Article: Diesel Fuel Management

You can view the page at http://clubsearay.com/content.php?4-Diesel-Fuel-Management

good advice tried and tru so to speak......what i do here in indonesia with the ****ty fuel we get is to use a micfil filter system(out of germany / micfil.com ) filtration to .5 micron.filter cleaning surface area equal to the size of a football field, racor for example 2 square feet of paper........fuel annalis report 98.5 clean... no water . micfil cannister good to 150psi .racor you would blow the lids off.micfil suck or pressurise , could never get a good life out of my racors cus they sucked ,20 micron already at 8in/mercury at 12in/m i get low pressure readings on bridge (thats using 3 big racors on each engine)put the micfils on the pressure side of lift pumps with a pressure guage,when the pressure gets over 10psi (i'm guessing)i will change (or when i get a low fuel flow indication on bridge)have 230 hrs on filters now no prob yet(supposadly i will get up to 500hrs plus from them) right now i still use the 3 racors as prefilters ,later will install RCI cyclonic fiter (no element) i get 50hrs out of the racors, they always leak and suck air)INERESTINGLY you use the same filters for oil bypass cleaning(cannister too)to half micron ,i have one boat dd8v-92's and one ddec16v-92's the filtration takes out all the 2 stroke carbon by products and quadruples my oil changes (to 600hrs)monitored regularly by oil anaysis

Great writeup on diesel fuel. Keeping the tanks full during the season makes good sense. Anyone have advise on the following?....What about long term storage in cold climates where the boat will be stored on land from Nov-April? Is it better to keep the tanks full or empty? Any special types or amount of aditives for winter storage of diesel?

Thanks!

Very helpful article - thanks. Just wish it was written two months ago - I.e., just before I encountered the power loss conditions noted. It was definitely related to algae in the tanks as the Racors were covered in the black sludge mentioned.

Other than when away on longer trips, I always fill at my marina - a quality location with a reasonably high sales volume. What I have been doing this year though, is basically only taking the tanks up to half on each fill up. Given that I haven't been taking long trips, I thought I'd be better off not lugging around an extra 1500 lbs in fuel.

This also coincided with playing around with other fuel conditioners available at major auto supply chain (Canadian Tire). I am now back to the CAT fuel conditioner.

After changing the primary and secondary filters, I had the remaining fuel polished. I'm still not running completely smooth and am encountering intermittent slight power loss - not quite getting up to maximum RPMs from time to time. I'm guessing that this means that there still some sludge in the tanks breaking off from time-to-time. I'll try the shock process outlined above to see if that completely resolves.

Thanks again for this valuable write-up.

Paul

rdarrington said:

Great writeup on diesel fuel. Keeping the tanks full during the season makes good sense. Anyone have advise on the following?....What about long term storage in cold climates where the boat will be stored on land from Nov-April? Is it better to keep the tanks full or empty? Any special types or amount of aditives for winter storage of diesel?

Thanks!

Click to expand...

Your fuel tanks are vented to the outside of the hull. That means that whatever air is in the space above the fuel in the tanks has the same consistency as the air outside the boat, which is usually moisture laden since boats are stored near water. During temperature changes that occur in winter, moisture in the air above the fuel condenses on the interior walls of the tank and water droplets run down and into the fuel below. Microbial growth occurs in diesel fuel when in the presence of water. The more water you allow to be introduced into the tanks, the greater the risk you have of microbial growth and fuel sludge in the spring or later. Once your conditions allow microbial growth to begin, it doesn't stop until you kill it with additives. Keeping your tanks full drastically reduces the amount of water introduced into your fuel. So, with diesel fuel, it is always best to keep your tanks full.....even in the winter.

There is a prevailing idea that boat owners in the north don't need to treat their fuel with additives or take the precautions those of us in the South do. I don't believe your location matters, just that it might take longer for sludge to develop in colder climates. It is far easier and cheaper to manage your fuel as though you were in the worst conditions, than it is to be forced to clean up sludge filled tanks and filters.

Frank,

I agree with you but just want to expand on the condensation issue. Correct me if I'm wrong, but I don't believe condensation develops to much during the winter months up north during temperature changes. The relative humidity of colder air is low (not much moisture in the air) and I don't think you get enough temperature change to create condensation. I think it would be most likely to occur during the fall when you have large temperature swings with warm sunny days and cold nights. If the warm air inside the tank does not cool down as quick as the air outside the tank, condensation will occur. The only reason I would think the air inside the tank would not cool down as fast as the air outside the tank is because of the fuel temperature not changing as quickly and keeping the air warm inside the tank. Condensation occurs when warm moist air comes in contact with a cool surface. (The drippping margerita glass or cold beer on a hot day). Additionally, I doubt it would ever happen in the spring as the cold fuel would keep the air in the tank colder then the air in the engine room. Just my 2 cents.......


With that said, I agree that the best defense against condensation is to keep the tank filled during lay-up.


Steve

Every geography is different.......even the the boat's location in a boat yard is a variable. Maybe northern conditions are less likely to cause condensation and maybe the ambient temps are cold enough to retard microbial formation and growth. I've had to clean up more than one fuel tank full of sludge and it is a royal PITA to deal with, not to mention the expense and inconvenience (try changing Racors in a 5-6 ft swell 100 miles offshore). I will always lean towards removing the variables and causes for dirty fuel and if I lived in the North, I would do exactly the same fuel treatment as I do now in Florida on the boat and Tennessee on my other equipmemt.

Look at post #4 in this thread and ask Paul what he thinks.................

My boat is certainly north - Georgian Bay - and I certaiinly encountered the problem this year. What I can't say is definitively is what happens over the winter.

I've had diesel boats now for 7 years. The current boat (in my third year) is stored at the marina in inside heated storage for the winter - with the temperature kept at 7C. I would expect that'd be a reasonably stable environment. The previous boat was stored outside (four years) and I never encountered a problem. I've always put the boats to bed for the winter with ~7/8th of a tank of fuel. For a gasser, I know you have to leave some room for fuel expansion - maybe this is less of, or a non-issue for diesel.

Anyway, I've definitely encountered the problem this year and I think I'm still dealing with it. We had a really crappy, damp start to the season this year, and then suddenly on Canada Day (July 1) the season turned hot and glorious and stayed that way through to Labour Day. Maybe these conditions contributed to the problem. I use fuel stabilizer at every fill.

Paul

I agree with Frank's theory 100% and see no point to take risks. I always store my boats with full tanks.

Other than Biocide, Power Service Diesel Klean and STANADYNE LUBRICITY FORMULA is there any other Fuel Stabilizer should I use for the winter storage?

In my gas boats I always used Sta-Bil additive, would you guys recommend using Sta-Bil 22254 Diesel Formula Fuel Stabilizer and Performance Improver? http://www.amazon.com/Sta-Bil-22254-Stabilizer-Performance-Improver/dp/B0030553CC

An update to my experience. First off, the stuff I had been using all summer as an additive (bought at Canadian Tire) was Power Diesel Service Kleen + Cetane boost. I'm not blaming it, but contrary to my first post, I guess I wasn't using a cheap substitute. I'm sure the cause of the problem was my "half-tanked" philosophy as per above. Anyway, I was still encountering problems, even after fuel polishing.

I first added the Racor Biocide at shock levels to the quarter-filled tanks, together with the Diesel 9-1-1 and then added another quarter tank of diesel. Went out on the water and shook things up pretty good. Waited a week, and then took it out for a longer, harder ride on October 30th for the last run of the season. I'm happy to report that the boat ran at full operating parameters - reached 2350 RPMs and 36.7 mph, for the first time in months. Went back to the fuel dock and topped it up to 7/8ths and tucked it away in the shed for the winter, after adding CAT Diesel conditioner.Lesson learned. Will be keeping the tanks more full next season! Process above is great advice.

Paul

Great article - consistant with my experiences keeping onroad trucks and diesel powered equipment 'happy' here in Minnesota where we have a biodiesel content mandate, cold winters, and hot summers.

Have never 'shocked' the tanks with biocide - but have been careful to buy only pre-treated marina fuels at high volume suppliers. Have been restricting 10M RACORs to where 2800rpm WOT is limited within hours, and 2200rpm cruise will be effected <30hrs run time.

This season I have been running Howes products - my preferred family of onroad fuel additives.

In >120hrs of total run time, i have gone through four pairs of RACOR 10M primaries, and one pair of CAT 2M secondary filters. My indicator for changing all has been the classic 'running slow' where I cannot maintain 2800 target RPM at WOT, usually characterized by problems maintaining engine synchronization.


Current cruise plan, based on the suggestions of this article:

1. Shock the tanks, agitate and leave the tanks topped off for one week prior to our late August vacation cruise
2. Switch from RACOR 10M to 30M primaries
3. Stock up on CAT secondary filters
4. Add 9-1-1 on first tank prior to cruise, which will give an opportunity to burn and filter out dead microbial chains
5. Continue to use cetane/lubricity additives and ongoing algae treatments at a maintenance level throughout the cruise

Thanks, Frank for a great article.

Never had a fuel problem with our 40 as I have followed the advice of using a biocide and additives as suggested above. However, I think the Diesel 911 may not be the right product. Looking at the manufacturer's site, http://www.powerservice.com/bk/
it looks like the BIOKLEEN is the better option as the 911 is for winter related issues.

Power Service now has a product called Clear-Diesel:

http://www.powerservice.com/cd/

It is being markets as a "fuel polishing formula" and is supposed to contain a biocide, a moisture dispersant, and is supposed to disperse contaminants.

Diesel 9-1-1 disperses moisture and will break up microbial growth so it can pass thru filters. I believe that wording was removed from the 9-1-1 packaging because the 2 products read as though they do the same thing. The main difference to me is that Clear Diesel is only good if you use it all the time and 9-1-1 can be used only when you need it (assuming you have been using Diesel Kleen and a biocide) and is extremely valuable to help clean up a dirty fuel system.

Also, this is a personal preference, but I prefer to use separate biocide, general fuel additives and lubricity enhancers because there are time when you need to shock the fuel tanks to eliminate a problem and because you can buy biocide and Diesel Kleen in concentrated versions which reduces the hassle when fueling the boat.....it is just easier to add 20z of something than it is to mess with 1.5 16 oz bottles or 70% of a 32 oz jug.