Does relief valve PSI matter much?

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This might be a really dumb question, so I apologize in advance if it is! I have a few of the Purolator 14610 (Wix 1356/Fram 7317 size) filters for my Acura that recommends the Purolator 14459/Wix 1334/Fram 3593A. It has the same gasket and thread and it fits fine. I've noticed that with the Wix 1334 and 1356 they have the same relief PSI (8-11psi). But Purolators are 12-15 psi for the 14459 whereas the 14610 is 14-18 psi. Is this important, and should I pass on using the 14610? I find it odd that the 14610 which cross-ref's to the Wix 1356 has a different relief PSI... Just in case I worded it poorly, here's a break-down of the filter relief PSI's for the filters I have: Recommended size on left, newer/alternate size on right: Fram PH3593A (12 PSI) compared to Fram PH7317 (13 PSI) Wix 1334 (8-11 PSI) compared to Wix 1356 (8-11 PSI) Purolator 14459 (12-15 PSI) compared to Purolator 14610 (14-18 PSI) And the question in a nut-shell, is running the newer/alternate size of the Fram or Purolator (with differing Bypass specs) going to harm anything? I've ran both the 1334 and 1356 already, but since they have the same setting I didn't notice any difference in performance. Thanks in advance
 
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I think in the case of an Acura, the higher bypass may just be because the media can stand up to a greater pressure. The oversized Amsoil filter I run has a bypass that's substantially higher than the factory filter and no problems in over 70,000 miles.
 
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 Originally Posted By: ThirdeYe
I have a few of the Purolator 14610 (Wix 1356/Fram 7317 size) filters for my Acura that recommends the Purolator 14459/Wix 1334/Fram 3593A. It has the same gasket and thread and it fits fine. I've noticed that with the Wix 1334 and 1356 they have the same relief PSI (8-11psi). But Purolators are 12-15 psi for the 14459 whereas the 14610 is 14-18 psi. Is this important, and should I pass on using the 14610? I find it odd that the 14610 which cross-ref's to the Wix 1356 has a different relief PSI ...
IMO, the higher the bypass setting the better. I means that the filter will have to get more loaded to go into bypass mode. It also means the filter can take a larger PSID (due to thicker oil or high volume oil pump) before going into bypass mode. Subaru specs a 23 psi bypass setting due to high volume oil pumps. A filter may also have a slightly higher bypass setting due to it's flow restriction being a little more than the next filter. The bypass setting is part of the overall design of the filter as a system. The oil flow volume, viscosity and media restriction and loading factors are part of the equation to determine the bypass setting. If it was my car, I'd run the 14610 with no worries since the bypass setting is a little higher than the 14459.
 
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I think it is just the compromise the engineers choose between cleanliness and flow. I would go with the American owned and thread end Wix.
 
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Good discussion. What about the other way? I bought a new design Fram XG3614 for my Mazda 2.3, that has a relief PSI of 12. The Bosch 3330 that I usually use has a 14 PSI relief...........Anybody see any issues here?
 
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Yea it could go into bypass sooner/easer,,not what you want. Stick with the Bosch over that FRAM-O-Death man!!
 
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So, if I start using a Ford Racing filter instead of the regular Motorcraft FL 820S, the racing filter's much higher bypass pressure only means that more of my oil gets filtered before it opens? In practical terms, for a street v6, does it take a WOT before it opens (assuming its not clogged)?
 
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 Originally Posted By: SHAMUS
So, if I start using a Ford Racing filter instead of the regular Motorcraft FL 820S, the racing filter's much higher bypass pressure only means that more of my oil gets filtered before it opens? In practical terms, for a street v6, does it take a WOT before it opens (assuming its not clogged)?
The racing filters are designed for use on high volume oil pumped engines running at high RPM with relatively thicker oil than a street car. If you used the racing filter on a street car with a stock oil pump, it probably would never (or very rarely) go into bypass mode if the filter stayed pretty clean.
 
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 Originally Posted By: D Bone
Good discussion. What about the other way? I bought a new design Fram XG3614 for my Mazda 2.3, that has a relief PSI of 12. The Bosch 3330 that I usually use has a 14 PSI relief...........Anybody see any issues here?
A few psi one way or the other is probably OK as I'm sure there is some headroom in the bypass design setting. One good example of what not to do, and a hot topic a while ago, was using a filter with a 8~10 psi bypass setting on the high volume oil pumped Subaru that specs a 23 psi filter bypass setting. In a case like that, you'd surely see more often and longer bypass events of the filter which could send debris down into the engine where is shouldn't be.
 
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First problem in comparison is that when they print one number, you don't know whether it is when it starts opening or when it is open all the way. If it says 8-11, it starts opening at 8 and is totally open at 11. Nor do you know, without cutting it, what the valve size is (they vary greatly. But you do not want to stray far from the original spec. If it calls for 8-11 and you put 23 in it, you will probably run dry for certain periods. It is probably an engine that needs to get oil without building a 23 psi differential. If it calls for 23 and you put 8-11, you will always have oil, but more dirt will circulate without filtering. In cold starts you will frequently be in by-pass. I recently asked a Donaldson tech friend about the options for my Corvair, since I've put an adapter on it to use a normal 3/4" filter and the block has its own relief valve at 10psi. He recommended that I limit y choices to those that are close to the block pressure (10 psi) since that valve could fail and the valve in the filter serves as a secondary relief.
 
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 Originally Posted By: widman
But you do not want to stray far from the original spec. If it calls for 8-11 and you put 23 in it, you will probably run dry for certain periods. It is probably an engine that needs to get oil without building a 23 psi differential.
You are making that statement based on the assumption that a filter with a 23 psi bypass setting is MUCH MORE restrictive than one that has a 11 psi setting. That is not necessarily the case. It could be a factor, but IMO the filters with a higher bypass setting are mainly because the application is a car that runs a high volume oil pump and/or thicker oil. That's what is causing a higher PSID across the filter, and what warrants a higher bypass valve setting.
 Originally Posted By: widman
If it calls for 23 and you put 8-11, you will always have oil, but more dirt will circulate without filtering. In cold starts you will frequently be in by-pass.
That's true, and I stated that someplace above. For instance, you DO NOT want to put a 8~11 psi bypass filter on an engine that is specifying a 23 psi bypass filter - like the Subarus with a 12 gpm oil pump. The high oil volume going through the filter will easily get the bypass valve to open in that case - especially with cold oil and during warm-up, and maybe even at high RPM with hot oil.
 
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 Quote:
You are making that statement based on the assumption that a filter with a 23 psi bypass setting is MUCH MORE restrictive than one that has a 11 psi setting.
No, I'm making the assumption that the rest of the filter is the same, as is very often the case, at least to the eye when cut open.
 
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 Quote:
Recommended size on left, newer/alternate size on right: Fram PH3593A (12 PSI) compared to Fram PH7317 (13 PSI) Wix 1334 (8-11 PSI) compared to Wix 1356 (8-11 PSI) Purolator 14459 (12-15 PSI) compared to Purolator 14610 (14-18 PSI)
Interesting that Fram just guesses at one number....... Also, the two Donaldson crosses for those are P502007 and P550162 start opening at 11 and finish at 17. The P550162 is designed for Honda (and Isuzu), with a 99% efficiency at 39 micron verses the nominal ratings for the other. Without specific information to the contrary from Honda, I'd go with the filter that isn't just a cross, and use the 11-17 as a good number. I'd also go with the 99% efficiency of 39 vs the lesser filtration. (no, I don't know what the nominal rating is)
 
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From what <i>i've</i> seen filters/media is the same("'s and thickness)a higher bypass on a given engine would stress the media more force more oil through it as it's getting plugged,less likely to go into bypass upon cold starts etc, but if a filters of good quality with a nice center tube i don't see a problem. I run a higher bypass my self on things,media always looks fine upon inspection.
 

ThirdeYe

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This might be a very primitive way of thinking, but I think I will run the 14610 with the higher PSI bypass setting in the summer and the lower bypass settings, like the Wix in the winter. Does that sound logical in an area that gets well below freezing in the winter?
 
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 Originally Posted By: ThirdeYe
This might be a very primitive way of thinking, but I think I will run the 14610 with the higher PSI bypass setting in the summer and the lower bypass settings, like the Wix in the winter. Does that sound logical in an area that gets well below freezing in the winter?
well if using the right oil(thin for winter) you could get away with running the 14610. dont let that stop you.
 

ThirdeYe

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 Originally Posted By: daman
 Originally Posted By: ThirdeYe
This might be a very primitive way of thinking, but I think I will run the 14610 with the higher PSI bypass setting in the summer and the lower bypass settings, like the Wix in the winter. Does that sound logical in an area that gets well below freezing in the winter?
well if using the right oil(thin for winter) you could get away with running the 14610. dont let that stop you.
I typically run 5W-30 year round.
 
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