Position of the By-Pass Valve in an Oil Filter

Originally Posted By: Baracoa
Additional information received from Royal Purple technical support concerning any alleged disadvantage to filters with a dome-end bypass valve indicated the following:

The reality however is that there is no meaningful difference in the quality or cleanliness of oil that by-passes at the top or the bottom of the filter cartridge.


Unless the filter is positioned like in the Motorcraft graphic I posted earlier, and there was all kinds of crud/sludge laying in the dome end of the filter next to the bypass valve.

Just keep the guts of your engine clean and that will alleviate any concern about the location of the bypass valve.
 
Originally Posted By: Baracoa
Quality is usually associated with a higher cost whether it's related to oil filters or any other products. Royal Purple filters are more expensive than other brands that offer lower quality filters intended for shorter oil change intervals. K&N and Mobil 1 are of similar quality and price to Royal Purple. Investing an extra $5 to $10 dollars in a more reliable and higher quality filter is worth it compared to the potential risk and damage that a cheap oil filter can cause. Don't settle for less when protecting your car's engine.


Fram Ultra is a better choice.
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Originally Posted By: ARCOgraphite
Main problem I see with base end bypass is that the unit displaces volume which would be better utilized by pleated media area in the small "hamster sized" form factors so prevalent today. One reason I run a Titan v8 filter on my Rogue. engine is still silly noisy during dead cold warmup.
That is because it is cold and the oil drains out of the oil passages cam tensioners etc !
 
Quote:
....To note, Ford uses both relief valve designs in their product line.

I believe you'll find that those intended primarily for FoMoCo applications MC uses a thread end bypass combined with majority silicone adbvs. As they also make filters for use on other makes, those generally use dome end bypass, and likely nitrile adbv.

I will use either and don't consider it a big deal one way or the other. Best information says bypass is relatively infrequent and short duration event anyway. In a well maintained engine either should work fine.
 
We know Fram has positions here, they pay in cases of filters I heard. Contact RP direct or through their lead man here? I would like to get some cases of those to try.

So if my filter points base down, dome end bypass is the way to go? Or buy a GM car with no bypass in the filter is maybe best.
 
Get the filter recommended by your car maker or any other high quality filter that is an exact fit for your car. If your original equipment requires a by-pass in the oil filter, then that is what you need to install. Filters that fit your vehicle, regardless of brand, should come with a by-pass valve.
 
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Quote:
.....Filters that fit your vehicle, regardless of brand, should come with a by-pass valve.

Unless the engine has an engine block bypass, in which case none is spec'd or required for the filter. Many older GM and some other makes have block bypass.
 
Observe the thin carbon layer on the bypass leaf and associated garbage in the the valve area itself.

This is what baked on and migrated to this part of the filter after 15K and 2 OCI's.

It isn't hard to guess that during a bypass operation some measure of the detritus is making its way into the engine.


UD

 
Royal Purple offers the RP 20-500 with a dome-end bypass but the RP 10-2835 has a thread-end bypass.
5/2021 update, my order of QTY(4) RP 10-2835 had bypass valves located at the dome end. Box and online images may not have updated from prior design. Just a heads up on my experience, search goes on...
 

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thread-end bypass is always better because the oil isn't washing over the filter media and flushing larger particles into the engine like can happen with dome end bp.

and the ultra has better filtering specs then rp
 
thread-end bypass is always better because the oil isn't washing over the filter media and flushing larger particles into the engine like can happen with dome end bp.

In the event that a bypass event would be triggered the oil pressure would be forcing the particulate matter against the media, would it not?

I use Wix filters with the thread end bypass but not because of what you expressed. I have heard that said repeatedly but I don't consider it to be a meaningful concern.
and the ultra has better filtering specs then rp

Recent testing has shown that the Ultra has better flow as well. Royal Purple's can strength and burst pressure is second to none though.
 
In the event that a bypass event would be triggered the oil pressure would be forcing the particulate matter against the media, would it not?
I would say some.... But your still going to have some flush particles because of the high flow towards the relief.
I've opened filters and seen lots of carbon at the dome end and nothing at the threads
I use Wix filters with the thread end bypass but not because of what you expressed. I have heard that said repeatedly but I don't consider it to be a meaningful concern.


Recent testing has shown that the Ultra has better flow as well. Royal Purple's can strength and burst pressure is second to none though.
 
I would say some.... But your still going to have some flush particles because of the high flow towards the relief.
I've opened filters and seen lots of carbon at the dome end and nothing at the threads

I will have to agree with you while qualifying my agreement by saying that it depends on how your can filter is mounted. See my thread on the Fram 9688 from my Hyundai linked below. That filter is mounted threads up so it is constantly filled with oil and apparently much of the gunk it in settles in the dome end when the engine is off. OTOH my Subaru engine has the filter mounted threads down so naturally I would be inclined to believe that the gunk would settle on the ADBV upon engine shutdown and end up getting pressed against the media upon startup.

 
I will have to agree with you while qualifying my agreement by saying that it depends on how your can filter is mounted. See my thread on the Fram 9688 from my Hyundai linked below. That filter is mounted threads up so it is constantly filled with oil and apparently much of the gunk it in settles in the dome end when the engine is off. OTOH my Subaru engine has the filter mounted threads down so naturally I would be inclined to believe that the gunk would settle on the ADBV upon engine shutdown and end up getting pressed against the media upon startup.


Maybe..All I can tell ya is what I'm seeing, most if not all carbon deposits/gunk with a dome end bp I see is congregated at the dome end, all my filters are threads up but imo it doesn't matter where the threads are up, down, sideways some deposits are going to fallow flow especially as media becomes more loaded.
 
How long do people here figure a PRV even stays open if one does ever open at all ?
Not sleepless over this one …
 
thread-end bypass is always better because the oil isn't washing over the filter media and flushing larger particles into the engine like can happen with dome end bp.

and the ultra has better filtering specs then rp
Always? So on my Subaru that has the base plate "thread-end" mounted down, wouldn't this contradict your statement? I agree with a filter mounted base plate up, it is better. A filter mounted horizontal? Probably doesn't matter. But I personally can't imagine a filter full of sludge and dirt that would actually matter. Not on anything I own.
 
Always? So on my Subaru that has the base plate "thread-end" mounted down, wouldn't this contradict your statement? I agree with a filter mounted base plate up, it is better. A filter mounted horizontal? Probably doesn't matter. But I personally can't imagine a filter full of sludge and dirt that would actually matter. Not on anything I own.

IMO yes... like I said it don't matter what direction the TE is facing the rush of oil is going to flush some carbon towards the BP so even down like on your Subaru with help from gravity it'll happen. Ive seen it on a lawn mower ford 910s filter mounted sideways.

I've opened hundreds of filters my own and at work I see where the $hit is heading.
 
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