Fuel tank placement question

[Q_ball]

I have a 14' tri-hull that i am restoring and found a fuel tank for a great price and it will fit under the splash well. tank is 47"L X 18"W X 8"D under deck style with the fittings at one end.
If I mount it this way will i have problems when turning to the opposite side of the fittings, if so what can i do? or should i go with something else?

 

[oops!]

Re: Fuel tank placement question

HI Q BALL....WELCOME TO I BOATS

i dont really understand the question !!!! can u please rephrase?

thanks

 

[pete44]

Re: Fuel tank placement question

If the fittings you are talking about are for the vent,gas filler and fuel line it should not make a difference.I am assuming the lines are on the "opposite side" in relation to the tank?..I also have a 20 gallon "belly tank" in my bowrider with a screwed in "access hatch"...The vent and filler lines are on starboard side and the fuel line to pump on port side..

Pete

 

[Q_ball]

Re: Fuel tank placement question

sorry, i didn't explain very well at all. it is a belly tank with fill, vent, fuel supply all at one end. normally would go between the stringers with the fittings at the rear of the boat. i'm turning the tank sideways so it would be the full width of the deck under the splashwell with fill, vent and fuel line on the port side.

 

[Q_ball]

Re: Fuel tank placement question

here is another pic of the tank in the boat. if i turn the boat left the fuel will move towards the fittings, but turning right the fuel would flow away from the fittings and suck air instead of fuel. am I correct with this assumption?

 

[erikgreen]

Re: Fuel tank placement question

Yes. I'm doing the same sort of mounting with my tank, and I'm going to plan to mount the tank tilted toward the side with the filler, so it's mostly leaning that way.

Ideally I'll replace the tank with one that's got a V bottom or a low center point, so no matter which way I tilt some fuel will flow to the outlet.

If you're mounting a long tank with a flat bottom transverse (across the hull) be prepared to suck air at times.

Erik

 

[Q_ball]

Re: Fuel tank placement question

Thanks "ErikGreen"
do you think 1 1/2-2" higher opposite the filer would be enough?

 

[erikgreen]

Re: Fuel tank placement question

For a 47 inch tank I'd recommend something like 3-4 inches higher. Basically figure out how much the boat could tip to the side away from the outlet on average, and angle the tank to prevent at least some of that from happening.

Note that tilting the tank at all will make your fuel gauge read wrong, and also that I'm only guesstimating the tilt and angle stuff. The fact that mounting a long tank that way doesn't work well is why most people don't do it...

Erik

 

[jspano]

Re: Fuel tank placement question

good question!
here's the problem... tilting the tank will decrease the amount of fuel, since all the fittings are at the low side decreasing the capicity.
doing nothing will suck air when low. i guess you would have to look at how you use the boat... how much fuel do you usually use on an outing, and how much does the tank hold.

i have a 27 gal under bow and a 15 under the splash well and still have to carefull.

 

[Q_ball]

Re: Fuel tank placement question

Good points on the gauge and reduced capacity of the tank, didn't think of those. The boat's only 14' long 64" beam and will only be used for fishing, mainly trolling with long line or downriggerswill the occasional casting deck deck uase. I have a 50hp main and 5hp kicker so i think the 25 gal tank is over kill but for $39.00 plus shipping i couldn't go wrong and having extra capacity will be nice when i hit some of our really big lakes.
Do they have senders that you could adjust. If you set the float to read correctly on the full side and when it droped to the bottom(empty) there would still be some fuel below that point as a "reserve"(maybe a gallon or so?

 

[erikgreen]

Re: Fuel tank placement question

Yes, you can adjust the sender. I'd suspect you'd have more than a gallon of "reserve".. probably more like 10 you can't see.

As long as you're not sucking air with the pickup you can just use a fuel flow gauge and ignore the old E...F one.

Erik

 

[Q_ball]

Re: Fuel tank placement question

Never heard of the flow gauge,(I'm a newbe, first boat)looked it up but I think for this project the price would be too high, at least for now. i've never even had it in the water. when i got it there were a few holes in the hull and three feet of snow inside. the wife thinks this is onlyy going to cost around $1000.00 including the purchase price. i'm not going to tell her the real cost, as you all know restoration are not cheap.

 

[Spinnaker]

Re: Fuel tank placement question

What you could do is take the tank to an aluminum fabricator that has tank experience and have a sump installed at one end of the tank. It doesn't have to be deep, just a couple inches. Problem solved! I say why Micky Mouse things when you can do it properly.

 

[Q_ball]

Re: Fuel tank placement question

The problem is the tank is plastic. I wouldn't think modifing a plastic tank would be a good idea.

 

[Fisherball]

Re: Fuel tank placement question

I had a long tank mounted the same way. Never had a problem in a 15' '61 Larson with 70 hp. Boat would go 35 & it never even sputtered when making sharp turns. The gauge was a sight gauge with a hole cut in splashwell above it. Don't let your tank get too empty. Can't you just the turn the tank around so the fittings are on same side as needed?

 

[Spinnaker]

Re: Fuel tank placement question

The problem is the tank is plastic. I wouldn't think modifing a plastic tank would be a good idea.

Ok. Thought it was aluminum. Anyway, I should have mentioned this in the first place, just install a fuel/water filter kit. The filter will always ensure constant fuel. It's an application I've used many times for starving kickers.