Permanent reserve fuel tank

[TunaCrazy]

My brother and I bought a 1977 Luhrs 320 Flybridge. Love the boat, love the 454ci Crusaders in it, but not so fond of the 140 gallon fuel capacity (two 70 gal). There is a ton of room below the deck in the cabin to mount an additional fuel tank. Anybody done this before? Any tips on plumbing? Would you suggest a pump to refresh the main tanks, or plumb it so both engines could run directly off the reserve tank? Run a REALLY LONG, REALLY expensive fill neck down to it? Or again, use a pump and just transfer fuel when needed?

Trying to plan this out and see if it is a feasible project.

Thanks in advance!
Eric

 

[Chris1956]

Re: Permanent reserve fuel tank

Can you replace your 70gal tanks with 100 or 150 gal tanks? That would be easiest. If that doesn't work, it would be best to add a large single tank, likely somewhere int he center of the hull. You would need valves to connect each motor to the new tank, and two independent 3/8" fuel pickups on the tank.

Adding a fill capability is the easiest, since it is just a thru hull fuel filler and some 1 - 1/2" fuel hose, plus gravity. You could plumb the fuel tank vents together if convenient.

 

[Beefer]

Re: Permanent reserve fuel tank

I know the title says 'Permanent', but what about a fuel bladder for the times you're making the longer runs? Easier to install, and can be removed when not needed. Just a thought.

 

[sasto]

Re: Permanent reserve fuel tank

A fuel transfer pump would be my first choice.

 

[TunaCrazy]

Re: Permanent reserve fuel tank

Replacing the tanks would be a HUGE project. The cockpit floor would either need cut, or the engines yanked to replace the original tanks.

When I said "permanent" I only meant "installed". Not a Jerry Can rack or anything like that. As for a bladder, that could work, but where would the bladder be placed? I do not want to use any of my precious top-side space, and we have plenty of room under the cabin deck. If we are installing below-decks, may as well go with a polyethylene tank (permanent). I found a 52 gallon Moeller tank that is only 10" tall and would fit perfectly with a couple inches to spare:

http://www.iboats.com/52-Gallon-OEM...3036996--**********.448193690--view_id.483873

It seems a transfer pump would be the easiest route for installation. Not quite the easiest to "use" per se, but installation would be much easier (fill main tanks, transfer to reserve, top off main tanks). That way, only one vent hose and one transfer hose would be needed. We would not have to run any insanely-expensive $1.25-per-INCH fill hose.

Does this sound like a feasible plan? Any suggestions on a high-volume pump?

 

[sasto]

Re: Permanent reserve fuel tank

That would require a 2-way pump. I can't help on your pump selection, I have 2 of them made by Groco....they are for diesel. They may make one for gas. Good luck, Eric

 

[Frank Acampora]

Re: Permanent reserve fuel tank

You would need an insanely expensive racing pump otherwise it will take forever to transfer 52 gallons. No code says that the fill must be ALL hose. However any hose used must be grounded. Use aluminum pipe or other metal pipe of choice coupled with the expensive (grounded) marine fill hose at the connections to run the fill tube.

 

[TunaCrazy]

Re: Permanent reserve fuel tank

You would need an insanely expensive racing pump otherwise it will take forever to transfer 52 gallons. No code says that the fill must be ALL hose. However any hose used must be grounded. Use aluminum pipe or other metal pipe of choice coupled with the expensive (grounded) marine fill hose at the connections to run the fill tube.

Good idea on the fill pipe. If I ran the fill like this, it would be cheaper, and I would only need one transfer pump. How about something like this, and just remove the nozzle that comes on it? 20GPM seems sufficient, and $145 is not terribly bad. Looked briefly and cannot seem to find one of these pumps without the nozzle. I can look more later.
http://cgi.ebay.com/20-GPM-12V-Heav...035?pt=LH_DefaultDomain_0&hash=item2eb0b78ddb

 

[Chris1956]

Re: Permanent reserve fuel tank

You are making this too hard. A fuel transfer pump is too complicated for what you want. You can buy 112 feet of rubber fill hose for the same price as the fuel transfer pump.

Find a place for the reserve tank. Find a way to route that rubber fill hose. Find a way to route the vent and fuel pickups. Buy 2 two-way selector fuel valves, and connect everything up. Only fill the reserve tank when you need it.

Is 52 gal reserve fuel enough? On the east coast, the canyon is 70-100 miles offshore. a cruiser like yours would need 300+ gal to get out, back and have 1/3 in reserve.

 

[TunaCrazy]

Re: Permanent reserve fuel tank

You can buy 112 feet of rubber fill hose for the same price as the fuel transfer pump.

Actually, it would get us less than 112 *INCHES. Unless you know of somewhere to get the hose cheaper? I just recently had to buy 60 inches (5 feet) to replace the crap that came on the boat (see attached), and it cost us $85. It was actually more like $1.40 an inch. If I only had to do 10 feet, it would cost ~$168 just for the fill hose alone, but I have a feeling it would require more like 15 feet. Don't get me wrong, I would rather NOT have to deal with a transfer pump. I would much rather just switch the valves and go, as you said, but my funds are unfortunately pretty limited at the moment.

There is also a 90 gallon version of the same style tank, but I am not sure if we have enough room for that one (length-wise). An additional 90 gallons would give us 230 total; which would certainly be nice, but the 52 would give us 192 gallons, and our furthest-planned trip is to San Clemente Island at 60 miles one way. I will shoot for the 90, but 52 should be plenty.

 

[Chris1956]

Re: Permanent reserve fuel tank

1-1/2" Marine fuel filler hose is available for cheaper that you found. A quick search showed 10' for $63.56, which is still outrageous. it should be available cheaper.

Wiring a fuel transfer pump will be a drag, and won't work as well as going the simple way of having a standalone reserve tank with a dedicated fill hose. You will spend much time at the gas pump filling the main tank, with the transfer pump running and waiting for it to pump up the reserve tank.

 

[dingbat]

Re: Permanent reserve fuel tank

It seems a transfer pump would be the easiest route for installation. Not quite the easiest to "use" per se, but installation would be much easier (fill main tanks, transfer to reserve, top off main tanks). That way, only one vent hose and one transfer hose would be needed. We would not have to run any insanely-expensive $1.25-per-INCH fill hose.

Does this sound like a feasible plan? Any suggestions on a high-volume pump?

You where robbed. The going price for Trident 1 1/2 Marine Fill Hose. USCG Type A2, SAE J1527 is $6-$10 per foot ($0.50-$0.84 per inch).