Filters with same thread and gasket- different bypass values

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Sep 20, 2024
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New guy, asking because I'm not entirely clear on the bypass function. I did search here & didn't see a clear answer to this question. I had a Subaru that used 20x1.5 thread filters with a bypass rating around 23 PSI, sold the car, still have some filters. I'm looking at a motorcycle that uses the same thread size as well as mounting gasket. Height is about the same, the diameter is within .05 inches, but the bike filter calls for 11-14 PSI bypass. The bike uses 10w40. I'm in the SE US, so never see air temps below maybe 20F, and that's rare. From what I've read here & elsewhere it's unlikely I'll ever use the bypass function. I change oil in my bike every 3K miles, it's a commuter so this ends up being like every 3-4 months.

Could I use these filters? Thanks for any positive advice.
 
The bypass valve is there to prevent the filter media and construction crushing, as much as it is there to protect the engine.

I don't see an issue unless the oil pump struggles to even reach 23 psi.
 
New guy, asking because I'm not entirely clear on the bypass function. I did search here & didn't see a clear answer to this question. I had a Subaru that used 20x1.5 thread filters with a bypass rating around 23 PSI, sold the car, still have some filters. I'm looking at a motorcycle that uses the same thread size as well as mounting gasket. Height is about the same, the diameter is within .05 inches, but the bike filter calls for 11-14 PSI bypass. The bike uses 10w40. I'm in the SE US, so never see air temps below maybe 20F, and that's rare. From what I've read here & elsewhere it's unlikely I'll ever use the bypass function. I change oil in my bike every 3K miles, it's a commuter so this ends up being like every 3-4 months.

Could I use these filters? Thanks for any positive advice.
The By-Pass valve is there to provide lubrication in case of a plugged filter!
The motorcycle manufacturer knows that this will work with oil pressure ~ 11-14 PSI.
If the filter needs a higher pressure it may not open as the motor may not provide adequate pressure
and so starve the engine of oil. Only you can decide if it's worth the risk!
 
From what I've read here & elsewhere it's unlikely I'll ever use the bypass function.
It's unlikely for the filter to clog in 3k miles, but it's not impossible. If the filter does clog, there will be a pressure drop of well over 23 psi across the filter, potentially over 30 psi. This will reduce oil pressure quite a lot, possibly enough to spin a bearing.

Subaru engines can get away with using filters with a high bypass setting because their oil pump pressure relief valves only start to open at 85-102 psi, so a 30 psi pressure drop across the filter isn't going to be that significant. Engines that have lower oil pressure require oil filters with lower bypass settings to prevent oil starvation if the filter clogs.
 
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