Page 2 of 2

Re: Oil Filter comparisons - EJ25 vs FB25 vs Ryco

PostPosted: Wed Oct 20, 2021 11:22 am
by aySKE
Would there be any obvious, measurable difference when using the taller can for the track?
Or it's really a preventative "option"?

Re: Oil Filter comparisons - EJ25 vs FB25 vs Ryco

PostPosted: Wed Oct 20, 2021 9:20 pm
by Yowie
Would there be any obvious, measurable difference when using the taller can for the track?
Or it's really a preventative "option"?


See the bypass valve comments above.

In theory, a larger filter with more filter media (all other things being equal) should be able to flow more oil through the filter media before oil pressure gets so high that the bypass valve opens and unfiltered oil goes into the engine.

Track driving involves sustained high revs, so in my view the larger filter will be better than a smaller filter (if your options are limited to filters with bypass valves that must fit in the stock location) in terms of the filter still acting as a filter under more conditions. Better still if you can remote-mount your oil filter and have a much larger selection of monster filters you can fit.

Having said that, only testing/experience would reveal if it is a meaningful difference. Eg for 100 degree C oil, if a small filter has its bypass valve crack at 4000 revs and a large filter at 4500 revs it wont make much difference if you are revving around at 5000 revs for a lot of the track.

From what I have read (Four Stroke Performance Tuning by A. Graham Bell, 4th edition, page 532) many racing oil filters have no bypass valve but must be more robust against burst pressure up to 200psi.

Re: Oil Filter comparisons - EJ25 vs FB25 vs Ryco

PostPosted: Mon Apr 03, 2023 5:02 pm
by jp928
The anti-drain back valve in filters is designed to stop a FILTER installed inverted (or horizontal) draining at switch off. Any normal filter will be full while the engine is running, so how any oil could drain from galleries into the filter eludes me.
jp 08 GTB 6MT wagon