Oil Filters - UTG video, lets discuss (filtration&bypass flow)

[figjam]

This bloke should be employed in Canberra as a political adviser to a senior Gubbermint Minister.
"I stuffed up by not making myself clear in what I actually said, so I will make up a word salad to explain my mistake, which you should have understood what I really meant anyway. "

 

[Immortality]

I do like UTG, he puts everything out there and can admit when he's got something wrong. Very upstanding guy.

I'm gonna post the video on the video of the day thread as well so there is some continuity in that thread too.

 

[J_D 2.0]

A good Automotive video that should put the cat amongst the pigeons!

Read the comments after, the truth is to be found there (pressure differential)

This here is a good reason to not run a high pressure oil pump on a normal road car. The oil filters are made for stock oil pressures and if you upgrade your oil pump to a higher pressure then your probably running your oil filter on bypass 100% of the time.

 

[Immortality]

Although true, a lot of modern engines run high pressure pumps. Our little V6 motors see ~40psi idle oil pressure (on a healthy motor). I've seen almost 80psi cold start oil pressure on my old V6. A lot of that oil isn't going through the filter

On my old V6 that would see ~80psi cold oil pressure I did run a remote oil filter mount with a Ryco Z9 size oil filter which has probably 3 to 4x the filtration area of the standard Z154 filters.

 

[J_D 2.0]

Although true, a lot of modern engines run high pressure pumps. Our little V6 motors see ~40psi idle oil pressure (on a healthy motor). I've seen almost 80psi cold start oil pressure on my old V6. A lot of that oil isn't going through the filter

I’d dare say that most of the oil doesn’t go through the filter at startup on nearly every car as cold oil pressure is quite high.

Most engines now have higher oil pressures to run the variable valve timing, displacement on demand etc. Probably not much of an issue as the standard oil filter is designed to work with the OEM pressures. I think the potential problem comes in when you put an aftermarket high pressure oil pump on, then you are running a higher pressure than the OEM pump which is higher than what the spin on filters were designed for.

If the standard oil filter is made with a pressure release valve for say 20psi because the OEM pressure is a bit below that at idle and you change to a high volume/pressure pump that bumps it up to 30psi at idle your now bypassing the filter (for at least a part of the oil volume) 100% of the time.

 

[Immortality]

Problem is cold start is the worst time to have oil bypass the filter.

The bypass systems don't work on an absolute pressure, they work on pressure differential, If the pressure drop across the filter is greater than the bypass valve spring then it will open.

 

[Skylarking]

Yes, UTG got it wrong… both times…

The anti drain valve simply stops the oil draining from the oil galleries back into the oil filter can and then back into the sump over night. If such drain back occurs then such would cause a dry start condition when the engine is next cranked which isn’t great (cause assembly lube only lasts so long ).

The spring at the bottom of the filter media is there to seal the upper part of the media cap centre bore against the ant drain valve thus it stops oil entering the oil outlet at the top of the filter as UTG suggests. The oil can only enter the outlet port via passing through the filter media itself or via passing through the bypass valve at the bottom of the filter media. Which path the oil takes depends on oil viscosity and/or pressure. And the filter media doesn’t move up and down on the spring because of the way oil pressure surrounds the whole media…

The filter will go into bypass on cold start but as the oil gets more fluid the bypass valve will close and the filter media will do its job unless oil pressure is too high due to blocked filter media (hasn’t been changed for ages) or wrong oil viscosity (rtfm) or a new high volume high pressure oil pump (which the bypass valve isn’t calibrated for).

Unfortunately there isn’t a video that discusses all aspects but I previously posted the following in the VOTD thread earlier today.

The anti drain back flap is not part of the filter bypass system and the filter media can never slide rearwards because pressure would be pressing on it from all directions.

Here’s how a filter works, first video is how the bypass works and second describes the anti drain flap.

mod edit: I've created a separate thread here for discussion on this topic.

The following also goes into some aspects…

Really, the filter won’t always filter 100% of the oil flow coming from the pump and that is by design. Just wish they had a oil filter differential pressure sensor and a idiot light and/or DTC and check engine lamp to remind the less mechanically concerned that they need to change their oil filter… Such is QED but meh, save a few cents per engine is better…

PS: I don’t ever remember seeing an oil filter spec define the bypass pressure setting of the oil filter bypass itself in any of the advertising or spec sheet where oil filters are purchased. So one does have to wonder what goes on with engines whose pumps have been upgraded? 50% oil volume filtration?

 

[Immortality]

This is the other option for full filtration, bypass oil filtration.

https://www.amsoil.com/p/universal-dual-remote-bypass-system-bmk23/?code=BMK23-EA

This one is bloody expensive though and it doesn't even come with the filters required.

 

[Immortality]

Really, the filter won’t always filter 100% of the oil flow coming from the pump and that is by design. Just wish they had a oil filter differential pressure sensor and a idiot light and/or DTC and check engine lamp to remind the less mechanically concerned that they need to change their oil filter… Such is QED but meh, save a few cents per engine is better…

It is by design but it doesn't need to be. Simply fitting a larger filter with more filter media means there is less pressure drop across the filter, more filtration and less bypass.

To quote from the website I linked earlier

We have run static pressure tests between our filters and paper filters for an identical application. For the same sized filters, our stainless steel micronic filter consistently flowed over 7 times more oil for the same time period than did the paper filter (tests were run at 68 degree ambient temperature). How does this affect what is going on inside your engine? We installed pressure gauges on each side of the filter element on a pro stock drag race engine so we could measure differential pressures (the difference in pressure between the input side of the filter element and the output side of the element). During a full pass down the strip the differential pressure of the stock paper filter measured 20psi difference. Our filter measured less than 1psi difference. Less differential pressure means less chance of bypass operation, faster oil pressure at start up, less drag on the oil pump (potential horsepower gains) and higher flow through the engine, often helping to cool the oil and keep the crankcase cleaner.

FAQs – K and P Engineering

kandpengineering.com

 

[Skylarking]

It is by design but it doesn't need to be. Simply fitting a larger filter with more filter media means there is less pressure drop across the filter, more filtration and less bypass.

If engineers had full control, the oiling system would be much better. Sadly acountants not only look at manufactuting cost, I'm sure they also consider maintenance cost and dealer profits (else dealers want to sell their cars).

And if the manufacturer designed a much larger higher flowing filter with greater crap entrapment capacity and a differential pressure sensor that would flag when the filter needed to be changed, what would the service deoartment do to justify their $350 capped price service (which is jyst an oil change and cursory look over)...

As is, GM reprogramed their engine oil life system in the USA as the engineered algorithm wasn't sending the owner to the dealer frequent enough and the dealers complained so a non engineering required change was made to appease the dealers