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letsgo
10-10-2003, 05:28
I guess I missed the posting for this question. In all the posts I have read the brand and filter number have been listed but when looking up the filters there was always multiple micron sizes, thus the two questions, I assume the correct sizing is critical for a reliable system.

What is the micron size of a pre filter and the micron size of the OEM filter when used together as a two filter system?

What is the micron size of the OEM filter and the micron size of the post filter when used together as a two filter system?

any info is appreciated.

dieselburb
10-10-2003, 06:30
check out kennedy's website. he's got a bar graph containing the infor you're looking for.

letsgo
10-10-2003, 12:27
I looked but the site doesnt answer the question.

thanks

chuntag95
10-10-2003, 12:43
letsgo,
I don't think there is a way to "calculate" the values you are looking for. Regardless of which is first, the OEM or the aftermarket, they will both filter out some number of particles in all sizes. The finer the media the more particles it will catch, but since no filter is 100% efficient, some will get through and go to the second filter. They could get stopped by the second filter, even if it is the larger size media or it could pass right through. Putting the smaller media filter second would give you a longer life for both filters vs. the smaller media first which will catch most of the particles and let the OEM only catch a few. Does that make sense? There is not a formula like you have for adding resistors or running them in parallel to see what one value is represented by both.

carco
10-10-2003, 16:14
letsgo, let me take a stab, hope I understand the quetion. On old style systems a primary filter of 20-30 microns and sec filter of say 10 micron rateing were used. On common rail high pressure systems like our Dmax I believe the figure for the OEM Racor is near 2 micron @ 60% effeciancy. If I understand correctly we need fuel a little cleaner say 2 micron or better, 90% of the time or better for the longest expected life of the injectors. Now pre OEM or post OEM I believe we are attempting to achieve 2 micron @ 90 % or better regardless of position. Hope my terminolgy is ok... HTH , bob

letsgo
10-11-2003, 07:02
It is true I

Turbine Doc
10-11-2003, 16:26
Not wanting to reopen the firestorm on filtration I'll suggest going to Racors site and reading their info and make your own decision based on what is written there or call their tech dept. basically they say 2 micron for final, maybe a 10 if fuel source is from known good source/quality, and 30 for primary. check it out at http://www.parker.com/parkersql/default.asp?type=2&id=27

Trip
10-12-2003, 04:13
The OEM is considered a 5 micron filter. CAT, Stanadyne, Racor, and others make a 2 micron filter assembly. Logic would suggest, and looking at alot of owner/operator over-the-road trucks, that you want the finer (2) micron filter as the last one in line before the pump. However, due to warranty issues, or ease of install, some folks are electing to mount the additional 2 micron filter first in line and have the 5 after. Either way, the whole objective is 2 micron filtering...no matter how you get it...you got to get it. Hope that helps.

jbplock
10-12-2003, 05:04
Letsgo,
Not all the specs we talk about are published. Depending on what type of info you are looking for you may have to contact the manufacturer directly. For instance, the Baldwin Website (http://baldwinfilter.com/) lists mechanical specs but not filter performance specs for the “2micon” BF7635 (http://catalog.baldwinfilter.com/PartSpecification.asp?URL=PartEntry.asp&partnumber=BF7635) (Mega Filter). There is also more to the spec than the “micron” rating. You also need to know the filter's efficiency at removing a particular micron sized particle. Efficiency is often specified by its “Beta” ratio for a particular particle size. Here is a paper on FILTER PERFORMANCE AND MICRON RATINGS (http://baldwinfilter.com/engineer/95_11.html). All the filters we have been discussing (in alphabetical order :D - Baldwin, (http://catalog.baldwinfilter.com/PartSpecification.asp?URL=PartEntry.asp&partnumber=BF7635) CAT, (http://www.cat.com/products/shared/parts_n_service/04_filters/fluid_filters/_filters/high_eff_fuel_filters.html) Racor, (http://www.parker.com/parkersql/default.asp?type=2&id=27) & Stanadyne (http://www.stanadyne.com/dsg/dsg_dffs.asp)) are high efficiency “2 micron” filters. Early on in the discussion we all zeroed in on the best available filters. To date it has been shown by independent fuel analysis testing by several members that the CAT, BALDWIN and RACOR filters will yield clean fuel that meets the ISO targets needed for our high pressure injection system. For a summary of these results see

Fuel Test Results - Excel (http://home.usadatanet.net/~jbplock/ISO/OC_Dmax.xls)
Fuel Test Summary - pdf (http://home.usadatanet.net/~jbplock/ISO/OC_Dmax.pdf)

Also, see ISO Contamination Codes (http://www.edm-mechatronics.com/iso_table.htm) for an explanation of the ISO cleanliness codes.

Hope this helps.. smile.gif