get a total of 37 gallons all the gas will weigh about 225 lbs. My 100 lbs +/- figure was for the additional gas over stock (about 15-17 gallons at 6.073 lbs per gallon). The skid plate is bigger and the new tank is bigger AND 16 gauge steel, however, rather than plastic, so may may be close on the total additional weight #. I will weigh the pieces before they are installed and see what I am dealing with. Fortunately I have already have added another leaf to the standard Taco Dakar spring set-up (I often tow and a Horizon trailer). Do you know if I can add another one if necessary??
Dave Bennett
Adventurist
You could but you may need different/larger spring clamps and u-bolts. I've thought of doing that myself vice having custom springs made
TangoBlue
American Adventurist
Agreed, and perhaps a new center-pin. My only concern is how well matched the leaves would be for weight bearing and suspension.
At least the options are clear cut... add-a-leaf or custom springs. But that's a bridge you'll cross when you get the tank installed, filled, and a test drive.
At least the options are clear cut... add-a-leaf or custom springs. But that's a bridge you'll cross when you get the tank installed, filled, and a test drive.
frozenground
Adventurer
wow, subscribed :costumed-smiley-007
Is the tank 14ga or 16ga? You quoted both in different places. Either way, the weight of the tank alone will be significant. I have built a few custom tas tanks in this manner and the weight at first was a big surprise. I wouldn't be surprised if the total weight of the tank and gas wasn't 300#. You'll need to have some pretty substantial supports to keep the tank under the truck over rough terrain. Definitely comprehend that early in the build because you may need some structure built into the tank to facilitate mounting. You will also have a 225# gradient of weight from full to empty acting on one side of the truck. No real way to compensate that unless you use some sort of overload system like an airbump that only comes into play when the tank is heavy. Any attempt to compensate with springs or airbags will result in an oversprung condition as the tank drains.
Also, it appears you have created high points that will trap air. If that is the case, you won't be able to fill the volume very effectively. Some of the space and weight created may not be usable.
Welds on a gas tank are the biggest liability and the greatest potential for leaks. Minimizing welds is always a good strategy, but this tank has a ton of welds. Using a semi-formed bottom peice was a smart move! Be extremely careful about weld quality and definitely pressure test the tank before use.
Lastly, tanks with large flat bottoms can be a problem at low fuel levels. Several gallons of gas can shift into areas where the pickup cannot reach when operating over unlevel ground. Even accellerating and braking can result in momentary starvation. It is usually best to have some sort of sump with a slight taper into it. You can also minimize short term starvation with a carefully designed baffle system. The baffles can be passive or active, utilizing one way valves as simple as little swinging gates. The gates can allow gas into the pickup chamber but resist the flow out. The baffling should not extend too high because if it does it will interfere with filling. These are things you can't go back later and fix, so they must be well tested before the top is welded on.
It looks like your build quality is very high, and I'm impressed with that! Please understand, I'm not trying to rain on youir parade with these suggestions. I've just been way down this trail and gotten my boots muddy along the way :sombrero: Just trying to help you succeed, not criticize! :ylsmoke:
Also, it appears you have created high points that will trap air. If that is the case, you won't be able to fill the volume very effectively. Some of the space and weight created may not be usable.
Welds on a gas tank are the biggest liability and the greatest potential for leaks. Minimizing welds is always a good strategy, but this tank has a ton of welds. Using a semi-formed bottom peice was a smart move! Be extremely careful about weld quality and definitely pressure test the tank before use.
Lastly, tanks with large flat bottoms can be a problem at low fuel levels. Several gallons of gas can shift into areas where the pickup cannot reach when operating over unlevel ground. Even accellerating and braking can result in momentary starvation. It is usually best to have some sort of sump with a slight taper into it. You can also minimize short term starvation with a carefully designed baffle system. The baffles can be passive or active, utilizing one way valves as simple as little swinging gates. The gates can allow gas into the pickup chamber but resist the flow out. The baffling should not extend too high because if it does it will interfere with filling. These are things you can't go back later and fix, so they must be well tested before the top is welded on.
It looks like your build quality is very high, and I'm impressed with that! Please understand, I'm not trying to rain on youir parade with these suggestions. I've just been way down this trail and gotten my boots muddy along the way :sombrero: Just trying to help you succeed, not criticize! :ylsmoke:
Sorry. My bad. The gauge is 14. We picked up the partially finished tank as it appeared in the last picture (probably about 80% completed?) and I guess it was short of 50 lbs. It was only tacked together and finished welds and additional pieces & baffles will surely add some more weight. We intend to put in 4 baffles which will increase weight but reduce the inevitable sloshing around. These guys have built dozens of tanks so I am relying on what the right # of baffles will be for this size tank. As to final weight, I don't think 300 is far off, a bit more than double the weight of the full stock tank. I think you are spot on that we will not be able to fill every bit of the entire tank because of the shape. Just have to wait and see how much we can use and what happens on long ascents/descents with a low fuel level. I ran into issues in this regard even with the stock tank.
Hear ya' on the pressure testing. It is on the list and we plan to put in significant pressure, meter it, wait and make sure it is tight. Really don't want to get this puppy powder coated and find that a weld is bad. And I appreciate the feedback and experienced-based words of advice. I wanted to share this project, but I also hoped that folks would jump in with their experiences and ideas. Thanks for taking the time!
Hear ya' on the pressure testing. It is on the list and we plan to put in significant pressure, meter it, wait and make sure it is tight. Really don't want to get this puppy powder coated and find that a weld is bad. And I appreciate the feedback and experienced-based words of advice. I wanted to share this project, but I also hoped that folks would jump in with their experiences and ideas. Thanks for taking the time!
TangoBlue
American Adventurist
Great observations, not just for this project, but your contribution to all of us. Thanks!
It's an awesome project! I'll bet I can guess what you are spending to develop this too. This kind of work don't come cheap. One more suggestion that will likely save you some trouble. Size the end pieces so they fit inside the formed bottom instead of flush with the edge. They should be about 1/4" in. The reason I say this is because then you can lay a fillet weld into the corner it creates. Does that makes sense? That will make the connection super strong, provide less chance for leaks, and create a very strong tub. The welds on the top don't take nearly the stress that the ones on the sides do. Creating an opportunity for a fillet weld will make it bombproof.
If you need any special services in the Bend area let me know! I have alot of contacts there. Bill Nye, who owns Commercial Powdercoating in Bend does excellent work.
Best of luck!
achampagne
Explorer
subscribed, great project!
Jeff Wanamog
Off Road Camper Guy
Why don't you let me help you pay for some of those R&D costs.
I would pay big bucks for this off road only gas tank that would never be used on the highways of California.
I would sign anything and pay big bucks.
I share your pain my friend.
Kudos to your drive to make you rig better.
Will you have to link the high points to vent it?
P.S. I am serious about the money thing.
PM me.
Jeff
I would pay big bucks for this off road only gas tank that would never be used on the highways of California.
I would sign anything and pay big bucks.
I share your pain my friend.
Kudos to your drive to make you rig better.
Will you have to link the high points to vent it?
P.S. I am serious about the money thing.
PM me.
Jeff
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