I ran an oberg filter that had the bypass plugged, it was a 60 micro screen. It was on a 451, anytime went the engine went above 6600 the pressure dropped from 75 to 60. I am sure it wouldn't have the pressure drop if the bypass wasn't plugged, but if it's bypassing oil then it now really a filter anymore. In fairness, that engine had some pretty loose clearances, so oil demand was a little high.


Joe