Spin on oil filter

[JFP in PA]

Originally Posted by jb92563

Now why would they use a coarser oil filter with some of the oil bypassing the filter element, do you think?

Could it be because the high rates of oil flow in the engine are required to keep everything properly lubed and at the same time cool the engine and should the filter ever become plugged, the bypass will still allow the oil to circulate?!!!

Ahaaaaa!!!!!!!

Spin on finer filter could reduce oil flow because it clogs easier and combined with no oil bypass could lead to engine siezure if the filter gets sufficiently plugged?

I have no idea why they spec a filter with larger pore diameters, but they do. Meanwhile, the spin on is fully capable of outflowing the OEM filter, and the capacity of the oil pump as well, so flow is not an issue.

As for the by-pass, by the time it opens due to the filter clogging, your engine is already toast and full of metal debris. We have seen both spin on and OEM style filter users have rods fail (middle of the rod beam separation, dropped valves, or rod bolt failures) on the track, destroying the engine in the process, and their data loggers showed the car had no interruption of oil pressure when it was shut down (you should see the pressure drop and then come back up if the by-pass was forced to open). The by-pass never came into play.