Build your own fuel tank?

[Coffee Freak]

Has anyone built their own fuel tank? If so, what tech is needed (assuming carburated)? Are there any inspection "gotcha's" to watch out for?

Here's what I'm hoping to do with mine:

Since I'm starting out with a military m38a1 tub, I'd like to use a jerry can mounted to the back and use a fitting like this: http://www.jegs.com/i/JEGS+Performance+Products/555/100560/10002/-1
on the bottom to run connect the fuel line to. I know I'll need a vent as well, so I'm assuming one like it at the top as a return vent.

Is it that simple? Am I missing something? I like simple, but it usually becomes WAY more complex than my simple mind and lack of skills allows.

 

[sgtpontiac]

Incorporate a roll over valve as well....

Has anyone built their own fuel tank? If so, what tech is needed (assuming carburated)? Are there any inspection "gotcha's" to watch out for?

Here's what I'm hoping to do with mine:

Since I'm starting out with a military m38a1 tub, I'd like to use a jerry can mounted to the back and use a fitting like this: http://www.jegs.com/i/JEGS+Performance+Products/555/100560/10002/-1
on the bottom to run connect the fuel line to. I know I'll need a vent as well, so I'm assuming one like it at the top as a return vent.

Is it that simple? Am I missing something? I like simple, but it usually becomes WAY more complex than my simple mind and lack of skills allows.

usually you can find a vent valve that acts as a roll over valve too.....I believe in the kiss method of stuff when possible.....

 

[Tude]

Make sure at the bottom of the pickup tube you have a screen.

 

[Old Iron]

Pretty much that simple

 

[Coffee Freak]

Pretty much that simple

Perhaps I'm overthinking this, but I've seen two different schools of thought on where to put the fitting for the fuel supply. One is to drill into the bottom and attach it like a sump (think motorcycle tank) and the other is to weld in a long pipe nipple from the top down so that the bottom of the pipe is near the bottom of the tank. This way, the tank could sit on a flat surface (think boat fuel tank).

Is there any benefit to one method over the other aside from the placement of the tank? I could pretty easily suspend the Jerry can from a bracket so that it still "looks" like it's there as a spare gas can. Would this "gravity feed" work in conjunction with a fuel pump, or would it continuously syphon gas into the carb? I know more about fuel injection than I do carburators, and even that isn't as much as I need to know.

 

[sgtpontiac]

If I'm readiing this right...

Perhaps I'm overthinking this, but I've seen two different schools of thought on where to put the fitting for the fuel supply. One is to drill into the bottom and attach it like a sump (think motorcycle tank) and the other is to weld in a long pipe nipple from the top down so that the bottom of the pipe is near the bottom of the tank. This way, the tank could sit on a flat surface (think boat fuel tank).

Is there any benefit to one method over the other aside from the placement of the tank? I could pretty easily suspend the Jerry can from a bracket so that it still "looks" like it's there as a spare gas can. Would this "gravity feed" work in conjunction with a fuel pump, or would it continuously syphon gas into the carb? I know more about fuel injection than I do carburators, and even that isn't as much as I need to know.

probably less chance of sucking air if the pickup was on the bottom than the tube idea....as for the gravity feed to the pump...yes...the fuel pump should be gravity fed....lower than the tank....they don't like sucking air / priming......

 

[zzrodder]

I've built 10+ tanks and have always incorporated the same features - baffles to control fuel slosh, a separate vent plumbed to the air cleaner or a charcoal canister, and the pickup line coming in from the top.
I like to try to head off problems before they happen and to my mind, with the line coming off the bottom of the tank, there is always the chance of a leak, broken line or fitting, then the entire contents could drain out - at the worst time of course.....
Usually I either run the pickup tube to the bottom of the tank with notches cut in the end so it won't suck up against the bottom or sometimes curve it so it lays sideways on the bottom and weld it to the bottom and use a separate external filter.

 

[Old Iron]

I've always welded a bung in the front, back or sides of the tank, right against the bottom for pickup.
If you're worried about a leak then, the tube from the top to the bottom is the best choice with a vent in the top.

 

[sgtpontiac]

I agree.....

I've built 10+ tanks and have always incorporated the same features - baffles to control fuel slosh, a separate vent plumbed to the air cleaner or a charcoal canister, and the pickup line coming in from the top.
I like to try to head off problems before they happen and to my mind, with the line coming off the bottom of the tank, there is always the chance of a leak, broken line or fitting, then the entire contents could drain out - at the worst time of course.....
Usually I either run the pickup tube to the bottom of the tank with notches cut in the end so it won't suck up against the bottom or sometimes curve it so it lays sideways on the bottom and weld it to the bottom and use a separate external filter.

but it didn't look like he was going to have baffles or some of the features that might be a better design, so thought the bottom pickup was better in his case...considering the size of the jerrycan.......JMHO...

 

[Torch]

any air that gets in your lines for whatever reason is going to get pumped to the carb then go right out the vent.
the mechanical fuel pump in my chevy has a return to the tank and when it sits some of the fuel in the line bleeds back into the tank as air is supplied to the pump via the return.
So if it sits long enough it has to prime itself then pump out all the air.|
I have an electromagnetic solenoid disc type electric fuel pump (not a rotating vane type) above the fuel tank on the continental f162 in my forklift to replace the mechanical.
If it sits long enough I have to pull off the hose and drip a little gas down into the pump to manually prime it...
But not that it wont pump air. it will pump air but it needs to be WET to do it.

I like the idea of not having the risk of scraping something off the bottom of the tank and getting an epic leak.
|

 

[Coffee Freak]

but it didn't look like he was going to have baffles or some of the features that might be a better design, so thought the bottom pickup was better in his case...considering the size of the jerrycan.......JMHO...

Yeah, 5 gallons shouldn't have mush slosh, so baffles shouldn;t be an issue. For me, the bung at the bottom would be better aesthetically since I could hide it easier, but I think I like the functionality of the top down better.

 

[jmlcolorado]

Here's my rendition of a tank. My pickup is on the top front side. Drops down into a smal sump. I also have a bung on the bottom of the sump for draining if need be (or so the locals can steal my fuel easier when gas prices are high ). Also have a bung on the top for a vent.
I did baffles in mine. Totals 23 gallons.

 

[Torch]

... I forgot to mention... if you have a pinhole or some kinda leak on the suction side of the pump...
It's going to forever suck in air

 

[sgtpontiac]

jmlcolorado....now your just showing off..lol

baffles and sump are always a great thing....just not sure that you could do much with the can he is going to use....unless you wanted to split it and such...but a lot of work for 5 or 6 gallons....I like the 23 gallon size myself....nice work by the way....