Primary Fuel Filter

[dsherburn]

30, 10, or 2 micron filter element in the primary Racor 500?

I've got a single Lister Petter 4cyl. 80hp in a Grand Banks 32.

 

[markpierce]

We use 2 micron filters for our JD engine.

 

[OreWa]

10 on the tanks and 2 on the engines.

 

[River Cruiser]

10 on the tanks and 2 on the engines.

+1


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[Pgitug]

10 micro on the Racors

 

[Drake]

2 micron on primary Racor with 10 micron on secondary in case of blockage.

 

[O C Diver]

I used to run 2 microns on all my Racors. My John Deere has a 10 micron on the engine before the lift pump and a 2 micron after the lift pump. My JD dealer was adamant about not using a 2 micron in the Racor before the engine. So now I'm using a 30 micron in the Racor. Can't find the PDF from Parker, but the 30 micron traps the vast majority of contaminants down to 2 microns with a lower vacuum requirement. If there is a second filter on the engine after the lift pump, it will take care of the small amount that makes it past the 30 micron.

My Cummins dealer said the same thing. So it will also be switched to a 30 micron in the Racor.

Ted

 

[markpierce]

My "pre-engine" Racors came with 2-micron filters, and I haven't seen a need to change that tactic.

 

[O C Diver]

My "pre-engine" Racors came with 2-micron filters, and I haven't seen a need to change that tactic.

Ok, but was that the boat builder or the engine manufacturer's recommendation? Next time you go by your JD marine dealer, ask the manufacturer's representative what they recommend and why.

Ted

 

[caltexflanc]

I followed the engine Mfr's specs (Detroit Diesel) and used a 30 primary, OEM secondary of 7, the injectors had 2 micron screens before them. In talking to a a couple of old time Detroit mechanics they couldn't ever recall having to clean the screens. Having a smaller micron filter as a primary makes zero sense. All you end up doing is unnecessarily clogging it too soon. See the many articles on line about the reasons for progressive filtration.

 

[twistedtree]

Deere specifies 30 micro on the primaries, and Cummins specifies 10 micron. I'm not aware of any engine manufacturer who specifies 2 micron for primaries, and in fact some condone it. Deere for example.

I figure the engine manufacturer knows the most about what's good for their engines. Not to diminish what they do, but boat builders just install engines according to the manufacturers specs. If you are lucky they meet all the specs and do it correctly, but often get it wrong. So I would NOT follow their lead. In fact, I would validate everything they have done or say against the manufacturers guidelines. Cummins, as an example, publishes a really good Applications Guide for each engine family that spells out all the requirements for fuel, cooling, exhaust, physical installation, etc.

And mechanics will report on what they have done in the past that has not resulted in call-backs. That has some value, but lacks any engineering analysis or testing.

So if you make a lineup of the people with a recommendation on your filters, you would have:

1) Your friend Bubba on the boat down the dock
2) Your mechanic
3) You boat builder
4) The engine manufacturer

Who's recommendation would you take?

 

[RT Firefly]

Greetings,
This topic has been discussed previously but not wrt. a Lister Peter 4 cyl./80HP. I concur with following the manufacturers recommendations but I have no idea what Lehman recommends.

In our case, 2 micron in the Racor and 2 micron in the CAV. MY reasoning behind this is it's a LOT easier to change out the Racor whilst underway than the PIA CAV system. Less than a 5 minute procedure.

Eyeballing the clear Racor bowls for sediment and/or water is done on a daily basis as part of the morning pre-start inspection ritual.

 

[psneeld]

30, 10, or 2 micron filter element in the primary Racor 500?

I've got a single Lister Petter 4cyl. 80hp in a Grand Banks 32.

Not knowing how your entire fuel system is set up....the only answer that makes sense to me if you step back far enough is to agree that progressive filtration is the way to go. It's not what I have currently but will be changing based on what I have been reading and observing for years about fuel systems.

If you have a 2 micron on your engine (because that's what the engine manufacturer specs), the next in line towards your fuel tanks should probably be 10 micron. If you have a 10 micron on the engine then 30's for the primary.

If you only get and keep clean fuel...it probably doesn't really matter for many of these older engines...but

Before I change cruising habits, and possibly buy fuel where I really cant trust its cleanliness, I may add 30 micron units prior to my 10s (still a 2 micron on the engine) and vacuum gauges for early warning.

No doubt there is merit to progressive filtration and the research behind too restrictive filtration along the line....but there seems to be quite a few experienced cruisers out there that have been or still run with nothing but 2 micron filters in their system with no issues.

Bubbas or not, damage to their systems or not....smooth running boats with nothing but 2 micron filters are still a reality. It may be because the 2 micron only boats aren't reporting problems....but that would seem strange in todays internet world.

 

[Bacchus]

10 on the tanks and 2 on the engines.

 

[sunchaser]

We use 2 micron filters for our JD engine.[/QUOTE

Does JD say they are 2 for the on engine filter bodies? On my non electronic engines nobody makes an on engine 2, they are 5 to 7 microns as deemed just fine by Cat and Perkins Sabre for the OEM injectors and injection pump.

 

[smitty477]

Staged filtration like the engine manufacturers state and same as Racor states on their site. Typically 30 or 10 in the initial filter and then most often 2 in the last filter whether that is supplied by the engine manufacturer of is it is aftermarket. Utilizing vacuum gages is an objective method to know when it is time to replace filters.

 

[Capt. Jon]

10 on the tanks and 2 on the engines.

+3

 

[O C Diver]

We use 2 micron filters for our JD engine.[/QUOTE

Does JD say they are 2 for the on engine filter bodies? On my non electronic engines nobody makes an on engine 2, they are 5 to 7 microns as deemed just fine by Cat and Perkins Sabre for the OEM injectors and injection pump.

Yes, it marked clearly on the outside of the filter. 10 micron before the lift pump and 2 micron after the lift pump.

Ted

 

[stone beach]

anyone with a Cummins should use the same size in the prefilter as the engine filter..."well thats a bold statement" I hear...or maybe it was a different retort with the same initials (bs) !!

why do I say this? because you are returning so much fuel back to the tank that pretty soon your prefilter will be doing nothing if it has a larger micron number than the engine filter, the engine filter size has already done the work.

if you have more than one filter before the engine then staging makes perfect sense.

the prefilter(s) are supposed to condition the fuel for use, they are often called conditioning filter(s), the engine filter is there to protect the engine from a fault in the conditioning system. following that understanding the final prefilter should be the same size as the engine filter.

 

[O C Diver]

anyone with a Cummins should use the same size in the prefilter as the engine filter..."well thats a bold statement" I hear...or maybe it was a different retort with the same initials (bs) !!

why do I say this? because you are returning so much fuel back to the tank that pretty soon your prefilter will be doing nothing if it has a larger micron number than the engine filter, the engine filter size has already done the work.

if you have more than one filter before the engine then staging makes perfect sense.

the prefilter(s) are supposed to condition the fuel for use, they are often called conditioning filter(s), the engine filter is there to protect the engine from a fault in the conditioning system. following that understanding the final prefilter should be the same size as the engine filter.

Your missing part of how filtration works. I'm not going to get the terms correct, but here is the principle. There is the filtration as you view it where the media is blocking / trapping particles down to a certain size. The second type I believe is called "caking". This is where the surface of the media has contaminants. Other contaminants stick to these. So, even though your element is rated at 30 microns, the filter pics up the majority of contaminants between 2 and 30 microns. Parker (Racor) has an excellent PDF on this explaining how it works. I just cant seem to find it on the internet.

Ted

 

[J105]

Three filters...two fleet guard before engine and one on engine...20,10,2

 

[cafesport]

If it's a primary as in the first filter in a filtration series then start with 30. If it's an on engine racor, perhaps used as a secondary, then it's going to be to the manufacturers spec and probably 10 or less.


Spell check via iPhone.

 

[sunchaser]

So, even though your element is rated at 30 microns, the filter pics up the majority of contaminants between 2 and 30 microns. Parker (Racor) has an excellent PDF on this explaining how it works. Ted

Precisely Ted. Filtering 101 at work.

Parker, Cat and others have done studies where the P80 can become less than 20% or the original rated filter size before rated capacity/flowrate is affected. Unless an over sized filter body, the filter blinds off or is severely restricted by this point - one of the advantages of very big filters for a given flow rate.