Fuel Fool?

[Just Plain Jeff]

A few years back I had a diesel-powered boat. The lesson that was learned very quickly was that diesel fuel in a boat has a bacterial growth which ensues from warmth, humidity and lack of use (the engine stops once the filters are clogged: Bad). So boat users use some overpriced diesel conditioner.

Can anyone make up a reasonable answer as to why we don't have to do the same with buses which aren't used much?

[Jon Wehrenberg]

I suspect your boat was in a warmer and more humid environment than most of our buses are stored in. I also suspect when you ran your boat you did not run for hours on end, depleting the fuel and refilling. It is likely your fuel in the boat was on average much older than the fuel in the typical bus.

[Just Plain Jeff]

You may well be right We had 2-250 gallon tanks and with a Ford Lehman marine engine, fuel consumption was somewhat lower, relative to storage capacity.

The other factor was that a portion of the fuel line was rubber hose. In that application, it sucked a small amount of oxygen into the engine, causing injector clogging. I replaced the rubber hosing with copper tubing and solved that side of the problem.

So then it makes sense that warmth, humidity and age of diesel fuel are the factors in bacterial growth?

Or am I missing something here?

[Jon Wehrenberg]

Warmth, humidity and age of fuel are the exact factors that promote the growth of crud in diesel (or Jet A) fuel.

[Ben]

I believe the new sponsor at Prevost-stuff has a fuel polishing system that they offer for buses. You'd have to check out their site... could have sworn I read something about it there.

I've never heard to anyone adding one to a bus.

[kmuller]

Jeff, Jon, Ben - interesting subject. Diesel contamination generally takes three forms - biological (bacteria and molds), inorganic ( grit, clay, sand or dirt known collectively as asphaltene), and water. You would be amazed where the water can come from, including the refining process, particularly associated with ultra-low-sulphur fuels.The more sophisticated our engines become (electronic, high pressure fuel injection, etc), the more critical this issue becomes.

Fuel filtration and fuel polishing are related but measurably different. The issue is not just clean fuel and the impact it has on injectors and the engine itself, but fuel tank corrosion from the sludge/water in the bottom, and a host of new issues regarding bio blended diesel as well.

We have just published a comprehensive tech article intitled "Fuel Filtration...the key to engine reliability". You will find it in the February issue of Passage Maker Magazine (in the boating section of your favorite book store), or log on to our website at Zimmermancoach.com, fill out the contact form, request a copy, and we will mail it to you.

[bill&jody]

its not just boats. the original bio problem was discovered and written up in an app note from alco diesel, the diesel electric train locomotive guys. while i was an indentured servant in the '70s, (dam, i'm gettin' old...) we used some stuff called biobor to kill the little vermin that live in the oil/water interface.

i would assume theres something equiv for our tanks - anybody use anthing special?
anybody ever try to drain the bottom sludge out?

wmm

[dalej]

I don't know much on this subject, but I use agri-diesel, its a fuel additive from fuel power. To keep diesel from doing bad things....

[Ben]

I just bought the Feb issue of Passage Maker a few days ago. It's nice to know that their contributors are starting to appear on the POG board. I'd love to live on a motoryacht whenver I decide to stop living on a Prevost.

Karl.... are you going to be at Trawler Fest in Stuart, FL? I might show up.

[Joe Cannarozzi]

A simple solution to this problem is to design the tanks by putting the fuel P-U from a sump at the very bottom of the tank instead of running a tube from the top going down that stops just short of the bottom. That way nothing is allowed to accumulate at the bottom and any water or smutz thats in the fuel is immidiatly or continualy pulled out and through an external water seperator that can be easily serviced. I know Mac uses the tube going down from the top style and those guys have to watch things closer than those of us sucking directly off the bottom like Pete and K-W.

I'm no sientist but have been told that certian fuel additives actually allow you to burn the accumulated water in the tanks by attatching a few additional molocules to the water changing its structure and making it combustable.

As far as the bacteria issue? How about get out and use it more frequently