Bypass filter vs Centrifiuge recommendations

[m37charlie]

My MBE 902.912 (6.4L 6 cyl engine originally with EGR) has a factory centrifuge. With EGR and 228.3 oil (good CI4+ 15W40) it specifies an OCI of about 550hrs depending on fuel consumption rate (about 20000 mi).
The same engine without EGR in Euro 4/5 trim recommends 1200 hr OCI (about 45000 mi) with 228.5 oil (synthetic E4 meeting MB's higher specs). Interestingly, no centrifuge is fitted; the main reason it seems be on mine is the high soot input of EGR.
I removed the EGR and replaced it with a steel plate. I haven't dared going past 22000 mi yet, even with 228.5 oil. If the situation calls for it, I may do successive UOAs at 20, 30 and even 40K miles. It has a 29L sump and uses 1L every 2500 miles.

Charlie

 

[AzFireGuy79]

The way I understand centrifuges is that they only are effective when sized properly. I know they are excellent filters, but in an automotive application one would think the limited size would affect not only their ability to produce enough centrifugal force, but also their load carrying ability as well? Seems to me that a cartridge type might really be better for automotive setups.

Centrifuges are said to go below 1um. Is this really needed when the harmful particles in oil are not even in this range? I thought 2-10um or so was the range? I know submicronic(like soot that hasnt agglomerated) poses zero harm to the internals of a diesel.

 

[txgp17]

For a Duramax, the PPE centrifuge looks like the way to go. A centrifugal filter can catch a lot more junk than a media filter.

 

[Black6spdZ]

Originally Posted By: txgp17
For a Duramax, the PPE centrifuge looks like the way to go. A centrifugal filter can catch a lot more junk than a media filter.


The centrifuges work on a dmax but not near as efficiently as they should because of the reduced pressure on these oil systems LLY+.. need to remember that max efficiently on those centrifuges is reached at input pressures at about 90psi but our trucks are around 60 psi cold and 30 warm at idle.. roughly 40-50 cruising.. its just not spinning it very fast.

 

[Texan4Life]

Originally Posted By: Black6spdZ
Originally Posted By: txgp17
For a Duramax, the PPE centrifuge looks like the way to go. A centrifugal filter can catch a lot more junk than a media filter.


The centrifuges work on a dmax but not near as efficiently as they should because of the reduced pressure on these oil systems LLY+.. need to remember that max efficiently on those centrifuges is reached at input pressures at about 90psi but our trucks are around 60 psi cold and 30 warm at idle.. roughly 40-50 cruising.. its just not spinning it very fast.


don't they also need pretty good flow? like .5 to 1gpm for even the smallest ones?

 

[m37charlie]

I love centrifuges. My Unimog (OM906LA) came with one because it came with EGR, to combat soot in the oil from the EGR.
It no longer has EGR but I left the centrifuge on. My "official" (factory recommended) OCI is now 1200 hrs with Delvac 1 SHC synthetic, up from 5-700 hrs with EGR and 15W40 CI4+ oils. But the longest I've actually gone is 600 hrs/21500 mi so far.
If I were you and wanted to extend oil life/OCI, also engine life, first I would "do something" about the EGR system.
Incidentally, with 5W40 oil pressure at running speed is ~41 psi. Despite that "low" pressure, MB obviously thinks it is enough to spin the centrifuge that they themselves installed - the bypass of the centrifuge itself drops the pressure reading!

Charlie