According to everything I've read, the fuel flow thru ratings for all the
various Racor filters is identical. The only difference is how fast they'll
actually clog up. With clean tanks, clean fuel and installed vacuum guages to
monitor pressure, using 2 microns should be no problem at all. I've been doing
just that with my 20 year old Cummins 210's for the last 3 years (1500 engine
hours) with no problems.

Happy New Year,
Jim
@Home

Flowscan instruments wants users to stick to 10 microns or larger. That
implies that the micron size does influence the flow rate OR smaller micron
sizes clog sooner and, therefore, affect the flow rate. As I recall, DD
wants to see a 30 micron off-engine filter.

Ron Rogers

----- Original Message -----
From: "Jim Fisher" magothy1@mail.com

| According to everything I've read, the fuel flow thru ratings for all the
| various Racor filters is identical. The only difference is how fast
they'll
| actually clog up. With clean tanks, clean fuel and installed vacuum guages
to
| monitor pressure, using 2 microns should be no problem at all. I've been
doing
| just that with my 20 year old Cummins 210's for the last 3 years (1500
engine
| hours) with no problems.

Frank,
This is good news for me as I have a box of 2 micron filters for my Racors!
Thank you,
Ron
----- Original Message -----
From: "Frank Burrows" fburrows@mail.com

| Ron:
|
| Racor says the flow rate is the same. I have a vacuum gauge installed on
my
| Racors and the vacuum is the same for a 2 or a 30 micron filter. I would
| suggest that lots of other listees have similar setup and I would ask if
| anyone gets a different reading from a clean 2 or, 10 or 30 micron filter?
|
| I think this supports Racor's contention that the flow rate is the same. I
| have been using 2 microns on my Detroits for 15 years with no ill effects.
| I believe that I have cleaner fuel in my tanks because the fuel is
| constantly filtered and returned through 2 micron filters.

Here is what I have found at
http://www.filtercouncil.org/index.php?page=heavy-duty-diesel-fuel-filters

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.

Bob Clinkenbeard
24' custom trailer trawler
http://home.bellsouth.net/p/PWP-aboardbobbinalong

May be boring to some, but good information for the rest of us.

http://seagrant.uaf.edu/bookstore/boatkeeper/fuel-filters.pdf

Bob Clinkenbeard
24' custom trailer trawler
http://home.bellsouth.net/p/PWP-aboardbobbinalong