Oil filter size

[cudabob496]

Read that todays engines use a small oil filter, so engine can build oil pressure
faster at startup.  Guess I'll go to the smaller K&N from now on, on my 496.

[Cuda Cody]

I've always found that my old mopar engines make almost too much oil pressure.  They are known for being great at producing strong PSI numbers for oil pressure.  At start up (cold oil) these classic engines can produce 70 to 80 psi pretty easy.  And when warm they seem to be around 60 psi while driving.  Not sure I want any more then that as it could be hard on seals. 

Do you think you 496 will have low oil pressure?  I would stick with a standard oil filter (any of the quality name brands) and see what your oil pressure is before looking to change the size in an effort to increase the psi.   

[RUNCHARGER]

Interesting theory. I have always used the longest filter I could fit on there so I had as much filtering area as possible.

[cudabob496]

I've always found that my old mopar engines make almost too much oil pressure.  They are known for being great at producing strong PSI numbers for oil pressure.  At start up (cold oil) these classic engines can produce 70 to 80 psi pretty easy.  And when warm they seem to be around 60 psi while driving.  Not sure I want any more then that as it could be hard on seals. 

Do you think you 496 will have low oil pressure?  I would stick with a standard oil filter (any of the quality name brands) and see what your oil pressure is before looking to change the size in an effort to increase the psi. 

yep, the 70 to 80 psi numbers, and 60 when hot, are what I'm seeing now.  But given the fact that most engine wear occurs at startup, a smaller filter would mean even more oil pressure sooner I would think, due to there being less filter material present. May mean I should change the smaller filter more often.  Using full synthetic also means quicker oil flow at startup as well. The oil filter on my friends 09 Subaru Forester is almost tiny, like 2/3 of a cup.

[cudabob496]

Interesting theory. I have always used the longest filter I could fit on there so I had as much filtering area as possible.

me too, but changing a small filter more often may be worth it, if it means less engine wear at startup. More filter material
means more filtering before filter clogging, but also means more restriction to oil flow at startup, I guess.

[cudabob496]

I've always found that my old mopar engines make almost too much oil pressure.  They are known for being great at producing strong PSI numbers for oil pressure.  At start up (cold oil) these classic engines can produce 70 to 80 psi pretty easy.  And when warm they seem to be around 60 psi while driving.  Not sure I want any more then that as it could be hard on seals. 

Do you think you 496 will have low oil pressure?  I would stick with a standard oil filter (any of the quality name brands) and see what your oil pressure is before looking to change the size in an effort to increase the psi. 

yes, not wanting to change psi. Wanting to shorten time for pressure to build at startup.

[cudabob496]

https://www.bobistheoilguy.com/forums/ubbthreads.php?Number=2117431&ubb=showflat

[7212Mopar]

More surface area should have less pressure drop but it does take longer to fill a bigger volume.

[cudabob496]

once full, I assume the filter stays full.

more surface area should mean more resistance to flow, so
a larger pressure drop?

[Jim AAR]

Almost ALL Cartridge oil filters have an Anti-Drainback valve made of Rubber or Nitrile that keeps the oil in the filter when it is not running. That's why you can never drain all of the oil from a filter when you remove it, unless you puncture this seal.

Some may drain out, but it should not be enough to affect the Oil Pressure significantly. And if some does drain out, I would think that having a larger filter would be the safest way to go.

If you are worried about it, don't rev your engine on startup, let it warm for a couple of minutes before you put any load on it.

I always use the recommended Oil Filter for the engine account the hours (in the many thousands under all conditions (Warm/Cold/Humid/Dry), different loads and startup procedures) of testing that an engine is subject to by the manufacturer would weed out any issues. Too me this is like trying to rebuild the wheel when it is already made and rather pointless.

There is definitely more testing done by an engine manufacturer on their engines than any engine builder would ever do.

My 

[7212Mopar]

Larger surface for the same amount of flow reduces average oil velocity across the media thus less pressure drop. Also larger surface has more dirt holding capacity. Flow will not increase because the oil pump is positive displacement.

[cudabob496]

Larger surface for the same amount of flow reduces average oil velocity across the media thus less pressure drop. Also larger surface has more dirt holding capacity. Flow will not increase because the oil pump is positive displacement.

gotta disagree. for same volume flowrate, the more filter paper the oil interacts with, the greater
the pressure drop.  If you were to slowly reduce the amount of filter paper, until no filter paper, the
dp would decrease until zero.

[dodj]

Larger surface for the same amount of flow reduces average oil velocity across the media thus less pressure drop. Also larger surface has more dirt holding capacity. Flow will not increase because the oil pump is positive displacement.

gotta disagree. for same volume flowrate, the more filter paper the oil interacts with, the greater
the pressure drop.  If you were to slowly reduce the amount of filter paper, until no filter paper, the
dp would decrease until zero.

Larger filter area, less drop. Bob, your theory is flawed. The larger the area, the less volume of oil has to be forced across a certain area of filter. =less drop.

7212 has it right.

[cudabob496]

then why does pressure build quicker with a smaller filter?
oil pump is positive displacement.

[dodj]

then why does pressure build quicker with a smaller filter?
oil pump is positive displacement.

Pressure = force/area
Reduce the area (filter media)  for the same amount of force (pump output) and pressure (before the filter)will go up.
Does pressure after the filter build faster with a smaller filter? Nope. Unless it is a different design of filter than the larger one you are comparing with.