Questions about flow rates...Cold vs Hot

[Razl]

I was reviewing Grease's Oil Filter Study that compares flow rates of various media swatches at 70F. I found the overall spread surprisingly big, which leaves me questioning whether the difference in flow diminishes with higher (normal operating) temps.

Not using actual numbers, let's say Media "A" flows 2x better than Media "B" at 70F. At 190F, do you think "A" would still flow 2x better than "B", or is it possible the oil thins enough were "A" & "B" have less than a 2X difference oe even the same flow rates?

I have 2 cases of the UPF filters that I bought about a year ago based on AC Delco's data, claiming highest filtration and excellent flow. This study has me questioning whether I should get rid of them on eBay

 

[427Z06]

If memory serves, once you run the numbers, you find that at anything above 150F even the most restrictive filter will flow well enough to prevent undue restriction, at least in the filter sizes listed.

However, those numbers are for new filters. There is some debate as to whether a used filter is substantially more restrictive.

See: http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=000211;p=5

As to the UPFs, it's my humble opinion that they may actually be superior to the typical paper media filter once in use for awhile. I have a hunch that they won't become as restrictive as paper media filters over time because of the synthetic composition of their filter media.

If I were you, I wouldn't unload my UPFs quite yet. By the way, what size are they?

 

[Gary Allan]

Razl

Please keep in mind that in Grease's filter study the flow is determined at a spec'd pressure. If it had instead been done at a specific flow, we would get a little truer picture of how the filter would work in real life. 5 gpm of flow is 5 gpm of flow.

I wouldn't ditch your filters on ebay.

 

[427Z06]

Razl,

Gary is correct. If your oil pump is generating 5gpm of flow, the engine will get 5 gpm of flow regardless of the filter media because of the oil filter bypass valve (assuming of course the oil pressure doesn't exceed the oil pump bypass valve setting).

Generally, the $200,000 question is how much oil bypasses the media due to filter media restriction. And if it does, is it as bad a situation as some believe. I'm guessing Gary probbaly knows the answer.

 

[Razl]

Thank you guys for the insight 427Z06 and Gary

BTW, the filters are UPF53 which no longer are made. Ironically, this size filter also fits my J.Deere garden tractor as an oversize, though I use SuperTech or Purolators instead.

I have to admit, I'm more confused than ever about real-world wear. UPF claims to reduce wear by 70% because of the better filtration. However, the Flow-Fans says, "Who cares, 70% or more of engine wear occurs at start-up, so flow is key".

 

[T-Keith]

The UPF filters have many other advantages, I would not get rid of them. Grease's study gives an idea of flow but it's not the whole picture. The UPF filter look like great extended drain filters.