Flow vs. Filtration

[PROJECTCAR]

I was curious what everyone's thoughts were regarding flow vs. filtration. I would venture to say that generally you would want to achieve the best balance of the two. When researching various filters it becomes difficult for me to come to a conclusion. With so many different filters available in 20x1.5 (still keeping the maximum od of the gasket in mind) i am overwelmed with options. How often does a filter actually go into bypass? If a filter has a lower psi by pass will it go into bypass mode more often than one with a higher psi? If so, choosing a filter with a higher bypass will lead, in theory, to greater filtration given all others constant correct? If this is correct i would gather that there is a possible sacrifice of flow to vital engine parts. Please provide any thoughts you may have to help me make a more educated decision.

 

[river_rat]

1. Well, the filter usually isn't much of the total flow resistance--the bearings and engine oil galleries are. At least until the filter plugs up.

2. Back in the 50s, Ford did tests with full-flow oil filters and engine life due to wear was immensely lenghtened--like doubled. That was with some probably pretty primitive filter media compared to what we have nowadays.

3. People use all sorts of cheapo filters and bulk oils and still get 200-300K miles out of their cars and trucks.

4. All filters have to meet certain minimum SAE filtration standards.

Feel better?

Having said all that, I go for an oversized (usually) filter for which I can get info on.
Amsoil EaO, Purolator (and PureOne), and WIX, give you actual test data.
Mobil 1 does not give the micron size for which it gets its 99.2% efficiency rating.
Fram just says XX% at >20 microns--that could mean anything.
Baldwin show reasonably respectable efficiency numbers similar to WIX. They give this info if you email them and I posted some on this site.

Bottom line, IMO, you can only go so wrong with any well constructed filter, but as far as the efficiency part goes, if a manufacturer doesn't give out the info, you have to ask yourself why they don't want you to know.

My 2 cents.

 

[Captain_Klink]

I use the one with the biggest or longest can, that will fit.
that way you maximize flow and filtration. buy a good filter, like purolator pure one, or napa gold, or bosch, or even supertech is not a bad filter (too cheap for my taste though, i don't like to risk my engine for a couple of measly bucks). following these rules, change oil every 3000 miles, using any bargain brand oil, of the correct viscosity (usually 5w30, sometimes 5w20 SM) and change filter every second time, the engine will probably go 300,000 miles and still be good.

 

[river_rat]

The Captain raises a good point--all other things being equal, the slower flow through the bigger filter element increases efficiency--catches more particles. (To a point of course)

 

[Spector]

Since filters really capture very little (most particles way too small to be captured by full flow filters) and modern engines really spew out very little I go with flow over filtration any day.

 

[PROJECTCAR]

I originally was going to use an oversized filter. However, my research found that the beta ratios of the larger filters were typically not as good. For example wix 51356 has a beta ratio of 2/20=6/19 and its larger counterpart 51344 has a beta ratio of 2/20=22/40. Another example using the pureone is the PL14459 being 99.9% efficient at 20 microns and the larger PL14610 is only 99.9% effiecient at 40 microns. Correct me if im wrong but i dont exactly expect better filtration from these larger filters.

 

[ryland]

I like to use the OEM filters because I'm guessing the flow to filter ratio has already been thought of by someone who knows more about the motor than me. I've been stuck on useing them after getting start up noise from some pretty popular filters on this site and no noise from the OEM. So when it comes to oil filters OEM is all I ever buy.

 

[Eddie]

+1 ryland. I too guess that the company has decided on several parameters including the pressure relief settings.

 

[river_rat]

Originally Posted By: PROJECTCAR
I originally was going to use an oversized filter. However, my research found that the beta ratios of the larger filters were typically not as good. For example wix 51356 has a beta ratio of 2/20=6/19 and its larger counterpart 51344 has a beta ratio of 2/20=22/40. Another example using the pureone is the PL14459 being 99.9% efficient at 20 microns and the larger PL14610 is only 99.9% effiecient at 40 microns. Correct me if im wrong but i dont exactly expect better filtration from these larger filters.

Apparently in your applications--the part numbers you use--you are right.
I usually find that it works the other way on the filters I use.
Medias being equal, the lower the face velocity of the liquid, the more it should be filtered better.