School me on bypass valves

[thunderfog]

I got caught up on some threads about Fram oil filters and improperly seated bypass valves. Since I have been using Fram, I got concerned.

But after I did some digging, I discovered my ZR2 Colorado with the 2.7T has the bypass valve in the oil filter housing assembly. I then discovered the XG12447 does not have a bypass valve as a result.

Is that the "ideal" engineering, to have the bypass valve on the block, and an "atta boy" for Chevrolet? Or does it not matter at all, assuming the oil filter is made properly?

 

[ZeeOSix]

I got caught up on some threads about Fram oil filters and improperly seated bypass valves. Since I have been using Fram, I got concerned.

It's not actually the bypass valve, it's the metal leaf spring where it "seals" on the metal end cap. The leaf spring stamping can be ruffled and/or warped so it doesn't sit flat well and seal on the end cap. That's where there could be an air gap to allow oil to bypass the filter media. Been a ton of threads about it over the last year or so.

But after I did some digging, I discovered my ZR2 Colorado with the 2.7T has the bypass valve in the oil filter housing assembly. I then discovered the XG12447 does not have a bypass valve as a result.

Is that the "ideal" engineering, to have the bypass valve on the block, and an "atta boy" for Chevrolet? Or does it not matter at all, assuming the oil filter is made properly?

It's a good design to have the filter bypass valve in the filter mount. Only draw back is that it's a fixed setting so you get that setting regardless of what oil filter is installed. Whereas with the bypass valve built into the filter, the filter designer can match the bypass valve setting to the flow performance (the dP vs flow curve of the filter) and holding capacity of the filter itself.

 

[oil pan 4]

I got caught up on some threads about Fram oil filters and improperly seated bypass valves. Since I have been using Fram, I got concerned.

But after I did some digging, I discovered my ZR2 Colorado with the 2.7T has the bypass valve in the oil filter housing assembly. I then discovered the XG12447 does not have a bypass valve as a result.

Is that the "ideal" engineering, to have the bypass valve on the block, and an "atta boy" for Chevrolet? Or does it not matter at all, assuming the oil filter is made properly?

Yeah a lot of gm engines have a bypass in the filter adaptor or in the block.
If you look at hydraulic filters they usually have the bypass in the filter head.
Problem with the bypass in the bottom of the filter, that's where all the dirt collects.
So of it does go into bypass that dirt and metal shavings are going right back into the engine.
With paper filter the larger chunks of dirt and metal shavings will slide down the paper, collecting at the lowest point when the engine is off.
Synthetic media is supposed to hold more stuff on the media.