Fuel filters question

[JESSEDIVER49]

The '84 GB 42 I bought a few years ago came equipped with NAPA GOLD 2 micron filters in the Primary Racors and NAPA Gold 2 micron secondary filters. I've been advised by American Diesel to run 30 micron in Primaries (Racor) and 5-10 micron in secondaries (anything but NAPA). I see the Racor R20P 30 micron for the Primary but am having difficulty finding a good secondary filter mfr choice 5-10 micron, for the Ford Lehman 120HP. Suggestions?

btw- for past 4 years I've been running the 2 micron NAPAs in primary and secondary without any hiccups.

 

[sunchaser]

The '84 GB 42 I bought a few years ago came equipped with NAPA GOLD 2 micron filters in the Primary Racors and NAPA Gold 2 micron secondary filters. I've been advised by American Diesel to run 30 micron in Primaries (Racor) and 5-10 micron in secondaries (anything but NAPA). I see the Racor R20P 30 micron for the Primary but am having difficulty finding a good secondary filter mfr choice 5-10 micron, for the Ford Lehman 120HP. Suggestions?

btw- for past 4 years I've been running the 2 micron NAPAs in primary and secondary without any hiccups.

Nothing the matter with a 30u primary if your secondary is the on engine. Is your secondary indeed the on engine filter? It seems on the low fuel flow Lehmans almost any sensible configuration works and each alternative.is passionately stated by users as "the way".

 

[caltexflanc]

Maybe a pic would help, but a Napa Gold Racor filter? That's a new one to me unless for some reason you have the small spin-on Racors.

NAPA fuel filters are rebranded WIX, why don't they like them? I used them with very good results for secondary on my Detroits with good results if I didn't have OEM handy (which I could get from the DD dealer here in NC for the same or less than aftermarket) BTW, 30/10 or inreality 30/7 was spec'd by Detroit at least. Most so-called filtration gurus recommend progressive filtration and as do most engine manufacturers for their older designs.

 

[JESSEDIVER49]

Oops I made a mistake on the primaries - I meant to write Racor 2040SM 2 micron or NAPA 3799. The secondaries are screw-ons. I've been using NAPA Gold 3358s but am now being told the primary source Wix has been having quality control issues and I should switch to a different supplier.

 

[caltexflanc]

Don't know the reliability of your source, that's a new one, but if in doubt go with Baldwin.

 

[psneeld]

well, while American Diesel's advice is usually gold. yet not always, there are many happy Ford Lehman operators that run 2 micron in both primary and secondary. Myself included and have run 3000 hpurs on the 2 microns on this rebuilt 120.

If you have very dirty fuel, sure, run 10 or 30 in your primaries, just a few less filter changes till you get cleaner fuel.

 

[Bigsfish]

J49

If you have run 2 micron filters without a problem why change? I have run 2 micron filters as primary and secondary for the past 25 years no matter what the manufacturer recommendeds No one has been able to explain to me why this isn’t best for the engine, I admit I may have to change filters more often as they get dirty faster if I get bad Fuel. That’s the trade off as the racors are easier to change than the engine mounted filter.

 

[Comodave]

I run 10 micron in the primaries and the stock secondaries that are supposed to be around 6 to 8 microns in our Lehman SP225s. I asked Bob Smith during his last seminar and he said it was fine. I never could find an actual spec on the secondaties.

 

[koliver]

I have always understood filtration needs to be dictated by the size of the smallest aperture through which the fuel has to pass. As I understand advances in diesel technology, as driven by EPA rules for better emissions, that smallest aperture is directly related to the pressure after the high pressure pump.

That said, old Lehmans have relatively low fuel pressure, so relatively large smallest openings, so get away with filtration of 30µ at the primaries and 10µ at the secondaries.

Most old engines, say technology developed before the EPA started pushing for better emissions, is mainly in the same boat no matter the brand name. My original Volvo TMD40s were certainly happy with 30/10µ filtration, my newer TAMD41s may not be so happy with that level of filtration, but I may be crediting the lack of smoke on startup to technological advances unnecessarily. I do know that newer, common rail, high fuel pressure diesels are absolutely NOT happy with a 30/10 filtration regime.

So, my conclusion is to run finer filtration now than I used to run, but not to obsess over it, as I don't have engines that require the level of filtration that the new "tier III" engines require.

I also don't believe you can hurt your engines by filtering to 2µ. Whether your primaries are catching all of the grit, right down to 2µ, or allowing the smaller chunks through to be caught at the secondaries, is a personal preference.

I think my filtration is at 10/2µ, though I need to change so infrequently, due to the high level of filtration that happens before I get the fuel, that I don't actually recall.

 

[Knot Salted]

You can continue to run 2 microns as secondary only. Am Diesel is correct about using 20-30s as primary.

 

[smitty477]

You can continue to run 2 microns as secondary only. Am Diesel is correct about using 20-30s as primary.

Yes - the best approach.
Run 2 microns or whatever the engine calls for a final filter and run a 30 or 20 as a pre filter. If you really want to extend filter life 10X over and have much easier filter changes ad a bulk filters your first filter. More to read here....

https://www.sbmar.com/articles/marine-fuel-filtration-the-seaboard-way/

 

[psneeld]

You can continue to run 2 microns as secondary only. Am Diesel is correct about using 20-30s as primary.

sorry, but like so many things in life...this topics advice is not correct or incorrect..but has many possibilities.

Some low tech engines dont care, only you have to deal with the process of filter clogging and changing.

Other higher tech engines may care in terms of restriction and pump issues...those are best to follow manufacturer guidance, not some generic one size fits all internet advice.

There are reliable sources that say the OPs question on Lehmans can be answered with several options and they all work just fine based on decades worth of service.

I seem to get good fuel. One 2 year stretch I got over 5000 miles and 1000 hours on a set of 2 micron Racors as primaries, so that was about 2000 gallons of fuel.

Sorry but I dont buy the one size fits all arguement.

I just started carrying a few 10 micron filters in case I do get some bad fuel.

now if I travelled to places with susoect fuel often and no way to replenish filters easily, I would rethink my whole filtration system and filter sizes, not just micron ratings.

 

[smitty477]

You can continue to run 2 microns as secondary only. Am Diesel is correct about using 20-30s as primary.

sorry, but like so many things in life...this topics advice is not correct or incorrect..but with many possibilities.

Some low tech engines dont care, only you have to deal with the process of filter clogging and changing.

Other higher tech engines may care in terms of restriction and pump issues...those are best to follow manufacturer guidance, not some generic one size fits all internet advice.

There are reliable sources that say the OPs question on Lehmans can be answered with several options and they all work just fine based on decades worth of service.

I am not aware of any engine manuals that specify or recommend serial filter sizes that are the same as final filtration - this includes Racor's recommendations.
Which engine manuals (low tech) recommend this practice for their powerplants?

 

[tadhana]

If you do not already read Bill Parlatore's "Following Seas " newsletter, i would recommend it. He recently published an article on filtration.

https://www.followingseas.media/blog/2018/1/18/fuel-filtration-from-within-the-industry

 

[psneeld]

I am not aware of any engine manuals that specify or recommend serial filter sizes that are the same as final filtration - this includes Racor's recommendations.
Which engine manuals (low tech) recommend this practice for their powerplants?

I dont think I said that....

I said that there are people I know and trust and others that have no reason to lie that have used 2 microns in both primaries and secondaries with no ill effects for decades. I have done it for 15000 miles and 3000 engine hours so far.

So while graduated filtration might have benefits in many cases, not always necessary .

 

[Bigsfish]

Scott

I have been using 2 micron filters both primary and secondary with no ill effects that know of, now if I get bad Fuel (hasn’t happened with frequency)I will need to change a lot of primaries and I’m willing to accept that extra cost and I tend to carry a dozen or so primaries. Having had multiple discussions with Cat and Cummins engineers I have not been convinced to change this policy and until someone comes up with a better reason I’ll continue with this practice.

 

[caltexflanc]

See my signature line.

 

[psneeld]

too bad its not always true....

there are more ways to skin a cat as life proves every day.

just like everything isnt always built to the same standards... but they are safe and meet the need...cars, boats, planes, rockets, human minds, etc...etc...

 

[smitty477]

If you do not mind taking the time and money to change filters at 3-10X the frequency and run vacuum gages to keep you from fouling filters that might cause an unsafe situation then it is certainly not a problem. On some diesel engines watching those vac gages is more important as the fuel pumps do not like to be stressed or lack a full fuel flow.

 

[catalinajack]

well, while American Diesel's advice is usually gold. yet not always, there are many happy Ford Lehman operators that run 2 micron in both primary and secondary. Myself included and have run 3000 hpurs on the 2 microns on this rebuilt 120.

If you have very dirty fuel, sure, run 10 or 30 in your primaries, just a few less filter changes till you get cleaner fuel.

I have Lehman 120's. So many answers, so many opinions. In the end, the only thing that matters (IMHO) is the final filtration number. Using a 2 micron as the primary certainly is as good as it gets barring early plugging. My setup is 10 micron primary leading to a 9 micron first on-engine secondary to a 2 micron second secondary if that makes sense. American Diesel recommends 5 - 10 ( according to another post) for final filtration. Anything lower works, don't you think regardless of where in the succession it is? As for branding, the well-known brands are probably all as good as one another.

 

[psneeld]

If you do not mind taking the time and money to change filters at 3-10X the frequency and run vacuum gages to keep you from fouling filters that might cause an unsafe situation then it is certainly not a problem. On some diesel engines watching those vac gages is more important as the fuel pumps do not like to be stressed or lack a full fuel flow.

Like many TF discussions, you fail to step back and see what you are not familiar with.

If you run a Lehman as on tbe average trawler here, you are using between 2 and 3 gallons per hour per engine.

If you cruise and keep your fuel clean, like me and many others, you probably can run a Racor 500 for years with no vacuum issues. I change more for the aquabloc feature than worrying about plugging. So once a year is my schedule, but it is a preventative, not necessary change.

I might die of old age or sell the boat long before I use up my spare 2 micron filters at this rate.

You are entitled to think whatever, but reading hundreds of posts by individuals through the years that just carry 2 micron filtets to keep it simple and cruise without issue tells me that theory is fone, reality is just as good.

As I said though, different countries fuel and different engines would probably change my mind.

 

[Bigsfish]

Thanks Smitty

Each engine has a twin Racor set up of two 2 micron filters and one primary 2 micron filter on each Cummins. Please don’t tell me the QSM11 are one of the Diesel fuel pumps that don’t like to be stressed?

 

[caltexflanc]

too bad its not always true....

there are more ways to skin a cat as life proves every day.

just like everything isnt always built to the same standards... but they are safe and meet the need...cars, boats, planes, rockets, human minds, etc...etc...

Sure if you get away with something, then in your mind the correct way isn't necessarily true any more, because you got away with an alternative set up. I speak as someone who has got away with a lot of halfazz stuff, on the water on off, but would never kid myself that any of it was the right thing to do, let alone rationalize it and encourage others to follow suit.

 

[Bigsfish]

George

Not sure I follow your reasoning. So by using a fuel filter which is finer and therefore filters the fuel to a Finer degree is somehow dangerous just because it doesn’t follow the manufacturers letter to the T. I wonder how many manufacturers have changed their recommendations because of consumer input? I know one that did!

 

[psneeld]

Sure if you get away with something, then in your mind the correct way isn't necessarily true any more, because you got away with an alternative set up. I speak as someone who has got away with a lot of halfazz stuff, on the water on off, but would never kid myself that any of it was the right thing to do, let alone rationalize it and encourage others to follow suit.

oh horse puckey...

there are many ways of rigging systems on a boat, even newbies know that.

you are a smart, experienced cruiser, but your last pist was not on the mark.

remember, there are other smart, experienced guys besides you here.

 

[Wxx3]

Nothing the matter with a 30u primary if your secondary is the on engine. Is your secondary indeed the on engine filter? It seems on the low fuel flow Lehmans almost any sensible configuration works and each alternative.is passionately stated by users as "the way".

Well said. I do like and talk to Brian at American Diesel, but in this case, i simply don't think it matters that much.
In addition, Marin wrote a very well articulated case for having the primary be the most restrictive.
And that's the practice i do, 10 micron Racors and I use Fram filters for the engine.
THis system has worked well and in over the three years and a few thousand hours, I have not seen any water or anything in the secondary Frams. (which I only change yearly, but far less than primaries.

Richard on Dauntless

 

[Lou_tribal]

On my old venerable engine I have a single CAV filter. I did not change it for the last 2 years. Bowl is perfect clean, no more than few drops of water at the end of the boating season and everything working fine. Do I refuel with exceptionally clean diesel fuel or what?

L

 

[Comodave]

I would rather change my Racor primary several times than change the secondary on engine filter once. The Racors are a snap to change the secondaries not so much.

 

[Alaskan Sea-Duction]

I use NAPA filters on my CAT 3208T/A for fuel and oil. My OEM filters were crossed referenced to NAPA. Have almost 1000 miles on the boat with no issues.

 

[psneeld]

Well, for the anal retentives that seem to alwys doubt strayers from the holy path....

My Lehman manual does not even recommend a micron size for primaries. For secondaries it doesnt either, they just assume you will use what comes on the engine. Which I tossed after the first year because of potential air leaks. Everyone at that point recommended a non manufacturer device that allowed spin ons.

One engine fuel diagram shows and talks about primaries, the next diagram shows a fuel plumbing system without even primaries.

As I posted before, there are lots of engines and systems that are very finicky the way they are treated...others not so much.

I believe that knowing the system, having a ton of experience with it and a huge dats base on how modifications have improved it without issues is hardly "getting away with it".

In my neck of the woods it is sometimes called field mods. Look at how many suggestions on improving manufacturer produced items come from dealers or the public and later turn into service bulletins. Like the spin on adapter I mentionex before. Sure they get tons of failures too...but the ones that have survived for decades, not so much.

I am NOT saying that running a 2 micron as a primary is better (depending on how difficult or costly or obtainable your secondary is), all I am is saying on Lehmans and other similar engines, it doesnt hurt a thing. You certainly aren't "getting away with anything" either..... too many have forged that path and reported no landmines.