I'm working on a taildragger aux fuel tank for my GL1800 that will hold the tank much closer and slightly higher than most taildragger setups (click to enlarge).
While the tank has a vent on the fill neck, I've been wondering if I should concern myself with an overflow tank. I know that gasoline expands roughly 1% for every 15 degrees of temperature increase, so with a tank capacity of 4.25 gallons that equates to just under 6 ounces in potential expansion for every 15 degrees. I'm also aware that I don't want fuel just sloshing out the vent hose onto the ground (if I had it all to do over again, I'd have opted for a fill neck several inches longer, but it is what it is).
So the way I see it, I have two options:
1) Don't fill the tank to 100% capacity, and route the vent line up several inches before routing it back down toward the ground (routing it up first would help slow down any sloshing out before it spilled onto the ground). Call it "good enough" and hit the road.
2) Weld a 2x2x3" expansion tank on the side and attach the appropriate plumbing to make it an overflow/vent tank. That would be a capacity of approximately 6 oz., so if I wanted some extra buffer I could simply make it 6" long for a total capacity of roughly 12 oz. Alternatively, I could attach the overflow/vent tank to the base of my trailer hitch and leave the tank unmolested - just attach the vent line to the tank.
I may be making much ado about nothing, so I'd like the input of people here who have experience with aux tanks.
(Bonus question: Anyone have any bright ideas for how to attach a license plate to a cylindrical tank?)
While the tank has a vent on the fill neck, I've been wondering if I should concern myself with an overflow tank. I know that gasoline expands roughly 1% for every 15 degrees of temperature increase, so with a tank capacity of 4.25 gallons that equates to just under 6 ounces in potential expansion for every 15 degrees. I'm also aware that I don't want fuel just sloshing out the vent hose onto the ground (if I had it all to do over again, I'd have opted for a fill neck several inches longer, but it is what it is).
So the way I see it, I have two options:
1) Don't fill the tank to 100% capacity, and route the vent line up several inches before routing it back down toward the ground (routing it up first would help slow down any sloshing out before it spilled onto the ground). Call it "good enough" and hit the road.
2) Weld a 2x2x3" expansion tank on the side and attach the appropriate plumbing to make it an overflow/vent tank. That would be a capacity of approximately 6 oz., so if I wanted some extra buffer I could simply make it 6" long for a total capacity of roughly 12 oz. Alternatively, I could attach the overflow/vent tank to the base of my trailer hitch and leave the tank unmolested - just attach the vent line to the tank.
I may be making much ado about nothing, so I'd like the input of people here who have experience with aux tanks.
(Bonus question: Anyone have any bright ideas for how to attach a license plate to a cylindrical tank?)