goodeggbob wrote: ↑Sat May 18, 2019 6:08 pm
would i be right in saying,that by using rb sandwich plate for oil pressure,the gauge would read less than true pressure?
There isn't really such a thing as "true pressure". The pressure is highest just as it exits the oil pump. It then drop as it crosses every restriction in the system. So a tiny bit is lost from the coolers and cooler pipes. The pressure into the filter should be close to the highest, and some pressure is lost through the filter. The peak pressure up to this point has all been controlled by the rear relief valve, and some small pressure drop will occur across this valve. More pressure is lost through the ports in the e-shaft, and some pressure is bled away by the rotor jets. Then a lot of pressure is lost across the e-shaft and rotor bearings. When cold the front relief valve will open, causing a drop in oil pressure in the e-shaft. The final pressure drop is the omp feed reservoir (although this is a tiny drop, because it takes a tiny amount of oil. Finally, the oil is squirted back into the sump, and the pressure drop through the sump return feeds drop the pressure to atmospheric. So the oil that is squirted back into the sump is at much lower pressure than the oil exiting the oil pump.
I guess the oil pressure sender can be placed into any of the oil pipe fittings, or into a filter sandwich plate. The filter sandwich plate is the last available location before the oil enters the engine, so it should therefore record marginally the lowest pressure of the available measurement locations, but it's always still higher than what enters the engine. If you can get to the union of the pipe from the front of the engine to the left hand cooler then you should measure the highest pressure. But it makes no odds really. There is an argument that measuring at the sandwich plate is best, because it will tell you if your pipes, coolers, and possibly your filter, are blocked, and what pressure is actually entering the engine.
Note. The RB sandwich plate measures the pressure as the oil enters the filter, so a blocked filter should show up as an increase in pressure, not a decrease.
Apparently being delivered friday 
