Multistage diesel filtration

Sailingfun

Member III
With my lazy jack project almost on track, I switch my attention to the diesel engine.
My appointment for bottom paint is close so I need to reattach the new tank (fairly easy) and reinforce the diesel filter system.
Until now, "tototo" has a single racor 500 fg with a 2-micron filter unit. I opened today the unit and the element is absolutely and totally nasty. Time to do something better.
From a past project, I have 2 other racor 500 units so I was thinking escalate 10 micro/5 micro/2 micros.
But Ohh god from the Olympus! Racor does not produce a 5 micro-unit.
So back to the square one. I can install a napa commercial unit with the spinner and water separator (if I find a cheap cap unit) or tried to find 5 micro-unit that fit the racor 500.
But I remember I have a reloc cap for filter.. maybe I'm lucky and it's the same size as the napa filter
 

Alan Gomes

Sustaining Member
If I follow correctly what you are saying, you are contemplating adding two more Racor 500s in series with your existing one. If so, I definitely wouldn't bother doing that.

I have a single Racor 500 on my Yanmar 1GM with a 10 micron filter. That's it. I removed the on-engine filter because I don't believe it is necessary, it is difficult to change, the housing on the Yanmar is prone to developing leaks, and it is one less thing to bleed during filter changes. A Racor 500 is a truly massive filter for my little 1GM, but the filters are a snap to change (even in a seaway) and are cheaper than my previous small Racor filter.

I think a 2 micron element is too fine. While it might seem as though the finer the better, it works your pump harder due to the restricted flow, and will run the risk of shortening your pump's life.

If you are seeing really nasty filter elements, my recommendation would be to put your time and effort into thoroughly cleaning your tank. Whenever I check my filter it is always clean. I will change it periodically "just because," and because the element itself can eventually degrade somewhat over time. But really, if it were just a matter of it fouling, it would be quite a long time before I ever *had to* change it.

(By the way: I have a really slick setup for bleeding the entire fuel system during filter changes that I could share with you should you be interested. I can do it with the flick of a switch. I actually enjoy filter changes now--though, as I said, I don't need to do them very often at all.)

If you wanted to, you could easily (and farily inexpensively) add a vacuum gauge to your Racor 500, which would alert you to when it is starting to clog. If you do get one, make absolutely certain it has a resettable indexing pointer. If you don't, it will only read while the engine is running and drop to zero once it is stopped--not terribly useful. You want to know if anything caused the pointer to move when you *weren't* observing the engine actually running at speed. I have such a gauge and I've confirmed that it works by pulling a vacuum on it, but for me the needle never moves on it because I have a clean tank. But I'm glad to have it to alert me should problems arise.
 

Alan Gomes

Sustaining Member
Oh...I just re-read your post a bit more carefully, and it appears that you are installing a *new tank.* So it sounds as though you will have the dirty tank thing taken care of then? If so, then it seems all the more reason not to worry about clogging filters going forward. If you are scrupulous about adding biocide to your fuel, you'll keep the bugs at bay.
 

Sailingfun

Member III
I have a new, shiny aluminum tank.
A multistage filter is a standard for all diesel engines.
2 micros are the best that can happen to a diesel engine. How big are the holes at the sprayer at the end of the injector?
10 micro is too big, way too big for diesel and it's the fastest way to have a problem down the road.
On a small sailboat, cleaning the diesel tank is almost impossible.
I think it's a good idea to take a look at this old article:
I still have nightmares regarding clean diesel tanks (especially big ones). I pass.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Many sailboats use a 2 micron filter on the engine (secondary filter) and a 10 or even 30 micron filter on the primary (Racor).

Your citation does not support the statement that 10 micron filters are a dire problem.
 

Alan Gomes

Sustaining Member
I found the following information from MaineSail convincing as to why using a 2 micron filter on engines like ours is not a good idea. It also contains good information direct from the manufacturers' reps on our engines (Universal/Westerbeke and Yanmar).

In the case we are considering it would be even worse, because with three filters in series ahead of the on-engine filter (4 filters total?), as proposed, each filter adds a certain amount of restriction even when clean, never mind once it starts to clog. This will shorten the life of the engine's lift pump, which is not designed to handle that kind of restriction, and will lead to premature failure. Additonally, it might wind up starving the engine for fuel at higher rpm.

The original post states, "I opened today the unit and the element is absolutely and totally nasty. Time to do something better." Personally, what I think would have been better would be to change out the filter at a more frequent interval, before the elements become absolutely and totally nasty. They are cheap and easy to change on a Racor 500, and with a vacuum gauge one would be able to see when the filter was becoming crudded up long before it became absolutely and totally nasty.

Re: removal of my on-engine filter: The on-engine filter on my Yanmar is (was) something like 15 or 20 microns (I forget which right off). Therefore, it should (and always did) turn up clean since the massively large filter upstream of it was finer than it (10 microns). (And, as I said, my 10 micron filter always comes up clean anyway because I have a clean tank.) However, the filter housing on my particular engine (1GM) is known for developing stress cracks and air intrusion, and the filters are also relatively difficult to change without making a mess. It was also an additional bleed point, which sometimes gave me problems. (Not from a crack in the housing but, I think, from a plastic washer on the bleed screw that sometimes didn't seat properly.) In my case, removing it has simplified my system with no adverse effects and eliminated certain problems I had with it, though I might have just left it alone under other circumstances or on a different engine.
 
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Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
I agree with MaineSail and with Alan, 100%. "And I am unanimous in that." :)
One note about the factory spin-on filter: During one summer cruise our equally old Racor model with the double O ring construction sprung an invisible air ("vacuum") leak and we solved the problem by by-passing it and using only the factory spin-on filter for the rest of the summer. Nice to have a 'plan b' in place, as it were. Good also to have some extra hose bits and clamps on hand, too.
 

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Pont is that the primary filter shouldn't be less than 10 microns. I doubt very much that a 2-micron secondary filter is a problem.
 

goldenstate

Sustaining Member
Blogs Author
I'm going with, "Refer to the owner's manual" on this one.
What kind of engine does Tototo have and what do the engine designers recommend?

I have a 30 micron primary Racor filter that is replaced each filter service.
I have a Yanmar factory secondary filter that can be washed out/rinsed out several cycles before replacement.
I think it's 5 microns.

The idea, as I understand it, is that the big Racor has the first look and gets out the big stuff, the smaller yanmar element gets the small stuff, after.

I haven't observed a problem with algae junk in the Bay Area.
I used approximately 20 gallons of diesel (1 full tank) in my first year of ownership.

This guy is my sensei on this topic. He seems Canadian and therefore credible.

 

Alan Gomes

Sustaining Member
I'm going with, "Refer to the owner's manual" on this one.
What kind of engine does Tototo have and what do the engine designers recommend?

I have a 30 micron primary Racor filter that is replaced each filter service.
I have a Yanmar factory secondary filter that can be washed out/rinsed out several cycles before replacement.
I think it's 5 microns.

The idea, as I understand it, is that the big Racor has the first look and gets out the big stuff, the smaller yanmar element gets the small stuff, after.

I haven't observed a problem with algae junk in the Bay Area.
I used approximately 20 gallons of diesel (1 full tank) in my first year of ownership.

This guy is my sensei on this topic. He seems Canadian and therefore credible.

Though I've seen some conflicting information on this, based on this one source it appears that your (and my former) on-engine filter (secondary) is 10-15 microns, not 5.
 

Kenneth K

Contributing Partner
Blogs Author
I agree that the engine-mounted, spin-on filters are often installed in a horrible location and are difficult to change, even more so without making a mess. They are usually just bolted on to the block with two bolts, and use two hose connection so they are easy to move. Here is where I moved mine:

OLD: 20161102_114322.jpg NEW: 20200521_193110.jpg

There is a bleed screw on top of the spin-on filter housing but I've never used it. I bleed the entire line after changing all filters with the bleed/return line at the injector pump. Last time I did a filter change, I left the filter cartridges empty when I re-installed them just to see how long it would take to refill them up and bleed the line with the bleeder-valve wide open. I think it took about 30-40 seconds.

Bleed/return line: 20170413_202231.jpg
 

racushman

O34 - Los Angeles
2 micros are the best that can happen to a diesel engine. How big are the holes at the sprayer at the end of the injector?
10 micro is too big, way too big for diesel and it's the fastest way to have a problem down the road.
On a prior boat I had a Yanmar 2QM and the Racor 500 (intalled by prior owner). I also used to assume that it would always be better to filter to 2 microns as opposed to 10 or 30. Cleaner fuel is better for the engine!! Right?

And even though I took much care with tank cleanliness/biocide/etc, I experienced multiple engine fuel starvation episodes due to a clogged filter. Always at super inconvenient times. Somewhere I learned that at most I needed to be filtering to 10 micron, and switched to that. Had no further problems.

I'd not seen the MainSail post about this also being hard to the lift pump, but I now run a 30 micron primary filter and whatever the standard Universal spin on secondary is. All works great.
 

Sailingfun

Member III
Originally tototo come with a 40-micron inline filter and a 2 micron Racor 500. I gonna insert another racor 500fg, 10 micro as a sump filter, a caterpillar 5 micron, and a 2 micron, originally named at the Volvo manual.
Also, I will add a prime inline pump.
The engine filter is another 2 micro as "the last line" before injectors.
Surprise me somebody can trust just in one step filter, I tough is simply not enough down the years.
 

Dave G.

1984 EY30+ Ludington, MI
Not sure what the end game is in having that much filtration ? It is not necessary and you will be adding multiple points of fuel delivery failure in the process. I'm curious why you think it necessary to scrub your fuel to this extent ? Have you had a lot of issues with fuel in the past ?
 

Kenneth K

Contributing Partner
Blogs Author
The Facet cylindrical lift pumps also have a small basket filter located at the bottom of the housing. So if you're running one of those, that's actually the first line of defense against large particles coming from the tank. I don't know if all lift pumps have those.
 

vanilladuck

E32-3 / San Francisco
This thread is super timely as I'm looking to refit the fuel system on my E32-3 with an M25 engine. Here's what I have currently:

PXL_20210211_014558631.jpg PXL_20210211_013727827.jpg PXL_20210211_013759022.jpg

After some yoga poses and camera shenanigans, I found some model numbers and looked them up. The on-engine filter was especially difficult to see:

Primary filter: Parker/Racor R24S, 2μm
Lift pump: Facet cylindrical electric pump, looks pretty rusty, some potential diesel spray nearby
Secondary filter on-engine: Baldwin BF940, 4μm

This seems backwards from everything I've read on these and other forums. I'm thinking of replacing them with the following:

Primary filter: Racor 500MA with a 30μm element (2010PM-OR)
Lift pump: Facet Cube Fuel Pump (FEP12SV aka 40106)
Secondary filter on-engine: Racor R20S, 2μm spin-on filter

The questions I have are:
  1. Does this all look appropriate, model numbers, filter sizes, and such?
  2. I notice some of the fuel lines are solid metal lines. Would it be good to change these out for diesel fuel rated hoses? If so, how do I handle diameter changes between the components?
I really like relocations Ken did on his E32-3. I might try to do something similar ;)
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
For some reason I am recalling that the Universal spin-on filter mounted on the side of the engine is 10 micron, and our former (factory install on nearby bulkhead) Racor R24S was a 10 or a 20. Note that the little screen hidden in the bottom cap of the Facet lift pump is kind of a bug-catcher size mesh.
(I did once use acetone to clean off the Universal paint on that spin-on, and it was indeed another common brand underneath, altho I now forget what model. Whatever model and filtration level it was, I would maintain it, since the engineers at Kubota knew what they were doing.)

From the research done by MaineSail, I would not install the 2 m filter option on the final filter - too much restriction. Super clean fuel is theoretically a good thing, but not when it violates the "law of unintended consequences".

As for hoses, we did change out all of the factory fuel system - supply and return - hoses a decade ago, to modern USCG-rated multi-layer fuel hose. EY liked copper for their supply and it was deemed totally unnecessary by our mechanic. The OEM copper tubing we pulled out was pretty beat up during the install.
Reference: our lift pump & Racor, OEM and now. https://ericsonyachts.org/ie/ubs/new-location-racor-lift-pump.682/
 
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