Oil Filter Bypass

[Monkeymaster]

Sooooooooooo,
Hang with me here, I'll be getting to my B body question, just follow along.
Just did some checking on oil filters for our 08 Aspen 5.7 and 09 Ram 2500 5.7, from the Bosch web site.
They call out a 3334. Went to store and 3334 is about the size of a 3600 style that is for a 3.7 v6 - Jeep.
Last year, I had bout some 3410's, that the in store Bosch Book called out.
These are more along the correct size, like a 16, or short 8.
Looked at bosches website on both, both have anti drain back, both have pressure relief, the 3334 has calls out NO psi, the 3410 calls out like 8 to 14 psi, might be 1 or 2 psi off, but it does give a specific psi around that range
Otherwise the only other difference is the can size, I want to use the larger one, ie more oil, good, less oil bad.

So's I get to thinking, my 69 Charger's 440 oil pressure is like 75 psi on my gauge at start up, and might, might get down to 50 when hot at idle, it is a 1/2" hemi pick up with hemi pan, HP Meldon pump.
So, is ANY of my oil in my 69 440 actually getting filtered using the 8 series oil filters ?
I currently have a Bosch on it, used to run the wix 8 series, until store by me quit stocking them.

Just wondering
Fire away

 

[69Bee]

So, after reading this many times, I think I understand what you are asking. To start off, you are way overthinking this. The low pressure rating is for the oil drainback valve, and in no way impacts the ability of the filter to work when the oil pump is supplying the oil at a higher pressure. Your oil is not bypassing the filter when the engine is running.

 

[beanhead]

Righty-o....your engine oil pressure changing with temperature and/or RPM doesn't affect the filter's operation. That 8-14 psi is the difference between the inlet and outlet of the filter itself. So as the filter gets dirty and plugged up, if it gets so bad that pressure at the inlet is say, 50 and the pressure at the outlet is 40, then the bypass kicks in to prevent restricting oil flow through the system and possibly damaging the engine. At least that's the way I always understood it..

 

[Monkeymaster]

I may be overthinking, and I may be completely wrong, but,
My understanding is the anti drain back is basically a flap that prevents the oil from draining out of the filter, no psi rating, then the relief valve is for when/if the filter material is clogged up, or during cold starts with thick oil, thus opens up at the set psi, to prevent oil starvation.
How does ANY filter, with a bypass that has a lower psi rating than what your oil pump puts out, filter the oil ?
Does it only filter lets say 50% of the oil pumped in, with the other 50% going by the filter material, thru the bypass ?
Lets take a Fram regular filter with the paper gasket and paper/cardboard end cap.
If I put that in my 440 thats putting out 75 psi, wouldn't it just blow through the paper element, if it did not have a relief valve ?
Again I may be wrong, been there before, just don't understand how the relief valve rated at 14 psi holds back, and force filters 75 psi of all the oil ?

 

[Monkeymaster]

So
I googled it and sure looks like not 100% of oil is ever really filtered when you have a lot of pressure and the oil filter has a relief valve.
Interesting

 

[bm02tj]

That is pressure differential across the filter media
not pressure of the oil in system