OEM filter bypass valve specification

[Coprolite]

Where can I find the OEM specified value for the filter bypass valve for a vehicle? In this specific instance, I am looking for the value for an Infiniti G37. However, I'd like to be able to look this up in the future, also. The owner's manual and FSM lubrication section don't yield any answers.

Thanks!

 

[LoneRanger]

The FSM for my Subaru specifies the filter bypass pressure in the section for the oil pump specs, did you look there in the G37's FSM?

 

[Coprolite]

I will take a deeper probe into the FSM later. Advanced googling yielded a 1 Bar value for the OEM filter, so I will look for independent verification later today. Thanks for the reply.

 

[ZeeOSix]

Why do you need to know exactly?

 

[Ken2]

The engine makers do not publish the specs for their oil filters. The aftermarket filter companies reverse engineer the OEM filters. They either produce a filter that matches their findings, or pick one out of their existing catalog that they feel will be close enough. If an aftermarket oil filter causes damage to the engine, the filter maker covers the damage if you picked the filter they listed in their catalog for your engine.

 

[ltslimjim]

Originally Posted By: Ken2
The engine makers do not publish the specs for their oil filters. The aftermarket filter companies reverse engineer the OEM filters. They either produce a filter that matches their findings, or pick one out of their existing catalog that they feel will be close enough. If an aftermarket oil filter causes damage to the engine, the filter maker covers the damage if you picked the filter they listed in their catalog for your engine.


One reason to not use a 'larger alternate' filter, just pointing that out...use the one each company states is for your vehicle.

 

[dnewton3]

Originally Posted By: ltslimjim
Originally Posted By: Ken2
The engine makers do not publish the specs for their oil filters. The aftermarket filter companies reverse engineer the OEM filters. They either produce a filter that matches their findings, or pick one out of their existing catalog that they feel will be close enough. If an aftermarket oil filter causes damage to the engine, the filter maker covers the damage if you picked the filter they listed in their catalog for your engine.


One reason to not use a 'larger alternate' filter, just pointing that out...use the one each company states is for your vehicle.


That's not a reason not to upsize a filter. Many upsized filters can be found with the exact same delta-P and other criteria.
Example: Wix 51348 and 51516
One can get a better Beta ratio, with all the same physical parameters, assuming one can fit the longer can.

I would agree that one needs to be careful with using "non-specified" filters, but to say it's a reason to not upsize is not correct.

 

[ltslimjim]

Originally Posted By: dnewton3
Originally Posted By: ltslimjim
Originally Posted By: Ken2
The engine makers do not publish the specs for their oil filters. The aftermarket filter companies reverse engineer the OEM filters. They either produce a filter that matches their findings, or pick one out of their existing catalog that they feel will be close enough. If an aftermarket oil filter causes damage to the engine, the filter maker covers the damage if you picked the filter they listed in their catalog for your engine.


One reason to not use a 'larger alternate' filter, just pointing that out...use the one each company states is for your vehicle.


That's not a reason not to upsize a filter. Many upsized filters can be found with the exact same delta-P and other criteria.
Example: Wix 51348 and 51516
One can get a better Beta ratio, with all the same physical parameters, assuming one can fit the longer can.

I would agree that one needs to be careful with using "non-specified" filters, but to say it's a reason to not upsize is not correct.


...Well, I only bring it up because it's more 'work involved' in trying to dispute whether their filter failed or was it your 'wrong' choice of their aftermarket filter which is not specified for your app, even if you can prove some listed specs are the same they may still try to argue, but IDK...not an over-sized user myself, most aftermarkets are larger than OEM Honda filters for my '92 Civic so it's not as big of a deal to me. On the other hand, I'm considering using the PF52s on my parent's 4.3L Chevy engines instead of the PF47s.

 

[Coprolite]

I found it quite curious that different filter makers would have such drastically different bypass values. Wix is on the low end, Purolator matches the OEM pretty much exactly, etc. The variation is quite high.

I would like to stick as close to the OEM bypass as possible but minimize the deltaP.

In the end it is all academic, as I stick to the OEM OCI, so filling up a quality filter is unlikely...

 

[Coprolite]

As we all know, bypass values don't mean anything, as the valve will be open all the time any way.

 

[Garak]

Originally Posted By: dnewton3
Many upsized filters can be found with the exact same delta-P and other criteria.
Example: Wix 51348 and 51516


That's the nice thing about the Wix site. At least if one is going to upsize, one can find the bypass ratings.

Originally Posted By: coprolite
As we all know, bypass values don't mean anything, as the valve will be open all the time any way.


Oh yes, we forgot. Perhaps those of us who don't want it in bypass all the time should cut the dome off and replace the spring with a solid block, and weld everything back together.

 

[dnewton3]

Originally Posted By: Coprolite
As we all know, bypass values don't mean anything, as the valve will be open all the time any way.




What???

I presume you're being facetious?

 

[ZeeOSix]

Originally Posted By: Coprolite
As we all know, bypass values don't mean anything, as the valve will be open all the time any way.



This must be QuadDriver's sock puppet or his cousin.

At any rate, maybe they can get together as a team and convince everyone that bypass valves on oil filters are always open.

 

[ZeeOSix]

Originally Posted By: Coprolite
I found it quite curious that different filter makers would have such drastically different bypass values. Wix is on the low end, Purolator matches the OEM pretty much exactly, etc. The variation is quite high.


The filter's bypass valve setting is also dependant on the filter's design (mostly the media flow characteristics and strenght) as well as the vehicle application (ie, oil viscosity and max flow rate). The manufature will set the bypass valve opening pressure as high as possible without the pressure differential causing any damage to the filter's media or the vehicle.

Originally Posted By: Coprolite
I would like to stick as close to the OEM bypass as possible but minimize the deltaP.


The bypass valve setting has nothing to do with the deltaP generated across the fitlter - only the oil flow rate and oil viscosity does, and of course the flow resitance of the media.

However, the deltaP across the filter and the bypass setting will determine when the bypass valve opens.

Only way to help reduce the deltaP across the filter is use an oversized filter with more media area, and use the specified oil for the vehicle, and not a heavier oil.

 

[Sayjac]

Originally Posted By: dnewton3
Originally Posted By: Coprolite
As we all know, bypass values don't mean anything, as the valve will be open all the time any way.


What???

I presume you're being facetious?

Yes, based on the recent bypass/flow thread and his responses there, quite certain that he is.

Fwiw, the only bypass/relief valve specs that I've read here that seem to be on the high side are for some of the Subaru's, ~23-24 psi.

 

[Coprolite]

Originally Posted By: ZeeOSix
Originally Posted By: Coprolite
I found it quite curious that different filter makers would have such drastically different bypass values. Wix is on the low end, Purolator matches the OEM pretty much exactly, etc. The variation is quite high.


The filter's bypass valve setting is also dependant on the filter's design (mostly the media flow characteristics and strenght) as well as the vehicle application (ie, oil viscosity and max flow rate). The manufature will set the bypass valve opening pressure as high as possible without the pressure differential causing any damage to the filter's media or the vehicle.

Originally Posted By: Coprolite
I would like to stick as close to the OEM bypass as possible but minimize the deltaP.





The bypass valve setting has nothing to do with the deltaP generated across the fitlter - only the oil flow rate and oil viscosity does, and of course the flow resitance of the media.

However, the deltaP across the filter and the bypass setting will determine when the bypass valve opens.

Only way to help reduce the deltaP across the filter is use an oversized filter with more media area, and use the specified oil for the vehicle, and not a heavier oil.




I was having fun with the always open remark.

Obviously, the first step to minimizing deltaP is to determine the bypass valve value and sealing surface size. Then find the longest filter with the most surface area on the filter. Other variables would be differences in media type, which would be considered later. I would like to keep the bypass value as high as possible to avoid unfiltered oil in the engine...

 

[ZeeOSix]

Simple way to go is to just start with the filter that is specified for your car, then find the oversized filter from the same manufacture, which will usually have the same bypass setting. The oversized filter gives more holding capacity, and also less deltaP.

As I said before, you really can't go just by bypass valve setting and assume one with a higher setting is better than one with lower setting.

 

[Coprolite]

Originally Posted By: ZeeOSix


As I said before, you really can't go just by bypass valve setting and assume one with a higher setting is better than one with lower setting.


I have already found one oversized P1 (14610 and 14612 are the OEM swap and oversize). I would like to keep the bypass to OEM spec or lower to avoid any possible starvation. I was just looking around to see if I can go bigger.

I don't quite get your quote above... As long as the bypass value is less or equal to OEM, all should be good. The one that is closer to OEM would bypass less than one which is lower. This would be better under the assumption of the same filter area and filtration media. The toughest comparison would be between different brands, as too many variables change at one time.

Any resources to compare flow between brands?

 

[ZeeOSix]

Checkout this thread for some ideas.

http://www.bobistheoilguy.com/forums/ubb...399#Post2476399

 

[ZeeOSix]

Originally Posted By: Coprolite

As long as the bypass value is less or equal to OEM, all should be good. The one that is closer to OEM would bypass less than one which is lower. This would be better under the assumption of the same filter area and filtration media. The toughest comparison would be between different brands, as too many variables change at one time.


When comparing different brand filters for the same vehicle (and they all are approx the same physical size), then the bypass setting is probably more dependent on the flow resistance of the media used in the filter.

Example: "Filter A" might produce 9 PISD across the media with 10 GPM of hot oil flow, and "Filter B" might produce 4 PSID with 10 GPM of hot oil flow. Manufacture of Filter A might set the bypass valve to open at 14 PSI, and manufacture of Filter B might set the bypass valve to open at 8 PSI.

Originally Posted By: Coprolite
Any resources to compare flow between brands?


Not many available. Most middle to upper tier filters will flow way more than an engine can flow anyway, and have a pretty small PSID across it in normal use. Here's one example of Purolator testing the actual "PSID vs. Flow" of a PureOne filter.

http://www.bobistheoilguy.com/forums/ubb...451#Post1619451