Bypass PSI

[Birdman2010]

I joined this forum because I know that there are a LOT of oil gurus here! I cannot seem to find the "Bypass PSI" or the "Max Flow Rate" for the SuperTech product line. I am specifically interested in the specs for the SuperTech ST9688, which replaces the SuperTech ST7317. I also want to find the max flow rate for the Bosch 3323. Any ideas on where I can find these specs?

So far, I have these specs, which I found on company websites:

Wix 51356, 8-11 PSI bypass, 9-11 GPM max flow rate
Mobil 1 M1-110, 13 PSI bypass, 3 GPM max flow rate
Bosch 3323, 11-17 PSI bypass, ?? max flow rate

 

[BrocLuno]

Flow rate will depend on viscosity and that will depend on oil selected and op temp. When oil is cold, flow is very low through the media, so most filters by-pass. Many will open at 12 PSI or so.

That's why I always suggest using the biggest filter that will fit. The extra media surface area means that sometimes even cool/cold oil will filter

It certainly means that the bypass will close sooner as the oil even begins to warm up, it will go through the media

For race motors we often block all bypass's and use hydraulic filters w/o internal bypass's. That way if we blow a timing gear, or loose a cam, at least all the oil goes through a filter and the damage is less to deal with.

But race motors don't usually have to start curbside at 30*F, so that does not apply to daily drivers ...

 

[ZeeOSix]

Originally Posted By: Birdman2010
So far, I have these specs, which I found on company websites:

Wix 51356, 8-11 PSI bypass, 9-11 GPM max flow rate
Mobil 1 M1-110, 13 PSI bypass, 3 GPM max flow rate
Bosch 3323, 11-17 PSI bypass, ?? max flow rate


Those "specs" are pretty much worthless unless there is some kind of delta-p across the filter given at those flow rates, and with what oil viscosity/temperature.

The onlty half way logical meaning they might have is that it's the flow in GPM with hot oil at the point when the bypass valve starts to open up.

Mobil 1 is only 3 GPM max ... must be a mis-print.

 

[ZeeOSix]

On a related topic, if you want to see that the filter bypass valve rarely opens, then read this thread (it's a sticky at top of this forum). Unfortunately, Jim Allen doesn't hang out here anymore, and all the graphs of his testing are no longer hosted and therefore don't show up anymore in is first post.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3197094/Differential_Pressure_Data,_Pu#Post3197094

High rev with thick cold oil is what causes filters to bypass. Once the oil warms up some it's pretty rare for the bypass valve to open unless the filter is really getting clogged up.

 

[slacktide_bitog]

The Bosch 3323 a reboxed PL14610