[rs-vic]

My understanding is the bypass valve in the oil filter opens at a certain differential pressure. Let's use the MANN filter with 30 psi. To me that means when the oil going into the filter has a 30 psi higher pressure than the oil going out, the bypass valve opens. Normally a filter is on the pressure side so there is more pressure on the back side of the filter, but a 911 has the filter on the return to the tank with virtually no pressure on the back side. My question is does anyone know the approximate pressure before the filter? I know we can't go by engine oil pressure as that is a completely separate system. I am assuming the return side is more volume rather than pressure. Considering most filters have a bypass of around 8-14 psi, the 30 psi of the MANN and Mahle makes more sense for use in the return side.

I recently had to rebuild a 911 engine because the rockers were eating the cam lobes. When I drained the oil out of the tank the magnet in the drain plug was full of metal shavings. This got me to thinking about the effectiveness of the filtration on the tank mounted filter.

Currently I am rebuilding a vintage SWB 911 racer. It has the 993 oil console on the engine and a tank up front in the smuggler's box. It only had an Earl's inline screen mesh filter in the return line to the tank. I would like to install a proper filter. I was thinking a Canton would be the way to go as it is a non bypass filter but after reading the comments about it I have decided against it!

I am going to try the 964 oil console with Mahle filter.