Primary Diesel Filter/Water Separator Recommendation

[Dockhead]

Originally Posted by cheoah

Hi Eric, I would prioritize installing an inspection/cleaning port in your tank. The filtration is necessary and important, but I would highly recommend a way to clean it all out and start fresh.

If chronic bad fuel is a problem, I would consider the two racor approach, with an installation that allows you hot swap filters. I would also think about using it to polish as well. Should be able to use valves and a fuel pump to accomplish this. I don't think you need the largest filters really. I think if you clean the tank and have two 500's with above configuration you'll be fine and save some $$.

+1

Absolutely right.

Having a good cure available is great, but approximately 1/1000 as important as proper prevention. The OP doesn't want to think about what's at the bottom of his tanks - he'd better have them cleaned out before thinking about filters. The best filters in the world will do nothing but buy you a few minutes of time, if you've got a lot of water and dirt in the tanks. You might not notice until the worst possible time - when a storm churns up all the muck, leaving you dead in the water.

[ErikFinn]

Originally Posted by Dockhead

+1

Absolutely right.

Having a good cure available is great, but approximately 1/1000 as important as proper prevention. The OP doesn't want to think about what's at the bottom of his tanks - he'd better have them cleaned out before thinking about filters. The best filters in the world will do nothing but buy you a few minutes of time, if you've got a lot of water and dirt in the tanks. You might not notice until the worst possible time - when a storm churns up all the muck, leaving you dead in the water.

Not entirely true, the main tank does not have an inspection hatch and I'm not keen to make one.
Let me put it this way, on your car would you drill a hole into your gas tank to get access inside?

[Badsanta]

The racor 500 handles can filter 50 gals a hour. Your engine uses 2-3 gals an hour.

[Dockhead]

Originally Posted by ErikFinn

Not entirely true, the main tank does not have an inspection hatch and I'm not keen to make one.
Let me put it this way, on your car would you drill a hole into your gas tank to get access inside?

Water precipitates out of diesel fuel as a natural process. Bacteria grow at the interface between the water and the diesel. You must clean out the tanks, one way or another. Filters are no substitute for this. Unless you just don't care whether your engine works when you ask it to, or not.

[donradcliffe]

I think armchair sailors worry too much. We started out with a single Racor 200 for a Perkins 4108, and it clogged up a couple of times in 6 years, so I upgraded to a Racor 500, which never clogged in 8 years. This was with fuel scooped from 50 gallon drums in Indonesia, dipped out a fishing boat fuel tank in Costa Rica, from God knows where in Eritrea, coffee-colored fuel bought off a Brazilian boat with a broken engine--you get the picture. I usually changed the primary filters every couple of years whether they needed it or not, and only changed the secondary filters about every 5 years. I never saw the need for two filters or a polishing system, and still don't.

What I did do was pass dodgy fuel through a Baja filter before it hit the tanks, and religiously added Biobor Jr to prevent the black growing stuff.

[colemj]

Originally Posted by Badsanta

The racor 500 handles can filter 50 gals a hour. Your engine uses 2-3 gals an hour.

You need to size for the fuel flow through the filter, not the fuel usage of the engine. The flow on a 50hp will be ~10 gallons/hr, so still well within the 500.

Mark

[Delfin]

Originally Posted by ErikFinn

Not entirely true, the main tank does not have an inspection hatch and I'm not keen to make one.
Let me put it this way, on your car would you drill a hole into your gas tank to get access inside?

You're sort of right. Inspection ports are needed for diesel because diesel precipitates out asphaltene, which collects in the bottom of the tank. If you use your engine a lot while under way, you've probably sloshed up the crud and filtered it out in the normal course of using the boat so maybe you don't need an inspection port. A sump drain point, however, is essential and if you don't have that, put it at the top of the list. If you don't use the engine when underway, then I can answer the question of what's in the bottom of your tank - road tar, and an inspection port would be highly desirable.

For small tanks like yours a single Racor 500 10 or 30 micron filter is needed out of the tank (primary), before it gets to the OEM filter, which is likely 2 to 5 microns. A 30 micron filter becomes a 10 micron filter after about 5 hours of usage from picking up stuff. Clean fuel direct from the refinery is filtered to 30 microns, so if you start with a 10, you are opting to make the fuel cleaner than it was delivered. If you start with a 30, you are opting to clean the fuel if it gets crudded up, but as noted, 30s become 10s pretty fast anyway.

Don't use a filter larger than a 500 because the bigger ones are designed to have more flow running through them to work properly and you don't have that.

Just as an FYI, if you have a lot of tankage (like moi), then you polish the fuel at 30 microns, transfer it to the day tank through a 10 micron filter and put 2 micron filters on the engine before it gets to the OEM filter. Belts, suspenders, and sewing your pants to your backside, I suppose, but dirty fuel is not one of my worries.

[Astrid]

On a car, in most cases, if worst comes to worst, you can always pull the fuel tank and flush it out. That is not so easy and usually impossible on a boat. The other issue is, cars routinely use up their fuel in the tanks on a regular basis and the fuel keeps relatively mixed up with whatever impurities are present and consequently removed by the filters, so one is always filling with relatively new clean fuel unless you happen to refuel from drums of diesel you bought last year when the price was down. Boats might go for months without an appreciable change in fuel levels and it is this that can cause problems.

Like Delfin, I use a day tank which gets fuel going through polishing filters before it ever reaches the engine and its filters or the stove and heating system.

[ErikFinn]

Thank you for all your posts dear CF friends, I think I should try to get inside the tanks although this is something I'm trying to subconsciously avoid..
But is does make sense to know the condition of the insides.

The aux tank has an inspection port. The main does not. It only has the hole for the fuel level sender and I think the hole must be something like 1 - 1,5 inches in diameter. I haven't opened the cap/lid yet so can't be sure.

But I want to ask if I can clean the tank through such a small hole? What method would you guys recommend? Do you reckon I could try to just empty the tank, and then pump diesel through the hole and try to "flush" it as well as possible?

This is the original tank Beneteau installed at the factory and I don't know if it has baffles, but I suppose most boat tanks do have them?

The auxiliary tank has a larger inspection port so I should be able to inspect that better.

What would you recommend for sealing back the cap/lid on to the tank?

Erik

[Efraim]

Originally Posted by sy_gilana

I would look at the Davco unit. Nice that you can change the filter element while the engine is running. Also nice to see the state of the filter at any time. Bleeding is no problem. No need for a duplex, if it clogs just change it. Also it can accept a number of filter elements, Racors, CAV,'s Wix, Purolator, Fram, Napa, Yong Ching...any filter that is x by y dimensions...
DAVCO Technology, LLC

[Dockhead]

Originally Posted by ErikFinn

Thank you for all your posts dear CF friends, I think I should try to get inside the tanks although this is something I'm trying to subconsciously avoid..
But is does make sense to know the condition of the insides.

The aux tank has an inspection port. The main does not. It only has the hole for the fuel level sender and I think the hole must be something like 1 - 1,5 inches in diameter. I haven't opened the cap/lid yet so can't be sure.

But I want to ask if I can clean the tank through such a small hole? What method would you guys recommend? Do you reckon I could try to just empty the tank, and then pump diesel through the hole and try to "flush" it as well as possible?

This is the original tank Beneteau installed at the factory and I don't know if it has baffles, but I suppose most boat tanks do have them?

The auxiliary tank has a larger inspection port so I should be able to inspect that better.

What would you recommend for sealing back the cap/lid on to the tank?

Erik

If I were you, I would call in professional fuel polishers/tank cleaners. 1.5" is pretty tough -- they use bigger hoses than that. But I don't know why you wouldn't just cut a bigger hole. I don't think it's that hard.

[delmarrey]

Originally Posted by ErikFinn

Thank you for all your posts dear CF friends, I think I should try to get inside the tanks although this is something I'm trying to subconsciously avoid..
But is does make sense to know the condition of the insides.

The aux tank has an inspection port. The main does not. It only has the hole for the fuel level sender and I think the hole must be something like 1 - 1,5 inches in diameter. I haven't opened the cap/lid yet so can't be sure.

But I want to ask if I can clean the tank through such a small hole? What method would you guys recommend? Do you reckon I could try to just empty the tank, and then pump diesel through the hole and try to "flush" it as well as possible?

This is the original tank Beneteau installed at the factory and I don't know if it has baffles, but I suppose most boat tanks do have them?

The auxiliary tank has a larger inspection port so I should be able to inspect that better.

What would you recommend for sealing back the cap/lid on to the tank?

Erik

I sometimes use my sender hole for inspection and cleaning. If you shine a light down in the tank it should have a shinny bottom. if there is sludge you'll see black, and water you see globs thru the diesel.

Also the camera's on a wand work good too.

[skipmac]

Originally Posted by ErikFinn

Thank you for all your posts dear CF friends, I think I should try to get inside the tanks although this is something I'm trying to subconsciously avoid..
But is does make sense to know the condition of the insides.

The aux tank has an inspection port. The main does not. It only has the hole for the fuel level sender and I think the hole must be something like 1 - 1,5 inches in diameter. I haven't opened the cap/lid yet so can't be sure.

But I want to ask if I can clean the tank through such a small hole? What method would you guys recommend? Do you reckon I could try to just empty the tank, and then pump diesel through the hole and try to "flush" it as well as possible?

This is the original tank Beneteau installed at the factory and I don't know if it has baffles, but I suppose most boat tanks do have them?

The auxiliary tank has a larger inspection port so I should be able to inspect that better.

What would you recommend for sealing back the cap/lid on to the tank?

Erik

Did not review the whole thread but you mention a 1989 engine so assume your boat is a 1989. I have a 1984 boat and from what I found I highly recommend a careful inspection of the inside of the tank. Take a look at these photos I took of a piece I cut out of the bottom of my tank.

http://www.cruisersforum.com/forums/...ank-99398.html

[noelex 77]

Most boat owners eventually fit a large inspection port in their tank. To be able to mechanically clean the tank is almost essential at some point.

It is shame more boatbuilders don't take this into account.

Without this provision there are steps that can be taken to lengthen, or possibly, under ideal conditions, eliminate the mechanical cleaning of the tank.

1. Professional fuel polishing. This uses a high capacity pump to stir up the tank debris. The fuel is filtered over an hour or so.

2. As above but DIY. The components pump and filter are quite simple.

3. A permanent fuel polishing pump. This tends to be much lower capacity. By itself it will not stir up the debris in the tank to any degree, but combined with the agitation of sailing the result can be quite effective. This sort of pump can be run for several hours each day.

I have 3. Installed and my fuel and tank is cleaner. I think a major mechanical clean may be necessary at some stage but the polishing is greatly extending this time and possibly eliminating the need altogether. Time and the future fuel quality will tell.

Keep you tank clean and your engine will reward you.

[Delfin]

Originally Posted by noelex 77

Most boat owners eventually fit a large inspection port in their tank. To be able to mechanically clean the tank is almost essential at some point.

It is shame more boatbuilders don't take this into account.

Without this provision there are steps that can be taken to lengthen, or possibly, under ideal conditions, eliminate the mechanical cleaning of the tank.

1. Professional fuel polishing. This uses a high capacity pump to stir up the tank debris. The fuel is filtered over an hour or so.

2. As above but DIY. The components pump and filter are quite simple.

3. A permanent fuel polishing pump. This tends to be much lower capacity. By itself it will not stir up the debris in the tank to any degree, but combined with the agitation of sailing the result can be quite effective. This sort of pump can be run for several hours each day.

I have 3. Installed and my fuel and tank is cleaner. I think a major mechanical clean may be necessary at some stage but the polishing is greatly extending this time and possibly eliminating the need altogether. Time and the future fuel quality will tell.

Keep you tank clean and your engine will reward you.

I religiously use our polishing system on each of Delfin's 5 bulk storage tanks when there is only 20 or so gallons of a few hundred left, and then when in a seaway. By circulating 3 gallons a minute through the tank, I presume I'm picking up whatever is there to pick up. The filters stay remarkably clean, so I guess it's working. As remarked above, the key to effective polishing is pumping volume.