10 vs 21 micron filter??

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CaptBob
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10 vs 21 micron filter??

Post by CaptBob » Mon Dec 22, 2014 12:08 pm

Hello all,
Would like to get your opinion on something here.
With today's ethanol in our gas, what type of fuel and water separator are you running in your boats?
I have used both a 10 micron and 21 micron filter, and really have not noticed a difference in fuel delivery ratings. (I was told that a 10 would restrict more than a 21)

What kind of filter do you guys use?
2000 Glen-L Double Eagle "Fan-Sea"

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Bill Edmundson
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Re: 10 vs 21 micron filter??

Post by Bill Edmundson » Mon Dec 22, 2014 1:06 pm

CaptBob

Mine is 10 micron as recommended by Yamaha.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
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CaptBob
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Re: 10 vs 21 micron filter??

Post by CaptBob » Mon Dec 22, 2014 1:11 pm

Thank you, Bill!
You are always fast to respond.
My Double Eagle is running a 351 Ford V8.
Should I still use a 10 Micron?
2000 Glen-L Double Eagle "Fan-Sea"

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Bill Edmundson
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Re: 10 vs 21 micron filter??

Post by Bill Edmundson » Mon Dec 22, 2014 1:39 pm

Capt.

Paul Cane, Mr. Hot Rod, may be the best to answer you. Send him a PM if he doesn't come in soon.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

gdcarpenter
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Re: 10 vs 21 micron filter??

Post by gdcarpenter » Mon Dec 22, 2014 3:53 pm

In terms of full disclosure I run a little ZIP with a 35 HP outboard. I run a large canister type fuel filter/water separator - 10 micron. Since my fuel pump is engine mounted my filter is on the non pressurized supply side and with the little fuel my tiny boat sips it works fine.

I would think on an 'inboard' the filter would be in the pressurized part of the fuel delivery system, ergo the filter size should not matter much. I would 'err' on the finer filter rather than the coarser. The 10 micron seems to be a 'standard' of sorts for many marine engines.
This is my first, last and only boat build.

http://www.gdzipbuild.blogspot.com

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jenko
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Re: 10 vs 21 micron filter??

Post by jenko » Tue Dec 23, 2014 3:12 am

extract from ryco filter faq
What is micron rating?

A measure of the pore size in the filter media. Expressed as either ‘Nominal’ or ‘Absolute’. Nominal Rating relates to the percentage of particles at a given size that a filter can capture ie. 10 microns at 90% means it will remove 90% of particles 10 microns in size. Absolute refers to the removal of all particles at a given micron size and larger ie. 20 micron absolute means 100% of particles 20 microns or greater will be captured.

The lower the micron rating, the greater the efficiency and hence the amount of dirt that is captured.

Common oil filter micron rating is approximately 30. (Human hair is approximately 70 microns)

When comparing different filter brands micron rating, you need to make sure that the same test procedures have been followed.
From the Holley website:


10 Micron filters are recommended for use as a post filter in EFI systems

40 Micron filters are recommended for use as a post filter in carbureted systems

100 Micron filters are recommended for use as a pre filter in carbureted and EFI systems

Joris
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Re: 10 vs 21 micron filter??

Post by Joris » Tue Dec 23, 2014 11:54 pm

jenko wrote:extract from ryco filter faq
What is micron rating?
A measure of the pore size in the filter media. Expressed as either ‘Nominal’ or ‘Absolute’. Nominal Rating relates to the percentage of particles at a given size that a filter can capture ie. 10 microns at 90% means it will remove 90% of particles 10 microns in size. Absolute refers to the removal of all particles at a given micron size and larger ie. 20 micron absolute means 100% of particles 20 microns or greater will be captured.
The lower the micron rating, the greater the efficiency and hence the amount of dirt that is captured.
From the Holley website:
10 Micron filters are recommended for use as a post filter in EFI systems
40 Micron filters are recommended for use as a post filter in carbureted systems
100 Micron filters are recommended for use as a pre filter in carbureted and EFI systems
I wasnt going to say anything as these things can quickly evolve into something like the famous oil-thread but these are very incomplete answers. (I won't say misleading but it's close...)
There's a lot of money in filters, especially fuel filters, as every home-mecanic wants some flashy looking thing under the hood to show off "how well he build it".
That huge market and the possibility as a seller to increase your profit margin with 300-500% just by leaving out a few numbers makes it worth the time to look extra close to what you're buying. A filter that is marked "10 micron" but with no clear indication whether this is absolute or if nominal, which percentage or efficiency, can probably do 1/10th to 1/5th of what you think it can. Filters you find on ebay for example are known for selling "their colour" not their performance. Efficieny rating can be as low as 5%. For some application this is perfectly acceptable but for us it can turn into a nightmare real fast. Same goes for aftermarket stuff, even OEM-filters can sometimes be barely what's needed. (iow. to get the engine through warranty-period)
If you want a good fuel filtering system (and you do, even if you don't know it) the safest thing to do is to buy one from a reputable brand, preferably at a brand-dealer. You may pay a bit more but often you won't and these filters have both the SAE Beta-rating and SAE Life/Efficiency rating making them superior to the aftermarket filters or rebrand filters.
If you want so search on your own or check a sellers' story on his product, best to google the explanation on SAE-test ratings and what happens in an engine with the stuff your filters didn't catch.
Merry X-mas to all!
Joris

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Milhouse
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Re: 10 vs 21 micron filter??

Post by Milhouse » Sun Aug 19, 2018 6:49 pm

Any recommendations on where to pick up good marine rated fuel filters? I am having trouble finding a marine rated 100micron filter for use between the tanks and the pump.

I have found the 10micron filter that I will probably use for after the pump RACOR-320RRAC02

I picked up (and have since returned) an Aeromotive 12307 Fuel Filter that said it was for Marine use. I asked them if it met the USCG law and it did not; they said: Aeromotive fuel filters have not been submitted for testing to be certified to the USCG certification to the standards you have noted. If your application requires the filters be certified to this standard do not use them.

183.534 Fuel filters and strainers.
If tested under Sec. 183.590, each fuel filter and strainer, as installed in the boat, must not leak more than five ounces of fuel in 2-1/2 minutes inclusive of leaks from the fuel pump and fuel line

183.536 Seals and gaskets in fuel filters and strainers.
(b) Each gasket and each sealed joint in a fuel filter and strainer must not leak when subjected for 24 hours to a gasoline that has at least 50 percent aromatic content at the test pressure marked on the fuel tank label.
Jim
16' Ski Boat Restoration
17' Overnighter Sloop

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