It will go into bypass every time there is an approx 20 psi difference in pressure between the dirty side and the clean side of the element.
Oil Filter Comparison......
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Originally Posted By: Steve S
It will go into bypass every time there is an approx 20 psi difference in pressure between the dirty side and the clean side of the element.
Yep, but the point was to illustrate the kind of oil pressures/volumes the Modulars are dishing out. It's my bet that the bypass is used quite often during cold starts, as I've witnessed 90+ psi via mechanical OP gauge in 80 degree weather with 5W-20 during a cold start.
It will go into bypass every time there is an approx 20 psi difference in pressure between the dirty side and the clean side of the element.
Yep, but the point was to illustrate the kind of oil pressures/volumes the Modulars are dishing out. It's my bet that the bypass is used quite often during cold starts, as I've witnessed 90+ psi via mechanical OP gauge in 80 degree weather with 5W-20 during a cold start.
Originally Posted By: Ben99GT
With the filter bypass setting at ~20 psi, and the Modulars oil pressure spec at 20-45 psi @ 1500 (HOT) indicating that these filters go into bypass quite often, I will not use a filter with a dome end bypass.
Engine oil pressure at a certain engine RPM gives zero indication if the filter will go into bypass mode or not. It has everything to do with how restrictive the filter is, the oil viscosity and how much oil volume the engine puts through the filter.
With the filter bypass setting at ~20 psi, and the Modulars oil pressure spec at 20-45 psi @ 1500 (HOT) indicating that these filters go into bypass quite often, I will not use a filter with a dome end bypass.
Engine oil pressure at a certain engine RPM gives zero indication if the filter will go into bypass mode or not. It has everything to do with how restrictive the filter is, the oil viscosity and how much oil volume the engine puts through the filter.
Originally Posted By: Ben99GT
Yep, but the point was to illustrate the kind of oil pressures/volumes the Modulars are dishing out. It's my bet that the bypass is used quite often during cold starts, as I've witnessed 90+ psi via mechanical OP gauge in 80 degree weather with 5W-20 during a cold start.
When the oil is cold, there is also a much lower oil flow volume going through the filter/engine circuit due to the pump going into pressure relief. So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
Of course, if you rev the engine like a mad man with cold oil all bets are off because the oil pump's relief valve may not be able to keep up and regulate to the max pump output pressure perfectly under that condition.
Yep, but the point was to illustrate the kind of oil pressures/volumes the Modulars are dishing out. It's my bet that the bypass is used quite often during cold starts, as I've witnessed 90+ psi via mechanical OP gauge in 80 degree weather with 5W-20 during a cold start.
When the oil is cold, there is also a much lower oil flow volume going through the filter/engine circuit due to the pump going into pressure relief. So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
Of course, if you rev the engine like a mad man with cold oil all bets are off because the oil pump's relief valve may not be able to keep up and regulate to the max pump output pressure perfectly under that condition.
Originally Posted By: ZeeOSix
So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
A 60-1700 cSt fluid flowing through the filter media as freely as a 8.5-11 cSt fluid? This is using Pennzoil Ultra 5W-30 and a temperature range of 0-100° F versus ~operating viscosity just as an example.
IMO, if the Modulars didn't go into bypass fairly often, Ford wouldn't be specifying the thread end bypass.
So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
A 60-1700 cSt fluid flowing through the filter media as freely as a 8.5-11 cSt fluid? This is using Pennzoil Ultra 5W-30 and a temperature range of 0-100° F versus ~operating viscosity just as an example.
IMO, if the Modulars didn't go into bypass fairly often, Ford wouldn't be specifying the thread end bypass.
Originally Posted By: Ben99GT
Originally Posted By: ZeeOSix
So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
A 60-1700 cSt fluid flowing through the filter media as freely as a 8.5-11 cSt fluid? This is using Pennzoil Ultra 5W-30 and a temperature range of 0-100° F versus ~operating viscosity just as an example.
IMO, if the Modulars didn't go into bypass fairly often, Ford wouldn't be specifying the thread end bypass.
You're not grasping the concept. When the oil is cold and thick, the oil pump goes into pressure relief very quickly ... and the volume of oil flow going through the filter/engine is way less with cold oil vs. hot oil when the pump is in pressure relief. The volumetric flow rate is a key factor is PSID in the filter. So if the flow is much less, then the PSID is reduced due to reduced flow, but increased due to higher viscosity ... and they then cancel each other out to some degree.
So, "theoretically" if the oil pump can only put out 80 psi regardless of how thick the oil is, then the pressure drop ratio between the engine circuit and the filter should remain the same regardless if the pump is putting out 80 psi with cold oil or hot oil. If the pressure drop ratio is 15:1 (meaning the engine is 15 times more flow resistant than the filter), then with the pump at 80 psi output, the PSID across the filter will be 5 psi (assuming the filter is clean and flows well), and the PSID across the engine will be 75 psi (which is what the oil pressure gauge should show at max pump pressure). If the pump's pressure relief valve is designed correctly, it should keep the max oil supply pressure at 80 psi regardless of the oil's temperature/viscosity.
The key here to grasp this whole concept is that the oil pump's pressure relief valve only allows some set maximum oil pressure on the system regardless of the oil's temperature/viscosity. The maximum volumetric flow rate through the system is controlled by the maximum pump output pressure, and that maximum flow rate will be a function of the oil viscosity. PSID across the filter is dependent on flow and viscosity.
I know this is hard to grasp initially, but if you ponder it for awhile it may snap clear at some point.
The reason Ford uses a base end bypass valve is so when the filter goes into bypass mode it doesn't wash contaminates from the media into the engine. If an oil filter is clogged up pretty good, it can go into bypass mode way before the oil pump ever gets close to max pressure relief point ... regardless if the oil is hot or cold, or if the bypass valve is on the base or in the dome.
Originally Posted By: ZeeOSix
So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
A 60-1700 cSt fluid flowing through the filter media as freely as a 8.5-11 cSt fluid? This is using Pennzoil Ultra 5W-30 and a temperature range of 0-100° F versus ~operating viscosity just as an example.
IMO, if the Modulars didn't go into bypass fairly often, Ford wouldn't be specifying the thread end bypass.
You're not grasping the concept. When the oil is cold and thick, the oil pump goes into pressure relief very quickly ... and the volume of oil flow going through the filter/engine is way less with cold oil vs. hot oil when the pump is in pressure relief. The volumetric flow rate is a key factor is PSID in the filter. So if the flow is much less, then the PSID is reduced due to reduced flow, but increased due to higher viscosity ... and they then cancel each other out to some degree.
So, "theoretically" if the oil pump can only put out 80 psi regardless of how thick the oil is, then the pressure drop ratio between the engine circuit and the filter should remain the same regardless if the pump is putting out 80 psi with cold oil or hot oil. If the pressure drop ratio is 15:1 (meaning the engine is 15 times more flow resistant than the filter), then with the pump at 80 psi output, the PSID across the filter will be 5 psi (assuming the filter is clean and flows well), and the PSID across the engine will be 75 psi (which is what the oil pressure gauge should show at max pump pressure). If the pump's pressure relief valve is designed correctly, it should keep the max oil supply pressure at 80 psi regardless of the oil's temperature/viscosity.
The key here to grasp this whole concept is that the oil pump's pressure relief valve only allows some set maximum oil pressure on the system regardless of the oil's temperature/viscosity. The maximum volumetric flow rate through the system is controlled by the maximum pump output pressure, and that maximum flow rate will be a function of the oil viscosity. PSID across the filter is dependent on flow and viscosity.
I know this is hard to grasp initially, but if you ponder it for awhile it may snap clear at some point.
The reason Ford uses a base end bypass valve is so when the filter goes into bypass mode it doesn't wash contaminates from the media into the engine. If an oil filter is clogged up pretty good, it can go into bypass mode way before the oil pump ever gets close to max pressure relief point ... regardless if the oil is hot or cold, or if the bypass valve is on the base or in the dome.
Originally Posted By: ZeeOSix
Originally Posted By: Ben99GT
Originally Posted By: ZeeOSix
So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
A 60-1700 cSt fluid flowing through the filter media as freely as a 8.5-11 cSt fluid? This is using Pennzoil Ultra 5W-30 and a temperature range of 0-100° F versus ~operating viscosity just as an example.
IMO, if the Modulars didn't go into bypass fairly often, Ford wouldn't be specifying the thread end bypass.
You're not grasping the concept. When the oil is cold and thick, the oil pump goes into pressure relief very quickly ... and the volume of oil flow going through the filter/engine is way less with cold oil vs. hot oil when the pump is in pressure relief. The volumetric flow rate is a key factor is PSID in the filter. So if the flow is much less, then the PSID is reduced due to reduced flow, but increased due to higher viscosity ... and they then cancel each other out to some degree.
I understand the basic concept just fine, but without hard numbers it's all guesswork. With cold thick oil, is the filter the major restriction?
IME, if Ford goes out of their way to spec the thread end bypass valve, and given that I know the kinds of volumes and pressure the Modulars see (higher than most) making the likelihood of a Modular filter seeing bypass greater than say...an LSx, I'll err to the side of caution and stick with filters with the Ford preferred bypass valve location.
Originally Posted By: Ben99GT
Originally Posted By: ZeeOSix
So the PSID in the filter may well be close to the same with cold oil as hot oil. In other words, the PSID ratio between engine an filter will remain the same with any temperature of oil because of the fixed flow resistance factors of each.
A 60-1700 cSt fluid flowing through the filter media as freely as a 8.5-11 cSt fluid? This is using Pennzoil Ultra 5W-30 and a temperature range of 0-100° F versus ~operating viscosity just as an example.
IMO, if the Modulars didn't go into bypass fairly often, Ford wouldn't be specifying the thread end bypass.
You're not grasping the concept. When the oil is cold and thick, the oil pump goes into pressure relief very quickly ... and the volume of oil flow going through the filter/engine is way less with cold oil vs. hot oil when the pump is in pressure relief. The volumetric flow rate is a key factor is PSID in the filter. So if the flow is much less, then the PSID is reduced due to reduced flow, but increased due to higher viscosity ... and they then cancel each other out to some degree.
I understand the basic concept just fine, but without hard numbers it's all guesswork. With cold thick oil, is the filter the major restriction?
IME, if Ford goes out of their way to spec the thread end bypass valve, and given that I know the kinds of volumes and pressure the Modulars see (higher than most) making the likelihood of a Modular filter seeing bypass greater than say...an LSx, I'll err to the side of caution and stick with filters with the Ford preferred bypass valve location.
Hmm, this has got me thinking...
I need a real 101 in terminology here, like PSID, oil pump ratings/capabilities for how much it flows hot/cold vs. filter flow rate etc.
How would the above discussion translate to my applications? A high rev stick shift 5-speed and a 4-speed automatic, one sees more time near the red than the other though I don't race them along much. I've been using Wix/NG for my two cars lately, and I believe Wix/NG filters tend to have dome-end bypass valves, right? How can I tell looking down into a new filter if it has a dome-end bypass valve or one near the base/mounting side?
Is this a bad thing for any car or just ones that could trip bypass mode? Is there any way to find out if an engine like Ben99GT has time when the oil is passing by the FF filter, unfiltered? Wouldn't the oil light come on if the oil filter has to go into bypass(unless the computer already accounts for knowing this happens on his engine???) or would there be a way to check with a scan gauge of some kind?
Caution: I'm new to the game, so forgive me if I'm not up to speed. Trying to learn here.
I need a real 101 in terminology here, like PSID, oil pump ratings/capabilities for how much it flows hot/cold vs. filter flow rate etc.
How would the above discussion translate to my applications? A high rev stick shift 5-speed and a 4-speed automatic, one sees more time near the red than the other though I don't race them along much. I've been using Wix/NG for my two cars lately, and I believe Wix/NG filters tend to have dome-end bypass valves, right? How can I tell looking down into a new filter if it has a dome-end bypass valve or one near the base/mounting side?
Is this a bad thing for any car or just ones that could trip bypass mode? Is there any way to find out if an engine like Ben99GT has time when the oil is passing by the FF filter, unfiltered? Wouldn't the oil light come on if the oil filter has to go into bypass(unless the computer already accounts for knowing this happens on his engine???) or would there be a way to check with a scan gauge of some kind?
Caution: I'm new to the game, so forgive me if I'm not up to speed. Trying to learn here.
Originally Posted By: Ben99GT
I understand the basic concept just fine, but without hard numbers it's all guesswork. With cold thick oil, is the filter the major restriction?
No ... the engine is always more restrictive than the filter regardless of the oil's viscosity. Think of them as fixed flow restrictions, which they basically are for practical purposes of this discussion.
The engine is typically 15 times more restrictive than the filter. That is the whole key to my comments above ... the engine to filter restriction ratio must remain virtually constant regardless of the oil's viscosity.
So if the oil pump still regulates the max oil pressure correctly as designed, even with very thick oil, then the PSID ratio across the filter and engine will basically remain the same. The flow rate is just much less with thicker oil to achieve the max pump pressure which is controlled by it's pressure relief valve.
The flow going through the filter/engine circuit is MUCH higher with hot oil at pump relief pressure than with cold oil at pump relief pressure. A very good reason to keep RPM low until the oil warms up if you really want good flow to all the engine components. The filter's bypass valve should theoretically not open if the pump can control the max pressure to it's valve setting.
But, if the pump's pressure relief valve can not bypass/shunt the excess thick oil, then the outlet pressure will rise above the pump's design pressure relief setpoint and cause higher filter PSID and most likely a filter bypass event.
I understand the basic concept just fine, but without hard numbers it's all guesswork. With cold thick oil, is the filter the major restriction?
No ... the engine is always more restrictive than the filter regardless of the oil's viscosity. Think of them as fixed flow restrictions, which they basically are for practical purposes of this discussion.
The engine is typically 15 times more restrictive than the filter. That is the whole key to my comments above ... the engine to filter restriction ratio must remain virtually constant regardless of the oil's viscosity.
So if the oil pump still regulates the max oil pressure correctly as designed, even with very thick oil, then the PSID ratio across the filter and engine will basically remain the same. The flow rate is just much less with thicker oil to achieve the max pump pressure which is controlled by it's pressure relief valve.
The flow going through the filter/engine circuit is MUCH higher with hot oil at pump relief pressure than with cold oil at pump relief pressure. A very good reason to keep RPM low until the oil warms up if you really want good flow to all the engine components. The filter's bypass valve should theoretically not open if the pump can control the max pressure to it's valve setting.
But, if the pump's pressure relief valve can not bypass/shunt the excess thick oil, then the outlet pressure will rise above the pump's design pressure relief setpoint and cause higher filter PSID and most likely a filter bypass event.
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