Microns.. how low do you go?

[deniseO30]

I was told
well, you know, everyone is an authority on everything!

That a 10 micron primary filter for diesel is just right.

Racor has filters that go to way less. What do most of "yall" use for your under 50 hp engines? (just a random guess on hp)

Now that I'm going to have a new tank I'm wondering if I can get less smudge on transom by going to less microns then 10.

Also, can I keep the new tank sludge free by always using biocides?

[celenoglu]

The fuel will be clearer as you decrease the microns. But the number of particles less than 10 microns are more than the ones that are greater than 10 microns and smaller particles will pass and burm without any problem. HP is not important, nearly all diese engines use very similiar injectors that have nearly the same tubing for diesel passage.

Trying to keep the water out of the tank is more important than using biocides. The bactera live in the water and eat the diesel which is on top of water. Keeping the tank full when the boat is not in use will keep the water out. The water in a tank is generally due to condensation of water vapor resulting from temperature changes during day time and night. If you keep water out, the bacteria will not find medium to live.

[pdqaltair]

Originally Posted by celenoglu

The fuelwill be clearer as you decrease the microns. But the number of particles less than 10 microns are more than the ones that are greater than 10 microns and smaller particles will pass and burm without any problem. HP is not important, nearly all diese engines use very similiar injectors that have nearly the same tubing for diesel passage.

Trying to keep the water out of the tank is more important than using biocides. The bactera live in the water and eat the diesel which is on top of water. Keeping the tank full when the boat is not in use will keep the water out. The water in a tank is generally due to condensation of water vapor resulting from temperature changes during day time and night. If you keep water out, the bacteria will not find medium to live.

and read the ingriedients.
* there is a lot of re-labling, so 2 brands can be the same stuff.
* not fuel additives. Bio-cides are registered as pesticides and that will be on the label.
* you must rotate every few months, because no one product is "broad spectrum." I have done lab work on this, and each brand attacs different bugs, just like different human anti-biotics attack differing strains of bacteria.

[eolon]

You want a 2 micron filter as the secondary or tertiary. Clean fuel without particulates is what you want. The clearances in the injectors will not not put up with particulates for long.

10 microns is almost 0.0005" - and injector tolerances can be 0.0003"

Better safe than sorry - the downside is you may have to change the tertiary filter more often. Cheap insurance.

Best Regards,

e

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[celenoglu]

If you use a filter less than 10 microns as the first filter, it will clog more earlier. The fist filter will clean particles more than 10 microns and the second and third will clean smaller ones. Clogging will take place a lot later in this way.

[deniseO30]

Ok.. I've a racor 220 that uses a 24t element (10m) should I get a 120 and install that after it? EVERYone has 2m filters right? sounds like something worth doing?
ps: never had a probl with 10m filter.

[jason3317]

I typically use a 30 micron primary and engine mounted 10 micron secondary with no problem. Last year, I got a free supply of 10 micron 12S? Racor filters...which I used with no problem.

If Yanmar specifiied 10 micron as the OEM filter, then I see no reason to go smaller. The times when I am banging around sloshing up crap in the tank is the exact time I do not want to be changing unnecessarily small filters that got prematurely clogged.

I also think 3 inline filters (three!) is unnecessary.

[jason3317]

Originally Posted by deniseO30

Ok.. I've a racor 220 that uses a 24t element (10m) should I get a 120 and install that after it? EVERYone has 2m filters right? sounds like something worth doing?
ps: never had a probl with 10m filter.

If you add another Racor, it should likely match the 220 you already have. Cost difference is small, and the filters are interchangable, so you don't have to carry two sizes.

[ambianceack]

I had a 2um filter but then changed. I attended a Mack Boring Class last year (spring 08) and the instructor stated Yanmar recommends a 15 um for the primary. The reason is the secondary is 2um and anything less the engine will not get enough fuel on demand. I have a 3jbh 35 hp. I realize it is not a 50hp but you may want to check with a dealer or manufacturer to insure correct filter. I change both filters annually and maybe go through 20-30 gallons of fuel a season.

[eolon]

My Westerbeke 4-107 has over 6,000 hours and no rebuild, and for 35 years it has always had three filters, coarse medium, and fine (2 um).

So, with the data available to me, I like 2 um filtration.


"If you have a problem with a diesel, it always the fuel."

Best Regards,


e

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