Your Opinion? - Fuel Polishing or Multi-Stage Racor

[mliemon2]

We are starting to set up our boat for longer distance cruising and are onto the fuel side of the planning. I think I’ve read every existing post on fuel filters and polishing, but would like to get peoples input. We currently have two 300 gallon tanks and duplex Racor 1000s for each engine.

What do you think would be better:

1) Installing another set of duplex Racor 1000’s inline with the existing ones for multistage filtration before it hits the engine. The though here is if there is an issue, we could quickly switch to the backups.

2) Install a fuel polishing system from ESI or Reverso. This would be the most expensive option and much more work on the plumbing side. I’m not sure how effective it would be if we just took on fuel and the system doesn’t have time to run/polish.

3) Install a multi stage spin on filter system after the existing Racor 1000’s we have. THis is suggested by Tony Athens. The issue I see here is no sight gauges and I can’t swap between filters if there’s an issue. : https://www.sbmar.com/product/smx-double-double-multi-stage-quantum-kit/

Maybe there is a solution I’m not thinking of, but any help, advice, etc is appreciated. Thanks everyone!

 

[KnotYet]

Your 4th option is to create your own polishing system that is simple and low cost.

You will need a diesel fuel pump, some fittings and valves and a quality fuel filter.

I made my own system using a Gulf Coast filter but the choice of filters is yours.

For two tanks you will need 4 tee fittings, 2 installed prior to the existing filters
and 2 installed in the return lines together with a valve at each one going to and
from the polishing pump and filter.

 

[Steel N Time]

If you are actually cruising and not sitting at a dock your fuel will be constantly polished by using your engines.

The supply and return basically constantly draws more fuel than you need filtering it and dumping it back into the tank. We have two Racors for each motor, but only use one at a time, a series of valves allow us to simply switch filters while under way, so we are using a clean filter whenever we want.

We also have electric fuel pumps set on our system, change open a couple of valves, close others and you are polishing with fuel pump. Open the valve to the engine and you can prime you engine or fill the fuel filter off of the electric fuel pump…. Really easy set up, but a lot of valves.

We have three tanks and a serious of three way valves allow us to draw from one tank and return to another. More valves!

 

[RT Firefly]

Greetings,
Mr.SNT. "...constantly draws more fuel than you need...". Depends on the engine. I understand what you state is the case for Detroit Diesels but not so for Lehman diesels. Lehmans return very little back to the tank(s). I don't know about other makes.

 

[mliemon2]

Just incase its useful: We have QSC 8.3’s… their spec is 2 micron.

One thought is I could get the best of both worlds. Install a second set of duplex racers 1000’s, with a 3-way valve, pump and timer. With the value in one position, they could act as a polishing system when the boat is at rest, and I’d simply turn the valve when its time to fire up so they’re inline with the engine.

 

[Ken E.]

Agree with RTF. The Detroit 871's I had returned a lot of fuel. The Cummins 6bt's that i have now return very little. So it depends on the engine.

 

[Steel N Time]

Just incase its useful: We have QSC 8.3’s… their spec is 2 micron.

One thought is I could get the best of both worlds. Install a second set of duplex racers 1000’s, with a 3-way valve, pump and timer. With the value in one position, they could act as a polishing system when the boat is at rest, and I’d simply turn the valve when its time to fire up so they’re inline with the engine.

Believe the 2 micron is the on engine filter and they recommend against fine filters before that. Most recommend 30 at the Racor and then the engine filter(s). Some engines have a 10 then a 2, some just a ten or 2, so it is very dependent on where you filter.

 

[Steel N Time]

Greetings,
Mr.SNT. "...constantly draws more fuel than you need...". Depends on the engine. I understand what you state is the case for Detroit Diesels but not so for Lehman diesels. Lehmans return very little back to the tank(s). I don't know about other makes.

Very true… narrow focus on my part…

 

[HeadedToTexas]

My Cummins QSB doesn't return much, but enough that I have to pay attention to my fuel return valves if I want to move fuel from one tank to the other. How does the QSB compare to Lehman or Detroit?

 

[dannc]

Believe the 2 micron is the on engine filter and they recommend against fine filters before that. Most recommend 30 at the Racor and then the engine filter(s). Some engines have a 10 then a 2, some just a ten or 2, so it is very dependent on where you filter.

Pay attention to this post and check what your engine manual says about the fuel filters.

I read a blog years ago were the owner used filters that were too restrictive and not what the engine manual stated. Caused himself a bunch of problems including a non working engine in the middle of no where. Thankfully he had a sailing rig on the boat and could sail to a harbor but the engine required a bunch of work in an out of the way place. Who would have thunk putting on more restrictive filters would cause that much of a problem.

Later,
Dan

 

[fgarriso]

IMHO I would look at polishing tanks not just the fuel going to the motors.

If you would set up a manifold that would draw from any tank, polishes, then returns to any tank. It would allow you to clean tanks and fuel while running on a good tank. Quite often you will fill one tank with BAD fuel while running on a good tank.

 

[Fish53]

As the majority of diesel engine problems are fuel related my opinion is to have both with the addition of a day tank.

 

[BandB]

We are starting to set up our boat for longer distance cruising and are onto the fuel side of the planning. I think I’ve read every existing post on fuel filters and polishing, but would like to get peoples input. We currently have two 300 gallon tanks and duplex Racor 1000s for each engine.

What do you think would be better:

Longer distance cruising? Where? What cruising grounds? Just trying to understand the situation you're trying to address before recommending a solution.

 

[sunchaser]

As the majority of diesel engine problems are fuel related my opinion is to have both with the addition of a day tank.

Can't speak to your experience but not the case for me. This urban myth keeps on popping up.

To the OP, for filtering expertise consult with the sbarmarine website, THE Cummins 8.3 experts. That said, if your tanks have good access for opening them up, a good tank inspection and cleaning is recommended, especially if it is a boat that has had several owners with potentially poor fuel care habits.

 

[mliemon2]

West coast. From Alaska to Mexico. Not all in one trip, but setting the boat up to be able to head to those areas.

 

[Hemi]

If you already have dual racor 1000s, I would simply add a polishing circuit (with a Walbro fuel pump energized as needed that can be t’ed through your existing filtration with return through to a fuel manifold to your tanks. If you only have 2 fuel tanks I would think this can be accomplished with a single pump of sufficient capacity, hose and a fitting valves. This ‘should’ only be needed when you have suspect fuel or the tanks have not been sufficiently purged (which may not apply given your operating routine). As BandB noted above, you may need to further define your mission to get a more specific answer.

 

[Kubcat]

Remember the fuel pickup is not at the bottom of the tank and that the water and bug will be at the lowest point, or at least the bug will start there.

So if you are relying on the factory fuel pickup, you will never get it all out.

On boat was factory fitted with Separ filters which are a great design as gravity and centrifugal force is used to keep them clean longer.

The previous owner had a fuel incident and got the tanks professionally cleaned. They also installed Debug which looks like a fuel filter but uses magnets to break down the bug. No idea if they do anything.

I decided to polish my fuel recently, just to have piece of mind.

On my boat the manufacturer has drain ports mounted on top of the tanks. Basically a tube that goes all the way to the bottom of the tank, well below the fuel pick up point.

I purchased a fuel pump, a screen filter and a pair of Racors. One Racor with 30 micron, the next with 10 micron.

Fortunately for me, there was only clean diesel which was confirmed with a bright torch through the fuel sender hole.

 

[DDW]

My Cummins QSB doesn't return much, but enough that I have to pay attention to my fuel return valves if I want to move fuel from one tank to the other. How does the QSB compare to Lehman or Detroit?

The QSB returns quite a lot, 2 or 3x what it uses. Of course what it uses depends on rpm. The QSB spec says the fuel delivery to the engine is 50.0 g/hr, the return to the tank is 29.9 g/hr (that is at full output).

I know on mine I can transfer something like 15 gallons an hour from the return, at only 1300 rpm.

 

[BandB]

West coast. From Alaska to Mexico. Not all in one trip, but setting the boat up to be able to head to those areas.

Then I think you're looking at overkill in talking about serious polishing, which even your polishing idea is more filtering than polishing by the definitions many of us use. Add another set of filters if you want.

What else? Well, either go full speed and add a day tank and get an Alfa Laval Centrifuge or my suggestion, focus on checking fuel before you put it into your tanks. Buy some test kits, which are not expensive, and then when you fill, test some fuel first. In your cruising grounds, I only see a problem if you use pangas to fuel between Ensenada and Cabo and not a major risk there.

What you called "polishing" from Reverso or ECI needs to run the fuel 3 times or more to filter it. That's difficult and time consuming when you are full of fuel.

I'd give different advice if you were headed to South America or even more within Central America and definitely if you were crossing oceans, but very few who cruise where you're headed have greater systems.

 

[Steel N Time]

Pay attention to this post and check what your engine manual says about the fuel filters.

I read a blog years ago were the owner used filters that were too restrictive and not what the engine manual stated. Caused himself a bunch of problems including a non working engine in the middle of no where. Thankfully he had a sailing rig on the boat and could sail to a harbor but the engine required a bunch of work in an out of the way place. Who would have thunk putting on more restrictive filters would cause that much of a problem.

Later,
Dan

It common for people to cause themselves problems by over filtering and restricting flow. Too many guys think they should have 2 or 10 micron at the Racor and it will stop a boat from getting full RPM’s and cause fuel issues and potential damage. Yanmar specifically wants 30 micron primary.

 

[Fish53]

Can't speak to your experience but not the case for me. This urban myth keeps on popping up.

To the OP, for filtering expertise consult with the sbarmarine website, THE Cummins 8.3 experts. That said, if your tanks have good access for opening them up, a good tank inspection and cleaning is recommended, especially if it is a boat that has had several owners with potentially poor fuel care habits.

I doubt it could be called an "urban myth" as it's what I was specifically taught in the engine classes at the academy and in my experience over forty something years. I understand the necessity to not restrict fuel flow but I've yet to hear of fuel that's too clean.

 

[rslifkin]

Susceptibility to fuel problems depends somewhat on where you're cruising (how likely you are to take on sketchy fuel) as well as the design of the tanks.



The closer to the bottom you draw fuel from (ideally you'd draw from a sump), the less water and/or sludge you can accumulate in the tank to get stirred up and cause a problem later (as it'll get sucked up and filtered out sooner instead of accumulating and getting sucked up in filter-plugging quantities later on).

 

[Moonfish]

For anyone considering real long range cruising on a trawler, and are concerned about fuel filters and polishing, I always recommend talking to Andy Keenan at KTI Systems. He’s been a liveaboard sailor for decades, and got his “start” in aviation fuel systems.

https://www.keenanfilters.com/industries/marine/

 

[Fish53]

Susceptibility to fuel problems depends somewhat on where you're cruising (how likely you are to take on sketchy fuel) as well as the design of the tanks.



The closer to the bottom you draw fuel from (ideally you'd draw from a sump), the less water and/or sludge you can accumulate in the tank to get stirred up and cause a problem later (as it'll get sucked up and filtered out sooner instead of accumulating and getting sucked up in filter-plugging quantities later on).

Hence the utility of a day tank, a lot of gunk in a fuel tank is algae and water from condensation as well as what you get from the dock. It's true there's nothing better than starting with clean tanks but that's not an easy job on many boats.

 

[rgano]

Your 4th option is to create your own polishing system that is simple and low cost.

You will need a diesel fuel pump, some fittings and valves and a quality fuel filter.

I made my own system using a Gulf Coast filter but the choice of filters is yours.

For two tanks you will need 4 tee fittings, 2 installed prior to the existing filters
and 2 installed in the return lines together with a valve at each one going to and
from the polishing pump and filter.

This was my option, and I had four tanks on a GB42. The issue as I saw it was the Ford Lehmans did not cycle enough through to adequately perform the polishing function, especially after refueling. I tended to run from the slightly smaller foward tanks all day, and polish from the aft tanks into the forward tanks in preparation for the next day. Before refueling, I polished all the aft tank fuel I could into the forward tanks putting the new fuel aft unless I had run so low that I needed to put some forward too, in which case I recycled the forward tanks into themselves before use.

 

[Steel N Time]

Hence the utility of a day tank, a lot of gunk in a fuel tank is algae and water from condensation as well as what you get from the dock. It's true there's nothing better than starting with clean tanks but that's not an easy job on many boats.

Our 40 year old boat had not been used a lot in the previous 18 years when we bought it, Everybody kept telling use to get the tanks polished, have them pumped out, inspected and cleaned they said…. Easier said than done, trying to find someone was not easy. We asked around Kemah Texas and found no good direction…. We headed toward Panama and had two cases of Filters and figured we would polish as we go…. Once in Mexico even after going through several full tanks through the Caribbean people kept telling us to polish the tanks/fuel…. Once again people make the recommendation, but an actual company or person to do it could not be found…


So I made a tank/fuel polisher with a transfer pump and 1000 series filter, opened the top of the tank and made a wand, so I could move it around and get to the bottom of the tank. I cycled and moved it all around, keep cleaning and cleaning using 10 micron filters and scraping around the bottom of the tanks…. It was the best we could come up with and I felt they were clean… Fuel across Mexico is different colors, so it’s hard to get a visual based on color, since some places had purple fuel, some yellow, some greenish…


We have not had any fuel issues, before polishing or after, I did get some gunk off the bottom, so it was worthwhile.

 

[O C Diver]

To the OP:
Do you have the ability to draw from the very bottom of the tanks and do the tanks slope toward that pickup or tank drain? When I set up my polishing system, I was fortunate that both tanks had drains at the absolute lowest point. Because of the sloping back to front and outboard to inboard, all but about a pint will come out the drains. Most of the stuff you're trying to pick up with a tank polishing system is on the bottom. Before you start planning changes, it would be good to know if you can regularly suck the stuff off the bottom of the tanks.

Helped a friend recently set up a polishing system with a Racor 900 (already owned) and a piston style fuel pump. The pump moves 30 GPH and he runs it whenever he's underway. It does a nice job of turning over fuel as opposed to his single Lehman engine.

Ted

 

[kapnd]

Pay attention to this post and check what your engine manual says about the fuel filters.

I read a blog years ago were the owner used filters that were too restrictive and not what the engine manual stated. Caused himself a bunch of problems including a non working engine in the middle of no where. Thankfully he had a sailing rig on the boat and could sail to a harbor but the engine required a bunch of work in an out of the way place. Who would have thunk putting on more restrictive filters would cause that much of a problem. Later,
Dan

Many filters have an ideal designed flow rate that must be considered for optimal filtration results. If you’re only moving 4 or 5 gallons /hour, you dont need a big Racor 1000, because you won’t have enough flow to “spin “
the fuel, an important feature of those type of filters.
The reference above sounds like the guy went straight from tanks to a fine filter instead of using a series of graduated filters.
If he had started filtering through a 30, stepped down to a 15, and then a 5, he would likely have gotten much further on his dirty fuel.

 

[koliver]

I am guessing that your GB 47 is 2000 or newer, located in the US, so has never taken a load of bad fuel. In the last 2 decades, fuel has been oh so clean, filtered in order to get out the sulphur. Thus the tanks have no layer of gunk on the bottom and a polishing system will have little to nothing to do.
Have you any way to have a look into the tanks? Not likely unless there has been a problem and someone has put in a window. In that unlikely event, when your normal usage takes the level down, open the access panel and have a peek inside. My bet is that you won't find anything to be concerned about.
I say the above having recently had a peek into one of my own tanks. After 41 years, 6500 hours of engine use, so 26000 gal of fuel run through my tanks, much of it high sulphur in the first 2 decades, I found a layer of black sludge (Asphaltine?) about 1/8" thick on the bottom and up the sides 4 to 6". Nothing else. Did I expect it to be any different? Yes indeed! Where was all the water, algae, just plain dirt? Looks like the Racor 500s had effectively polished the fuel from the returning dribble. I have Volvos, so expect a low return. In fact I fill my stove day tank from one return line and it takes a couple of hours to fill that 2 gal tank, so I know the return is around 1 gph, from an engine burning around 2 gph.

If your plans will take you where the fuel is not filtered to get out the Sulphur, then by all means add every advantage you can.

 

[Lepke]

You can make your own polisher with a 30gph+ diesel electric pump and your existing Racor filter. Plumb it after the Racor and then back to the tank. It can run with or without the mains running, because pump valves are like check valves and only allow fuel to run in one direction.
If you think the tanks are corrupted, pick a top fuel conditioner and use a triple dose. Run the pump for a few hours. If the Racor filter doesn't plug, swap it out for a 2 micron. If that doesn't plug, you can run a 2 micron forever unless you buy really bad diesel. Get in the habit of using a good fuel conditioner and you won't have tank problems. I've run a 2 micron for the last 10 years w/o issues. I buy fuel at commercial fuel docks or places that have a high fuel volume, because the additives are fresh.