I've used the Ryco Z418 oil filter for quite some time, both on the K100 and now on my K12LT. I finally got around to contacting Ryco with a technical inquiry regarding the oil filter bypas valve. Yesterday I received an answer, details are as follows - BMW OEM oil filter (which is by Knecht or Mahle) is stated in the workshop manual as opening at 1.5 Bar (21 psi). The Ryco Z418 bypass valve opens at 1 Bar (15 psi). What does this mean for us ? Well, 2 things really - when the oil is cold the bypass valve opens to allow the full flow from the oil pump to pass through at the required flow and pressure. Then, as the oil warms up and the pressure drop across the filter paper reduces, the bypass valve closes and we have "full flow" filtering through the paper. The second issue is related to filter contamination, when the BMW filter gets loaded up sufficiently, it will take a higher pressure drop to cause the bypass valve to open than with the Ryco filter. This means that not all the oil is filtered all of the time. Moreso with the Ryco filter (in theory). So it comes down to how dirty the oil gets, which then contaminates the filter paper, so causing the bypass valve to open. Just some tech info for those interested parties to ponder. Cheers, Dennis.

Good info, Dennis. I used to sell filters, motorbike specific, and you'd be amazed (perhaps not) how flimsy in materials and lacking in filter media some so-called brand-name filters really are.

The oil filters I know and use nowadays: HiFlo HF163, OEM BMW-specific and Fram PH6063 (which is an OEM factory knock-off), the Motobins black filter, and the US-made Perf-Form microfibre...the very best there is! Opinions and usage will vary.

Either way, Ryco or OEM, with their respective pressure openings, the engine's plain bearings get vital oil flow even with a 'clogged' filter. Better that than oil starved.

good info ....thanks dennis

Never really considered that filters varied so much............I'm currently using the Motobins black filter, so it was pleasing to see it on your 'approved' list, GITH.

Good info, Dennis.

Paul.

sidecar paul wrote:Never really considered that filters varied so much............I'm currently using the Motobins black filter, so it was pleasing to see it on your 'approved' list, GITH.
Good info, Dennis.
Paul.

I'm not the final authority (question authority!) on the subject and a lot of riders use other brands with great success. That minimal list is just what I like after having taken them apart to inspect their guts, and comparing them to other known brands that I wouldn't use. We pay our good money, have faith and rely on what's hidden from view and what most will never gaze upon far too much in too many things in life.