good question, on my 86 project, I'm running a remote filter, where are you guys measuring your oil pressure? at the back of the block, or at the filter itself? my filter has ports on both sides for in and out, so at the moment I'm measuring just past the filter, I would assume if the filter should start to clog, etc, this would give me the earliest warning? if I measured at the block, the pressure would still stay high, even if there was restriction? if I can ever get back on my feet, I wanted to run the chariot gauge data logging unit, so I installed a VDO sender on the inlet side of the filter.

 

Pressure measurement should be downstream of the filter, in other words the "OUT" side of the filter

 

Wrong, oil pressure as the car sees it must be measured at the mains, before the filter. Many vehicles, (Like the Honda VTEC oil pressure switch) will measure at separate points.

Any measurement after the filter will result in a lower pressure due to filter resistance. Most oil senders are located right off the pump or the main bearing gallery. This is a non-issues if you change your oil and filter with good parts.

 

Oil sending units are down stream of the filter. If the filter becomes clogged and the bypass valve malfunctions you'll still see "good" pressure that is not reaching the engine.

 

I had to think about that, in passage for the oil filter adapter, it's inline with the pump, and the relief valve, which doesnt make any sense to me, as mentioned a bad filter with a bad bypass would starve the engine of oil yet show good pressure at the gauge, so it's going right after the filter, a clean filter shouldn't show much of a psi drop anyway, and if it does something is wrong. I screwed in the VDO sender which eventually (hopefully) will link to the chariot gauge, in the inlet side of the filter, and the line for the gauge on the outlet side, that will actually give me differential pressure, which is a useful bit of information

 

The bypass is inside the filter. It's purpose is to allow oil to pass if the filter becomes clogged.

The other benefit of a downstream measurement that I didn't mention is a clean sending unit/sensor.

 

I meant to say the pressure relief valve, these have an oil pressure base that bolts to the engine with the pressure relief valve built into it