All,
Overall this is a question, but I am throwing my logic/understanding in here as well. I am still trying to be sure of myself before I go forward in making my own bypass setup.
Some general facts:
1. There is pressure drop across the filter and other restrictions in the oiling system, even with a positive displacement pump. There is some misguided logic on this BB that I have seen saying that there is none. Positive displacement pumps have a linear relationship between flow and pump RPM. However, pressure at the pump outlet is dictated by the system's restrictions (and the restrictions typically fluctuate with flow rate). However, there is pressure drop on both sides of a filter, as well as across any other obstacles, whether it be a bend, an orifice, etc. Flow rate is the only thing that is constant through the system.
2. In terms of filter performance and safety for the filter media, differential pressure is all that matters. Assuming the outer case was strong enough, the filter media could handle 1,000 psi (or any pressure), assuming the differential pressure was within the correct amount.
3. In a parallel system, the fluid is going to seek the path of least resistance. The pressure required to pump through all of the restrictions combined in parallel is always less than the lowest restriction by itself.
Given all this, I have no question that if I decide to build a single remote system where oil is supplied from the oil pressure sensor and dumped back into the sump or valve cover, I WILL need a properly-sized orifice to restrict flow, because the differential pressure would quite nearly be equal to the absolute pressure read at the pressure sensor. This would be enough to damage the filter, or at least make me severely worried about it. No questions here on what to do...
However for a dual remote system (i.e. one full full, and one bypass filter, connected in parallel), I am seeing conflicting views on the matter. Here's my logic:
1. The filters are in parallel, with connected flow paths before and after each filter. The pressure drop across both of these in this configuration should be slightly lower than the pressure drop across the full flow filter alone. Because the differential pressure is dictated overwhelmingly by the full flow filter, the differential pressure is quite low. This does D.P. not pose a risk to either filter, so I do not see a need for an orifice for the bypass filter.
It seems to me the ONLY risk by not using an orifice is simply that the bypass filter could have very little flow through it, rendering the system marginally better at filtering than the full flow filter on its own.
However, looking at some of Amsoil's dual remote mounts, there is an orifice in the picture, which I can only assume is for the bypass filter. However, I have seen quotes on this BB in a search saying that an engineer at Amsoil says an orifice is not needed on the dual remote systems. Which one is it then?
I feel that my logic is sound, but I am smart enough to second guess myself when "the name" in bypass technology might do it differently.
I welcome input from those that know what they're talking about, but please don't muddy the waters with inaccurate information, I really am trying to make progress in my understanding here.
Thank you!!
Overall this is a question, but I am throwing my logic/understanding in here as well. I am still trying to be sure of myself before I go forward in making my own bypass setup.
Some general facts:
1. There is pressure drop across the filter and other restrictions in the oiling system, even with a positive displacement pump. There is some misguided logic on this BB that I have seen saying that there is none. Positive displacement pumps have a linear relationship between flow and pump RPM. However, pressure at the pump outlet is dictated by the system's restrictions (and the restrictions typically fluctuate with flow rate). However, there is pressure drop on both sides of a filter, as well as across any other obstacles, whether it be a bend, an orifice, etc. Flow rate is the only thing that is constant through the system.
2. In terms of filter performance and safety for the filter media, differential pressure is all that matters. Assuming the outer case was strong enough, the filter media could handle 1,000 psi (or any pressure), assuming the differential pressure was within the correct amount.
3. In a parallel system, the fluid is going to seek the path of least resistance. The pressure required to pump through all of the restrictions combined in parallel is always less than the lowest restriction by itself.
Given all this, I have no question that if I decide to build a single remote system where oil is supplied from the oil pressure sensor and dumped back into the sump or valve cover, I WILL need a properly-sized orifice to restrict flow, because the differential pressure would quite nearly be equal to the absolute pressure read at the pressure sensor. This would be enough to damage the filter, or at least make me severely worried about it. No questions here on what to do...
However for a dual remote system (i.e. one full full, and one bypass filter, connected in parallel), I am seeing conflicting views on the matter. Here's my logic:
1. The filters are in parallel, with connected flow paths before and after each filter. The pressure drop across both of these in this configuration should be slightly lower than the pressure drop across the full flow filter alone. Because the differential pressure is dictated overwhelmingly by the full flow filter, the differential pressure is quite low. This does D.P. not pose a risk to either filter, so I do not see a need for an orifice for the bypass filter.
It seems to me the ONLY risk by not using an orifice is simply that the bypass filter could have very little flow through it, rendering the system marginally better at filtering than the full flow filter on its own.
However, looking at some of Amsoil's dual remote mounts, there is an orifice in the picture, which I can only assume is for the bypass filter. However, I have seen quotes on this BB in a search saying that an engineer at Amsoil says an orifice is not needed on the dual remote systems. Which one is it then?
I feel that my logic is sound, but I am smart enough to second guess myself when "the name" in bypass technology might do it differently.
I welcome input from those that know what they're talking about, but please don't muddy the waters with inaccurate information, I really am trying to make progress in my understanding here.
Thank you!!