Another Fuel Polishing and Transfer ?

[GDFL]

Here's what I've got:
(4) 83 gal tanks with valves to control each tank flow and return individually.
(1) racor 500
(1) Frantz Diesel fuel filter (lets not debate this item in this thread)

This feeds a Perkins 6.354NA and a 5kw generator. I'm getting ready to have to move the boat 1500 miles about a month and a half from now. My budget is limited. The Frantz filter is not plumbed in yet. For the sake of this thread, let's all pretend that it works perfectly and there is nothing to debate about its use. I'd like to add a Walbro pump or similar into the system. My goal is to be able to polish fuel, transfer between tanks, prime the filters and lines, and also backup the lift pump in case of failure. I'm completely open to design layout opinions.

I'm guessing the Racor should go downstream of the Frantz. Should the pump be on a closable loop upstream of the filters? Will the pump work without being filtered or should I buy an inexpensive filter or something to block the pump clogging chunks? I know I've read debate on using the pump to push vs pull fuel and many other aspects of the system. Keeping in mind that I have several other things that I need to spend my limited funds on before the trip, what would YOU do?
Thanks,
Garrett

[never monday]

a Racor 500 must not be pressurized.

I'd skip the Franz, IMHO.

mechanical lift pumps will fail from a ruptured diagram. pressurizing the mechanical pump in this state can fill the engine with fuel

[eyschulman]

There are a lot of unknowns about your tanks and fuel sx. If your tanks are clean and fuel in them is free of crud and water a simple circulating filtration sx may work for you. If your tanks have crude on bottom it will do little good unless there is a high pressure and high flow method of breaking crud lose from bottom of tanks. Only direct access to tank innards and direct cleaning of tank will handle that-old fuel dumped or polished. The simplest way to handle the situation is what the professional fisherman do- They have large tanks and hold fuel for long periods so crud and water in fuel is common. What is commonly done is the use of bulk filter separators of the spin on type. a vacuum gauge is also used to let them know when to spin off clogging filter and spin on new one a relatively fast process- they buy the filers by the box. fleetguard makes several sizes of these bulk fitters- install before racor and use 30 micron on bulk unit 30 or 10 micron on racor. If you really want to do it right install a outboard motor bulb type primer pump in an isolated loop between tanks and filters(read no more bleeding or filling new filters with fuel just pump bulb until fuel and air goes into return line and back to tank then start motor ( its the cats meow)

[Inthewind]

Have you determined the degree of contamination in your tank? Are the filters dirty now and have they clogged up shutting you down. Do you have access into the tanks big enough to physically clean them? If not, can you cut access ports into the tank? If you wanted to devise a polishing system, it would be separate from the fuel system. Basically, you would pump fuel through the frantz and back into the tank while constantly filtering the fuel over and over again until you remove a large degree of contamination. That method would take a lot of time unless you had a large enough pump to circulate the fuel at a fast rate and it would use up a lot of expensive filters if the fuel is real dirty. You still would not have the pressure on the return line to break loose the clinging bacteria to the tank. If you were closer I would give you a real bargain on professional diesel fuel polishing as sometimes this is the best option when other alternatives fail or you can't physically clean out the tank. It all depends on how contaminated your tanks are. A small amount of contamination could possibly be managed with a good makeshift polishing system. Good Luck

[GDFL]

Originally Posted by Inthewind

Have you determined the degree of contamination in your tank? Are the filters dirty now and have they clogged up shutting you down. Do you have access into the tanks big enough to physically clean them? If not, can you cut access ports into the tank? If you wanted to devise a polishing system, it would be separate from the fuel system. Basically, you would pump fuel through the frantz and back into the tank while constantly filtering the fuel over and over again until you remove a large degree of contamination. That method would take a lot of time unless you had a large enough pump to circulate the fuel at a fast rate and it would use up a lot of expensive filters if the fuel is real dirty. You still would not have the pressure on the return line to break loose the clinging bacteria to the tank. If you were closer I would give you a real bargain on professional diesel fuel polishing as sometimes this is the best option when other alternatives fail or you can't physically clean out the tank. It all depends on how contaminated your tanks are. A small amount of contamination could possibly be managed with a good makeshift polishing system. Good Luck

The boat is a 79 and the tanks and engine are both 85. There is less than 6" of vertical clearance above the tanks so a clean out port wouldn't be very practical. With only the Racor, I haven't shut down due to a clogged filter yet. (only about 25 hours). I don't think the fuel is all that dirty, but would like to be prepared and not have issues on my 1500 mile trip since It's a delivery and not leisurely cruise. Would a 35ghp 7psi Walbro rupture the mechanical lift pump diaphragm?

I was doing some more reading and may have come up with a plan. Tell me what's wrong with it. I read that a 35gph 7psi Walbro can provide enough suction to pull fuel through filters. I also remember reading that a Walbro pump turned off acts as a piece of hose and doesn't block flow. What about starting from the tanks I used the Frantz, the Racor, the Walbro pump, and then a valve to return fuel to the tanks BEFORE it reaches the engine. Anything wrong with that? Could the Walbro go in front of the filters instead of behind without worry of clogging?

Thanks for the input.

[easterly]

I bought an electric fuel pump, don't know the brand but it was about 40 GPH @ 6 psi, and ran the pump through a cheap inline filter and back into the tank return hose. I ran this for a couple of hours. Then I threw away the filter and reconnected the regular fuel system. It's a cheap way to polish the fuel. I do it at the start of every season.

[Alan Wheeler]

I think you are trying to make the entire process complicated. Keep it simple.
By the way, I have such a similar set up, it sounded like you were talking about my boat.
As Pat suggested, loose the Frantz.
Lets go back a step or two and look at this. If you can not always trust your fuel supplier, for protection of your tanks, it is good to filter the fuel as it goes in. That reduces tank issues and the need to "scrub" which IMO is a little over the top. Also as Pat said, you must not pressurize the 500 Racor. The pump must and can suck through the filter. But if you use an electrical pump, it is best to bypass the engine lift pump. If a fault develops, it can cause a problem. This is my set up,
I have two tanks and a common line with shut off valve on each tank. The line feeds a Racor 900FG with a 10micron filter and water seperater, which is over kill in size, but I got it cheap at the time. From there, the line splits again with two shut off valves and one goes to the lift pump on the main engine (6.354) and the other goes to a filter and then to my 5KVA genset. The engine lift pump pushes the fuel through two smaller filters before it heads on to the Injector pump.
I get very little in the way of water coming through. I remove anywater when ever I see it and then I remove the entire Racor assembly and clean it once a year to ensure I have no gunge inside it. The system is simple and effective and I can see what is happening with water quantity appearing in the seperator bowl. I have considered fitting an electrical pump, but if I did, I would put in a bypass around the mechanical lift pump. That way if I have a problem with the electrical one, I can bypass back to the mechanical pump.

[stillbuilding]

This seems to be problematic. Having been caught with cruddy fuel issues shortly after delivery, I love the idea of cleaning before it drops into my pristine tanks but I have not been able to find any suitable device which will filter the in-going fuel other than a Racor hand-held funnell which seems a bit mickey mouse of taking on a thousand litres or so at a time. Does anyone have a nice solution for this?

[AnchorageGuy]

We have been using a Baha filter for years. It slows down the filling process a bit but since we started we have had zero issues with dirty fuel.

[DeepFrz]

There really isn't anything suitable for filtering when taking on 1000 liters at a time, as far as I know. A Baja filter will take forever.

If you have large tanks then I believe that polishing is the only way to keep your fuel and tank in good shape between tank cleanings.

A good fuel polisher should be able to filter the volume of your tank in about 3 hrs. or less (I think 100 gals. per hr should be min rate). It should pick up the fuel from near the bottom of your tank in order to suck up anything on the bottom including water. Should return the fuel to the bottom of your tank in order to reduce or prevent oxidization and should not use any part of your fuel feed system.


Steve D'Antonio has an article published in Professional Boatbuilder that covers the essentials in detail.

I personally have experienced a clogged fuel line in a seaway. Believe me it wasn't fun.

[Alan Wheeler]

Yes there are high volume in line tank fill filters available. I will try and remember to get a name of it today. They are not hugely expensive, certainly not as bad as a Racor. They have a cartridge filter.

[Charlie]

I just got done with a 600 nm trip in my 1985 boat and the weather was really casuing the boat to roll. Before I left on the trip I had only had time to cut in access ports and clean one of the tanks. I didn't get too much gunk out of that tank. I had had the tank polished a year prior to taking off on this trip. Well I was down to half my fuel capacity b/c of all the gunk that came out of the uncleaned fuel tank.

When the weather stopped rolling the boat all the gunk settled back into the tank and I went thru a few filters. If you can not figure out a way to cut access holes in the tank and there are baffles in the tank I don't think you will be able to clean the tank. I would bet that there is gunk in your tank that will only come out when you get in rolly conditions where the roll of the boat scrubs the tank clean or scrub the tanks yourself. You might make it if conditions are benign. But you might run into trouble too.

[Alan Wheeler]

Donaldson and Fleetguard both make the pretank filters. The one I looked t today was a Condor, but that is the company that supplies them in NZ. I suspect it is Chinese.

[DeepFrz]

Here is an interesting article that I think speaks to the "polishing" vs "non-polishing" question. I think it speaks to the "filter while fueling answer" that Alan prefers. I do believe that filtering while fueling is a "good" thing, but I also think that it is only one part of the answer when trying to avoid fuel problems.

The Beauty of the Jury Rig - SailNet Community

Edit: Alan, do you have a link for us?

[Roy M]

I used to have a big, honking Fram fuel filter just before my fuel tank. It is the white housing that you see at the fuel docks in San Diego, prior to the pump. It was located about four feet below the deck fuel fitting. When filling my fuel tank, I would fill slowly and things would be dandy. If I tried to fill at the capacity of the pump, the fill pipe would want to overflow. Eventually I removed it and gave it to a fisherman. I regret doing so, because now I am going to build a portable unit, to drain customer's tanks into a drum, then pump the fuel back into the tank after it has been hand cleaned. Coming out and going back in, it will have been filtered completely, twice. I can take samples form the storage drum to confirm the clarity of the fuel. When I go cruising, I can make a bit of $$ cleaning fuel tanks with very little equipment, and a case or two of filter cartridges (they're pretty large, about 6" diameter by 10" high.