Two micron secondaries?

[angus99]

After reading Tony Athen’s thoughts on multi-stage fuel filtration, I’m exploring replacing the Racor 500 primaries with larger Fleetguards in the 10-20 micron range with a perfect-world goal of 2-micron secondaries.

Currently, the secondaries on our Ford-Lehman 135s are 10-micron NAPA 3166 canisters; they, or equivalents, are easily available. I can’t find a comparable 2 micron filter cartridge for the Lehman engine and just wondered what others are using as secondaries.

Seems I recall Brian Smith saying getting down to 2 microns for the 135 wasn’t necessary. If I’m recalling that correctly, how would you FL owners achieve multi-stage filtration?

 

[RT Firefly]

Greetings,
Mr. 99. I'm pretty sure I have 2 micron secondaries (CAV) on our 120's but I'm not aboard so can't check. I also think I'm running 2 micron in the Racors as well. I understand there are various schools of thought regarding graduated filtration but the system has been working quite well for me for the last 10 years or so.

 

[dhays]

What do your engines call for? If the engines want 10 micron filtration, I'm not sure you gain anything by filtering to 2 microns.

 

[psneeld]

The first thing I did was get rid of those complicated OEM secondary filters and get a simple screw on system that took easy to get filters.

One screw to bleed, extra in/out ports if I need to add an emergency pump, tank, etc.....

That solved my problem... Not sure if you want to do that.

 

[Nocanvas]

Is it possible on a 480 HP Cummings that I think specs a 3 micron on the engine and a 10 Micron primary.

Just go with me on this ; If the primary is changed to a 2 micron it would be inhibiting the fuel flow enough that the engine can't reach full rpm ?

 

[O C Diver]

I have read Tony's opinion on multi stage filtration. For commercial applications and passage making, I see some merit. As you seem to be meticulous about acquisition, filtration, and fuel polishing, think you could be quite happy with 2 micron filters in your Racors as already suggested. If I were starting over in your situation, I would prefer Racor 900s or 1000s. IMO, the filter bowl is a window into your fuel and filtration. To me, it's like an engine gauge versus an idiot light. The bowl like the engine gauge shows you change (hopefully before it reaches critical mass). The filter like the idiot light offers no preemptive warning before failure.

Ted

 

[Russell Clifton]

My Racor filters are a lot easier to service than the secondary filters on the engine. So I run two micron filters in the Racors (dual set up on each engine) and not worry about the secondaries. Nothing big enough for the secondary filter to catch.

 

[Civilitas]

Is it possible on a 480 HP Cummings that I think specs a 3 micron on the engine and a 10 Micron primary.

Just go with me on this ; If the primary is changed to a 2 micron it would be inhibiting the fuel flow enough that the engine can't reach full rpm ?

No. A fuel molecule is around 2,000 picometers. 2 microns is 2 million picometers. So the notional “hole” in the filter is right at a thousand times larger than your fuel size.

This is like landing a 747 on a strip 37 miles wide.

As a filter loads with material, its efficiency improves. But not to the point of restricting flow of something that small unless in the extreme case of running it for ages and with flthy fuel. And this filter should only be seeing the downstream product of the pre-filter.

 

[smitty477]

I have read Tony's opinion on multi stage filtration. For commercial applications and passage making, I see some merit. As you seem to be meticulous about acquisition, filtration, and fuel polishing, think you could be quite happy with 2 micron filters in your Racors as already suggested. If I were starting over in your situation, I would prefer Racor 900s or 1000s. IMO, the filter bowl is a window into your fuel and filtration. To me, it's like an engine gauge versus an idiot light. The bowl like the engine gauge shows you change (hopefully before it reaches critical mass). The filter like the idiot light offers no preemptive warning before failure.

Ted

A vacuum gage on a fuel filter is a gauge vs an idiot light. It is a very cheap device that can diagnose potential problems and tell you when required maintenance is coming due.

 

[dhays]

Is it possible on a 480 HP Cummings that I think specs a 3 micron on the engine and a 10 Micron primary.

Just go with me on this ; If the primary is changed to a 2 micron it would be inhibiting the fuel flow enough that the engine can't reach full rpm ?

IIRC, the secondary filters on the Cummins is a 2 micron filter. They recommend 10 micron primaries. I agree with you that it is possible to filter too much and reduce fuel flow. However, I've yet to hear from a Cummins QSB owner that has used 2 micron primary filters that has had problems with fuel flow as a result. I still use the 10 microns.


However, the Ford Lehmans are a different engine than our Cummins.

 

[O C Diver]

Is it possible on a 480 HP Cummings that I think specs a 3 micron on the engine and a 10 Micron primary.

Just go with me on this ; If the primary is changed to a 2 micron it would be inhibiting the fuel flow enough that the engine can't reach full rpm ?

I ran both a 300 and a 450 C series Cummins on Racor 1000 filters with 2 micron elements without issue. Would encourage you to add a vacuum gauge as this indicates when there is some flow restriction (vacuum increases) well before it reaches critical mass.

Ted

 

[O C Diver]

A vacuum gage on a fuel filter is a gauge vs an idiot light. It is a very cheap device that can diagnose potential problems and tell you when required maintenance is coming due.

Yes, have vacuum gauges at the helm for both engine filtration and fuel polishing. The bowls on the Racors (which are checked each morning) have been more beneficial with regard to fuel analysis.

Ted

 

[Nocanvas]

I ran both a 300 and a 450 C series Cummins on Racor 1000 filters with 2 micron elements without issue. Would encourage you to add a vacuum gauge as this indicates when there is some flow restriction (vacuum increases) well before it reaches critical mass.

Ted

The dual Racors are installed with vacuume gauge at this time.

 

[bayview]

With my 450 Cummins never had a flow restriction problem with 2 micron but went back to 10mbecause they didn't seem to make any difference.

IMO a clear bowl filter is a must. It really helps my confidence to see the color of the fuel.

Your old Lehman's can probably digest rocks so I wouldn't worry about microns. The new common rail engines are a very different story.

 

[smitty477]

Yes, have vacuum gauges at the helm for both engine filtration and fuel polishing. The bowls on the Racors (which are checked each morning) have been more beneficial with regard to fuel analysis.

Ted

The bowls that are checked each morning - is that for water?

 

[smitty477]

With my 450 Cummins never had a flow restriction problem with 2 micron but went back to 10mbecause they didn't seem to make any difference.

IMO a clear bowl filter is a must. It really helps my confidence to see the color of the fuel.

Your old Lehman's can probably digest rocks so I wouldn't worry about microns. The new common rail engines are a very different story.

"IMO a clear bowl filter is a must. It really helps my confidence to see the color of the fuel."
Are you utilizing a color chart along with a designated back light?

 

[smitty477]

My Racor filters are a lot easier to service than the secondary filters on the engine. So I run two micron filters in the Racors (dual set up on each engine) and not worry about the secondaries. Nothing big enough for the secondary filter to catch.

Standard 2 micron Racor filters will pass particle sizes above 2 micron. Secondary's will need attention at various intervals but at a lower frequency.

 

[RT Firefly]

Greetings,
Mr. dh. Re: post #3. I have no idea what I gain by filtering to 2 microns but as I mentioned, it's been working satisfactorily for the last 10 years so I have no incentive to change. As mentioned by Mr. RC (post #7) the Racors are a LOT easier to service than the CAV filters so anything I can do to extend the change time for the CAV's is a bonus. YMMV. The last time I changed the CAV filters I did an autopsy on one and it appeared as new in spite of the fact that it had been in place for a LONG time (3 or 4 years, perhaps?)



I do have vacuum gauges on the Racors.

 

[dhays]

Clear bowls are great. However, the requirement to have a metal shield around the bowl makes getting a good look at them a bit of a pain. Not bad for those of you who have actual engine ROOMS as opposed to those of us who have an engine compartment.

 

[sunchaser]

Angus. Brian Smith's advice is worth listening to.

The good thing about Tony's (and the filter manufacturers') 30, 10 and on engine filter system is it pretty well eliminates the perceived need for the oft mentioned low tech fuel "polishing" systems.

Sure, almost any non text book setup and micron size works if you have clean pump fuel and tanks and burn a small amount of fuel per year. But for those burning many thousands of gallons per year, staged filtration with spin ons is pretty nice.

Along with anchors, fuel filtration seems a popular topic. Maybe because there are few wrong ways for those that seldom anchor in challenging conditions or burn a few hundred gallons per month of fuel.

 

[Lepke]

I've been running diesels for a long time and super filter my fuel and oil. Wear is caused by debris, big and small, in the fluid. Having clean oil and fuel greatly increases the life of engines, fuel pumps and injectors. I rarely have had to change an injector or pump before I rebuild the engine. I run 2 micron fuel filters in Racor 900s and before I centrifuged my oil I ran bypass filters that removed oil debris below 5 microns.
In commercial use I got 1000s of hours more before rebuild than others running the same engines.

 

[caltexflanc]

I subscribe to a very unique approach to this never ending issue:

Use what the engine manufacturer tells you to use.

 

[O C Diver]

The bowls that are checked each morning - is that for water?

While I do look for water or sediment in the bottom of the bowl, contaminants often hang on the slots that make the fuel swirl in the bowl. Also particles spun from the fuel, collect on the bowl. Simply, if the bowl isn't clear, you need to figure out what level of contaminants you're dealing with.

Ted

 

[jleonard]

First filter is a Racor 900 at 30 micron. Second dual Racor 500 is at 10 micron. The original setup of dual elements ofr the FL 120 is at 7 micron (I believe).
That's my multi stage setup.

 

[sunchaser]

Great setup Jay. Something for Angus to consider.

 

[angus99]

I’ll second Sunchaser on that, Jay.

If your on-engine filters are 7 micron, I’d love to have the model number. I haven’t found any less than 10.

 

[smitty477]

While I do look for water or sediment in the bottom of the bowl, contaminants often hang on the slots that make the fuel swirl in the bowl. Also particles spun from the fuel, collect on the bowl. Simply, if the bowl isn't clear, you need to figure out what level of contaminants you're dealing with.

Ted

I find that the vacuum gage readings along with engine hours since the last filter change will supply a reliable and consistent metric of filter life left as well as fuel supply contaminants.

 

[TowLou]

In the end the cleaner your fuel is the more life you will get from you engine. I'm all for a 2 micron final. Especially the newer engines and with this ulsd fuel you loose a little bit of lubrication in your system.

 

[smitty477]

I subscribe to a very unique approach to this never ending issue:

Use what the engine manufacturer tells you to use.

Absolutely - an approach that subscribes to the engine and filter manufacturers
listed requirements is what we have always done.

 

[bayview]

No Smitty nothing so sophisticated as a black light and color chart.

A simple small LED flash light shined through the fuel gives a good first level clue of any beginning problems.

It only takes seconds when doing prestart ER checks.