fuel tank ;

[jerry1865]

hi, im making an aluminum fuel tank and im seriously thinking of putting the outlet on the side down at the bottom of the tank. i know that most tanks have the outlet out of the top.
is there a reason for that?
if it matters, im running a holley red pump on a v8 300 jonny and she likes about 35 gallons an hour....lol

 

[Chris1956]

Re: fuel tank ;

Most tanks have a top fuel pickup for two reasons. Firstly, any dirt or water will settle to the bottom of the tank. The top mounted pickups do not reach all the way to the bottom so they do not suck up this stuff. Secondly, sometimes you need to remove the fuel pickup to clean the screen or antisiphon valve. This is a lot easier from the top.

BTW - An bottom outlet on a marine gas tank may not be code, since the potential for the fuel line to break and all the gas to go into the bilge and explode.

 

[jerry1865]

Re: fuel tank ;

thx for the info. makes good sense. i will put it in the top ,jerry

 

[dontask]

Re: fuel tank ;

Most tanks have a top fuel pickup for two reasons. Firstly, any dirt or water will settle to the bottom of the tank. The top mounted pickups do not reach all the way to the bottom so they do not suck up this stuff. Secondly, sometimes you need to remove the fuel pickup to clean the screen or antisiphon valve. This is a lot easier from the top.

BTW - An bottom outlet on a marine gas tank may not be code, since the potential for the fuel line to break and all the gas to go into the bilge and explode.

You do want the pick up tube to be far enough down to pick up debris and move it to the filter assembly. If water is allowed to sit in the bottom of your metal tank it will start to corrode or rust that tank. Secondly slant the pick up tube at the very end will keep it from being blocked by the tanks bottom surface. The tube should not touch the bottom of the tank as to wear through the tanks wall from continual flexing during verticle loads/stresses.

 

[Silvertip]

Re: fuel tank ;

I'm not familiar with the fuel pump you mentioned but I assume it's electric. Unless you have a way to kill that pump if the engine dies, you have the possibility of a serious problem. You can load the engine with fuel and when you hit the key it will go kaboom, or the engine will be hydrolocked. If you spring a leak somewhere along the line that will also create an issue. Fire is a nightmare on a boat and unless the pump quits when the engine dies, it will continue to feed the fire until power is cut or everyone is toast and it will no longer matter. EFI/DFI engines use the ECU to tell the pump to turn off if sees zero RPM. You don't have that capability on a carbed engine. Pulling the kill switch lanyard will not kill an electric pump and I would bet in case of fire due to a dead engine or fuel system malfunction the last thing you would remember is to turn the key off to kill the pump. If I have mistaken the pump design, this is all moot.

 

[Mark42]

Re: fuel tank ;

The fuel line MUST come off the top of the tank to be legal as per Coast Guard Regulation:

183.518 - Fuel tank openings: Each opening into the fuel tank must be at or above the topmost surface of the tank.

Fuel tank openings refer to holes into which fittings may be installed or fuel lines attached. Fuel tank fill, fuel tank vent, fuel distribution, fuel tank sounding, and fuel level sender fitting accesses are examples of such openings. If the attachment fitting is welded or attached by other non-removable means to the fuel tank, the opening is considered at the top of the attachment. The sketches below clarify this interpretation.

 

[gss036]

Re: fuel tank ;

I just had a new tank installed and had to cut the old tank apart so got a good look inside with the baffles about 25 inches apart and the twin pick up tube about 3/16th inch off the bottom with ^ groove at the end of the tube. The 115 gallon tank weighed 125 lbs. You need a ground lug on the tank in addition to the ground lug on the fuel sender.
Also consider how you will mount it on/in the boat and securing it.

 

[P 0 P E Y E]

Re: fuel tank ;

Good Copy