Oil & Fuel Adding a Spin on Racor filter to a BX25

[HeLa]

It's directed to those who put the filter after the pump.

you guys have any input on this?

Heavy Duty Diesel Fuel Filter FAQs

Q: What is the difference between a primary and secondary diesel fuel filter?
A: The primary fuel filter must offer low restriction because it is mounted on the suction side of the fuel pump where normally a suction pressure of only 5-6 pounds per square inch is available. This filter has the job of protecting the transfer pump and lightening the load of the secondary fuel filter (if installed). Primary fuel filters typically have a nominal rating of 10 - 30 microns.

Secondary fuel filters are mounted between the transfer pump and the injectors. The secondary fuel filter is designed to offer full protection to the fuel injectors. Since these filters are mounted after the transfer pump they tend to see much higher pressures than primary filters. Secondary fuel filters typically have a nominal rating of 2 - 10 microns.


i had been considering a 2-micron filter installed before the pump, but this logic has me reconsidering. thoughts?

 

[3930dave]

you guys have any input on this?

Heavy Duty Diesel Fuel Filter FAQs

Q: What is the difference between a primary and secondary diesel fuel filter?
A: The primary fuel filter must offer low restriction because it is mounted on the suction side of the fuel pump where normally a suction pressure of only 5-6 pounds per square inch is available. This filter has the job of protecting the transfer pump and lightening the load of the secondary fuel filter (if installed). Primary fuel filters typically have a nominal rating of 10 - 30 microns.

Secondary fuel filters are mounted between the transfer pump and the injectors. The secondary fuel filter is designed to offer full protection to the fuel injectors. Since these filters are mounted after the transfer pump they tend to see much higher pressures than primary filters. Secondary fuel filters typically have a nominal rating of 2 - 10 microns.


i had been considering a 2-micron filter installed before the pump, but this logic has me reconsidering. thoughts?

The way a mechanic buddy explained it to me was "Many modern (as in diaphragm style) fuel pumps don't tolerate Input side restriction well - guys have upgraded the filter (smaller micron) only to end up tearing the diaphragm due to restricted fuel flow ".

If you go with a high-restriction (2u) filter, I'd take a serious look at reducing the Service Interval from what the factory filter is rated for. (Edit - meaning the same physical size of filter).

Rgds, D.

 

[Scooby074]

you guys have any input on this?

Heavy Duty Diesel Fuel Filter FAQs

Q: What is the difference between a primary and secondary diesel fuel filter?
A: The primary fuel filter must offer low restriction because it is mounted on the suction side of the fuel pump where normally a suction pressure of only 5-6 pounds per square inch is available. This filter has the job of protecting the transfer pump and lightening the load of the secondary fuel filter (if installed). Primary fuel filters typically have a nominal rating of 10 - 30 microns.

Secondary fuel filters are mounted between the transfer pump and the injectors. The secondary fuel filter is designed to offer full protection to the fuel injectors. Since these filters are mounted after the transfer pump they tend to see much higher pressures than primary filters. Secondary fuel filters typically have a nominal rating of 2 - 10 microns.


i had been considering a 2-micron filter installed before the pump, but this logic has me reconsidering. thoughts?

Install your 2 micron before the lift pump then leave your stock inline filter by the injection pump as a secondary layer of protection for the pump. The 2 micron filter will not be a restriction if you use a quality filter like a Racor. The 120a filter is significantly oversized for the amount of fuel that a BX needs.

In practice the secondary filter will not see any dirt as it is removed by the 2 micron and its only job will be to protect the injector pump if the lift pump fails or debris is introduced after the 2 micron filter somehow.

 

[HeLa]

Install your 2 micron before the lift pump then leave your stock inline filter by the injection pump as a secondary layer of protection for the pump.

this was my plan, a final line of defense for when/if the pump fails is a must.

The 2 micron filter will not be a restriction if you use a quality filter like a Racor. The 120a filter is significantly oversized for the amount of fuel that a BX needs.

thanks. this is what i was looking for.

my concern is not the micron rating of the filter at new but rather the restriction as the filter becomes clogged. naturally a 2-micron filter will clog faster than a 10-micron. high vacuum on the intake side of the lift pump will cause the pump to wear and if the lift pump is experiencing high fuel vacuum it's possible that its output will be hindered, which could lead to fuel starvation at the injection pump. since the fuel is the lubrication within the injection pump, this in turn could lead to injection pump damage. this last part is, by far, my primary concern.


i don't have D902 GPH rates handy, the link that i cited above explains:

Q: How can I estimate my engines total fuel flow rate?
A: If this information is not available from your engine or equipment manufacturer, use the following formulas for estimating purposes.

Diesel or kerosene fuel systems:
Gallons per Hour is Engine Horsepower (maximum) multiplied by 18% or GPH = HP X 0.18


23.0 hp x 0.18 = 4.14 GPH

the 120AS 2-micron filter is rated at 15 GPH. in this case i would *guess* (since i don't have mm-HG pressure drop numbers) that the filter to be sufficiently over-sized to avoid unacceptable restriction in the suction line and to be large enough not to clog to critical levels so long as the cartridge is changed frequently.


how long have you guys with 2-micron filters been running them, and how often are you changing the elements?

anyone running a racor or the like with sequential filtering, with a filter ahead of the racor (even the plastic kubota filter)?

i suppose the best solution would be similar to marine applications, replacing both filters with racors. a 10-micron followed by a 2-micron. space likely prohibits this, though.

 

[kuboman]

The racor 120 is rated 15gph which is somewhat more than your BX will put through. Don't forget that there is more fuel flowing through the filter than is burnt by the engine, which generally is almost double. Even at that your BX will only burn 1 gal/hr so the racor will have plenty of capacity. You will be amazed at how much a 2 micron will take out unless you are meticulous with your fuel. You better keep a spare filter on hand at all times.

 

[benabrazil]

I am about to do an install similar to the one mentioned above. For the folks that did this install, any advice/feedback from instalation or how it's going now that it's been installed for awhile (change in filter frequency, problems, etc.) This is all great stuff and my BX25 is starting to act up and instead of changing out the existing fuel filter and going through this again, I thought I would do the upgrade. Thanks for all the info on this. This was really good stuff. Only issue I will have is fabricating the bracket.

 

[dodge man]

Here is another pic of mine. I used some flat steel with pre drilled holes in it because I don't own a welder. I tried different locations but as far as I know, this is the best place. I've had mine on maybe a year and haven't changed it yet. I do have a spare though. I'm probably going to go 3 years before I swap mine out.

To add a little more about my bracket, I have one piece of the flat steel running horizontal mounted to the loader mount bolts. Then I have two pieces of it running vertical ( you can only see one in the pic but they are side by side), each bolted to the two holes in the filter then bolted to the horizontal piece that's on the loader bracket. It looked awfull when I did it but it has actually worked out really well.

 

[benabrazil]

Thanks dodge man. Did you use the 2 micron filter?

 

[Scooby074]

Its working great for me.

Filtered out so much crap and water. I just went and added some valves to the housing so I can shut it off if I have to do maintenance like changing the filter or cleaning the bowl (much easier than using the hose pinchers I have).

No freeze up or reduced performance issues this winter.

 

[benabrazil]

Thanks Scooby for the info. Would it be too much trouble to attach a picture of the filter with the shutoff valve. The pictures you provided were great but it didn't look like the shutoff valve was included. Want to minimize the errors I might encounter. If not, no worries. I can figure it out myself. But thanks again for the info.