Filter Element, 5 Micron to small?

[Pete]

I have a Racor 500 as my Primary filter. How small of a filter element can I get away with (or should)? Example, "Will a 5 micron just starve the engine or be fine for fuel flow but gunk-up (technical term ) up to quickly?"

There are several threads about multi-configurations of filters in series to address cleaning fuel. But I did not see any clear, this size works well, better, best, etc.


Thank you,

P.S. My engine is a Univ. M25

[tartansailor]

My old power boat had a Racor fuel filter whose 5u element was replaced yearly as a PM regimen. Since my engine burned 5.7 gal /hr and I ran it at least 100 hours / year, I see no reason for you to be unduly concerned, as long as you monitor the clear plastic bowl below. My only problem was water and that was bled periodically.
Dick

[Kurt]

As an FYI...Racor makes a vacum guage that can installed on the outlet side of your 5 micron filter. When the engine has to start sucking harder to get fuel...the guage will tell you it's time to change the filter

[Kurt]

As an FYI...Racor makes a vacum guage that can installed on the outlet side of your 5 micron filter. When the engine has to start sucking harder to get fuel...the guage will tell you it's time to change the filter

[Tom in Cambria]

When I bought the Racor filter for my M25 Universal diesel, the shop that sold it to me recommended I use one micron filter elements. That's what I've done with no problems, so a 5 micron shouldn't be any problem. These little engines that don't use much fuel don't have a problem with fine filters. Big engines that suck a lot of fuel through them might. I think the filter elements are the brown ones, but I'd have to look again to make sure.

[Chuck]

I only found 2, 10, and 30 Micron filters, on their web site. Am I missing something?

[Tom in Cambria]

It's been a couple years since I got my Racor and I bought a half dozen filter elements at the time. I may have the sizes mixed up, but I'm pretty sure I'm using the brown one which is the finest they make. It may be the 2 micron. The black Fram filter that it replaced may have been the 1 micron one, but in any case 5 micron shouldn't present a problem in terms of impeding the flow. Sorry for the confusion. I'll check the next time I'm at the boat.

[Shanna Paxton]

I also use the brown racor filter which I believe is 2 microns. After my fuel filter issues previously reported on at length on the Belhaven trip, I would prefer that filter to get gunked up first rather than the two smaller secondary filters. I change my primary filter now every 20 hours or so, and certainly after a long trip or really rough seas.

[bottomscraper]

For what it's worth I run the brown 2 Micron Racor secondary filters on Mahalo (Perkins 4-108 and change them each year (about 80 hrs)) The primary (final) filters on the engine are not marked so I'm not sure what the micron rating is. We have used Perkins part number 26561117 and lately the Gradall 9103-4005 which has a much better gasket setup.

• Brown = 2 Micron Model 2010SM-OR
  Blue = 10 Micron 2010TM-OR
  Red = 30 Micron 2010PM-OR

(Note this posting has been updated with more accurate information.)

[Oswego John]

Hi Rich,

Can you or anyone else tell me the reason that some people put fuel filters in series? My thinking is that if any one of the filters in line clog, the entire fuel system shuts down.

For several reasons, I have been a proponent of a valved off parallel path for the fuel.

Any comments pro or con?

O J

[Kurt]

OJ,
The commonly used Racor filter also acts as a water separtor with sight glass. The racor has a drain in the bottom allowing water to be removed from the system if necessary. The OEM filters found on most marine diesels don't provide said function. The racor also does a better job of filtering (down to 2 microns) and is physially larger thus allowing more filtering to occur before getting plugged up.
Kurt

[Oswego John]

Hi Kurt,

Thanks for the reply in regard to filters. Also, many thanks for that info about the Beta 10 being the same block as the B2 482. I had a suspicion that they were close. And then Dick Barthel tells us that the Yanmar 1GM has the same block as the 1 GM 10. Now I'm wondering if the 1 GM 10 gets it's 1-1/2 extra HP from a higher RPM.

Back to filters. I agree that the Racor is a good filter to use. Better than OEM like Fram, etc. The additional water trap is useful, too.

But what I am trying to find out is why some people install more than one filter in series with each other. I read of this from time to time. I'm not sure but I think that Shanna Paxton Merrell mentioned a few posts earlier that she uses a 2 micron cartridge in conjunction with 2 smaller filters.

Is there a reason for this? I can understand a water trap in line with a filter. I can't figure out why a filter filters a second or third filter. I think it would work better with some parallel filtering. There's probably a very good reason why they do it. I just don't know the reason and am trying to know what it is.

Anyone?

O J

[Kurt]

Every setup I've seen uses just two filters. A Racor or other bulkhead mounted filter in conjunction with the engine mounted filter supplied by the engine's manufacturer. There are fuel polishing systems that use more filters and pumps...but that's a different discussion.

[bottomscraper]

Mahalo has 2 filters in series. The Racor is first in line and then the Perkins supplied secondary. The secondary is a pain to replace and requires bleeding the engine when done. The Racor was added 2 years ago to replace the older Fram unit. It was relocated to make access easier and has a clear site bowl. I can change this without bleeding the engine.

The Perkins secondary is located near the rear of the engine and has a very poorly designed gasket setup. I don't want to rag on an entire culture but having worked for a British engineering company I suspect they got it wrong but were too damn stubborn to change it. Anyway there is a better solution. Foley Engine sell "Gradall" filters that fit and have a much wider better sealing gasket. I strongly recommend that anyone with a Perkins give them a call and get some of the Gradall filters : http://www.foleyengines.com/home.html.

[Oswego John]

'
Kurt and Rich,

Thanks, I see the reason now. The added on Racor is now the primary filter. Some may think that my question should be filed under "Dumb Questions". I just didn't understand *WHY* a filter filtered another filter. Sometimes you can't see the forest because the trees are in the way.

Talk about someone getting egg on one's face. A few years back, Mike Ritenour was making plans to sail down the St. Laurence River and tour the Maritimes on La Vida. He made a post mentioning that he was thinking of installing a second fuel filter in series and invited any thoughts on the subject. Well, I piped up and told him, in my own inimitable way, that I thought that it would be better if he put it in parallel.

Well, as a result, Mike and others were kind enough to excuse my ignorance by not making a big megillah of my reply. In truth, up until this morning, I had always believed that parallel was the way to go.

Thanks again, guys

O J