Bypass valve size and spring force important?

Messages
370
Location
Munich, Germany
Gentlemen,

is the setting and size of a bypass valve important? Or is it just "randomly" set by the manufacturer?
The Oilfilter from Honda for the S2000, part Number 15400-PCX-004 has a bigger sized bypass valve (20 mm / 3/4" Diameter) and the spring is stiffer than usuall. The S2000 Engine have a little bit higher than usuall Oil pressure, up to 7 Bar / 100 PSI.

Here is a comparison of some filters, including the Bypass Valve:

Aftermarket filters mostly have smaller sized bypass valves, most are in the 10mm / 3/8" diameter range.
Some people say the setting of the spring and size is not important, some peoply say it is highly important.

I am a little bit confused.
 
Messages
25,787
Location
PNW
The bypass valve's spring constant (ie, spring stiffness) is matched to the size of the bypass valve to make it open at the specified bypass pressure setting.

When a bypass valve opens, only a portion of the oil flow goes through the bypass valve. So the diameter of the bypass valve doesn't have to be huge. Only time a bigger diameter bypass valve would be useful is if the filter was 100% clogged, but it should never get to that point unless a vehicle is totally mistreated and not ever maintained.

Trust the filter designers.
 
Messages
1,878
Location
Americus, GA
I believe that I’ve seen a similar thread on here about Honda S2000 filters. Here’s the bottom line. The S2000 filters require a higher bypass setting than a standard Honda 2.0 or 2.4 engine. Every filter manufacturer has a certain way of meeting that specification. As long as your filter meets the S2000 requirement, you will be fine.
 
Messages
1,967
Location
USA
Aftermarket filters mostly have smaller sized bypass valves, most are in the 10mm / 3/8" diameter range.
Some people say the setting of the spring and size is not important, some peoply say it is highly important.

I am a little bit confused.

Don't be, you can read Z's answer above and that's pretty much the Alpha and Omega on the subject.

You will find that depending on the vehicle and filter OEM- they may use a spring relative to a specific vehicle pressure or a standard multi range spring ( keeps down the SKU's for the wire they are made from)
 
Messages
3,133
Location
Western S.C.
Opening bypass pressure depends on spring force as installed, divided by effective valve area acted on by the oil pressure difference---not on either spring constant or valve size alone.

Don't worry about it!
 
Messages
21
Location
Switzerland
I think this one may fit your car?
Made in Germany, been using these forever on my K24. Whem I found this offer I bought a dozen...
 

ChristianReske

Thread starter
Messages
370
Location
Munich, Germany
Thank you for the hint.
MANN say that the 610/6 will fit the S2000, but the S2000 has a bad reputation for vibrating oil filters loose. Because of this, Honda recomends only the 15400-PCX-004 filter for the S2000, to wich the MANN filter W811/80 is almost identical.
It has a total different gasket design with a "P" shaped rubber seal and should be tightened almost 1 full turn to avoid comming loose.

In the german Honda S2000 forum are some reports about filters that get loose when the mechanic was careless and only "Hand thigtened" it or non-Honda oil filters where used.... in the worst case engines could catch fire.
Wich filter to use and the size of the filter is a VERY controversial topic among Honda S2000 Owners. ;)

Saying this, i have used the MANN 610/6 often on my previous CRX del Sol without any problems.
 
Messages
25,787
Location
PNW
MANN say that the 610/6 will fit the S2000, but the S2000 has a bad reputation for vibrating oil filters loose. Because of this, Honda recomends only the 15400-PCX-004 filter for the S2000, to wich the MANN filter W811/80 is almost identical.
It has a total different gasket design with a "P" shaped rubber seal and should be tightened almost 1 full turn to avoid comming loose.

If you're worried about the filter coming loose, then get a hose clamp and some safety wire and do something like shown in the photos.

Oil Filter safety Wired-1.jpg


Oil Filter safety Wired-2.jpg
 

ChristianReske

Thread starter
Messages
370
Location
Munich, Germany
Thats the reason why you dont heard about this problem...
Honda has adressed this problem about 15 Years ago with the special 15400-PCX-004 Filter. It requries 7/8 Turn or 15-18 Lb/ft to avoid comming loose. This filter is exclusive for the S2000, for a reason. Every S2000 Owner is aware if this problem. Ask your friends WHY they are only using the OEM Honda Filter. There are numerous discussions and reccomendations about this problem in S2000 and Honda Forums, do a Google search if you dont belive me. :)
 
Messages
25,787
Location
PNW
Thats the reason why you dont heard about this problem...
Honda has adressed this problem about 15 Years ago with the special 15400-PCX-004 Filter. It requries 7/8 Turn or 15-18 Lb/ft to avoid comming loose. This filter is exclusive for the S2000, for a reason. Every S2000 Owner is aware if this problem. Ask your friends WHY they are only using the OEM Honda Filter. There are numerous discussions and reccomendations about this problem in S2000 and Honda Forums, do a Google search if you dont belive me. :)
The Honda OEM filter has a P-gasket, and the torque spec Honda calls out will bottom out the can base on the engine mount (and then more slight tightening from there) which helps keep the filter from coming loose.
 

ChristianReske

Thread starter
Messages
370
Location
Munich, Germany
Yep, exactly. Although i never had the feeling that the filter bottomed out when i installed it and torqued it down. However, i allways needed a good "Oomph" with the ratchet to loose it at the next change. It works.

In Contrast, there are some reports in the german S2000 community about filters that come loose because they where only
thigthened by Hand "as allways.." or non Honda filters where used. If you are lucky, you only spill oil, if not you need a motor or you car catches fire.

So much for "It´s just a oil filter...easy task!"
 
Last edited:

JT20

$50 Site Donor 2021
Messages
3,674
I believe that I’ve seen a similar thread on here about Honda S2000 filters. Here’s the bottom line. The S2000 filters require a higher bypass setting than a standard Honda 2.0 or 2.4 engine. Every filter manufacturer has a certain way of meeting that specification. As long as your filter meets the S2000 requirement, you will be fine.

Having a similar issue on the EJ.

They need it set higher...
 
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