Is there a definitive chart that shows the correct oil filter bypass relief valve pressure to correspond with the maximum engine oil pressure? Thanks in advance.
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Oil Filter Bypass Valve Pressure Vs Engine Oil PSI
- Thread starter Ron Jeremy
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The oil filter bypass has nothing to do with engine oil psi in that way. What it does is keep the filter element from imploding and causing a no oil pressure condition. Maybe you are thinking of the relief valve built into the engine.
Ron Jeremy
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Yes I get that, but my question is when they spec a oil filter bypass spring rate, is there a formula that is used to determine what that number should be based on the engine's max oil pressure? Example: if an engine has a max oil pressure of 80 psi, should the filter bypass pressure be 16 psi (these numbers are random, BTW). I realize that the relief valve built into the engine is a factor, so that is considered also and perhaps this is a moot question.
If the filter goes into bypass mode or not is dependant on 4 things:
1) The bypass valve setting (PSI)
2) The oil viscosity
3) The oil pump's flow rate & pressure relief setting.
4) The filter media flow resistance factor.
The filter designer should be designing item 1) around the parameters of 2) thru 4).
Note item 3) ... Both the oil pump's volumetric output (GPM) vs. RPM and the pump's pressure relief setting is important. If you raise the pump's pressure relief setting you are also increasing the maximum oil flow volume as more oil will flow through a fixed resistance (ie, filter+engine series circuit) with a higher pressure.
Go read this thread:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1573625&page=all
1) The bypass valve setting (PSI)
2) The oil viscosity
3) The oil pump's flow rate & pressure relief setting.
4) The filter media flow resistance factor.
The filter designer should be designing item 1) around the parameters of 2) thru 4).
Note item 3) ... Both the oil pump's volumetric output (GPM) vs. RPM and the pump's pressure relief setting is important. If you raise the pump's pressure relief setting you are also increasing the maximum oil flow volume as more oil will flow through a fixed resistance (ie, filter+engine series circuit) with a higher pressure.
Go read this thread:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1573625&page=all
Originally Posted By: Ron Jeremy
I realize that the relief valve built into the engine is a factor, so that is considered also and perhaps this is a moot question.
That's an interesting point, as the vehicles (ie, GMs) with the filter bypass valve built into the filter mount are fixed, unlike with filters where a different brand filter might have a higher or lower bypass setting.
In that case, one would want to try and use a good flowing filter because if you used a more restrictive filter it would have less margin before the bypass valve could open.
I realize that the relief valve built into the engine is a factor, so that is considered also and perhaps this is a moot question.
That's an interesting point, as the vehicles (ie, GMs) with the filter bypass valve built into the filter mount are fixed, unlike with filters where a different brand filter might have a higher or lower bypass setting.
In that case, one would want to try and use a good flowing filter because if you used a more restrictive filter it would have less margin before the bypass valve could open.
The pressure of the filter bypass is the difference before the element and after the element. It has nothing to do with the engine oil pressure.
Originally Posted By: Steve S
The pressure of the filter bypass is the difference before the element and after the element. It has nothing to do with the engine oil pressure.
I does, but in an indirect way. As I mentioned above, IF you increase the oil pressure (by increasing the pump's relief setting) you are also increasing the oil flow rate. Basic fluids 101 say as you increase the pressure you increase the flow rate if the flow resistor and fluid's viscosity is constant.
The filter's PSID will increase with increased oil flow volume ... and that in turn DOES affect the filter's bypass valve opening. If you modified your pump's relief setting to be 120 psi instead of 80, you would probably be putting the filter in bypass at high RPM even with 200+ F oil
The pressure of the filter bypass is the difference before the element and after the element. It has nothing to do with the engine oil pressure.
I does, but in an indirect way. As I mentioned above, IF you increase the oil pressure (by increasing the pump's relief setting) you are also increasing the oil flow rate. Basic fluids 101 say as you increase the pressure you increase the flow rate if the flow resistor and fluid's viscosity is constant.
The filter's PSID will increase with increased oil flow volume ... and that in turn DOES affect the filter's bypass valve opening. If you modified your pump's relief setting to be 120 psi instead of 80, you would probably be putting the filter in bypass at high RPM even with 200+ F oil
When I saw there was a big Motorcraft "S" filter (310?) that fit the VW/Audis but had a lower bypass, it got me thinking what would be the effect of running it. How I see it is that the lower BP could be beneficial in a high-rpm situation, like track use. Instead of filtering 100% ofthe oil every pass, which is totally unnecessary, the BP could pop open and pass a large percent of the oil flow, while filtering on and off at other times.
I know I'm not qualified to make the call, but I know people have used this type of set-up by accident, without any consequence.
I know I'm not qualified to make the call, but I know people have used this type of set-up by accident, without any consequence.
Originally Posted By: Audi Junkie
When I saw there was a big Motorcraft "S" filter (310?) that fit the VW/Audis but had a lower bypass, it got me thinking what would be the effect of running it. How I see it is that the lower BP could be beneficial in a high-rpm situation, like track use. Instead of filtering 100% ofthe oil every pass, which is totally unnecessary, the BP could pop open and pass a large percent of the oil flow, while filtering on and off at other times.
I know I'm not qualified to make the call, but I know people have used this type of set-up by accident, without any consequence.
It would also mean potentially sending a big load of crud off the dirty side of the filter on into the engine.
I thought there were some Subaru turbo engine issues with debris clogging up some kind of orifice downstream of the filter and thereby choking some needed oil flow to the turbo or something else critical. Could be caused by the bypass valve opening and sending crud into the engine.
Instead, use a filter with the higher specified (by Subaru) bypass setting ... that would ensure all the oil is getting filtered, even at high RPM use like at the track.
When I saw there was a big Motorcraft "S" filter (310?) that fit the VW/Audis but had a lower bypass, it got me thinking what would be the effect of running it. How I see it is that the lower BP could be beneficial in a high-rpm situation, like track use. Instead of filtering 100% ofthe oil every pass, which is totally unnecessary, the BP could pop open and pass a large percent of the oil flow, while filtering on and off at other times.
I know I'm not qualified to make the call, but I know people have used this type of set-up by accident, without any consequence.
It would also mean potentially sending a big load of crud off the dirty side of the filter on into the engine.
I thought there were some Subaru turbo engine issues with debris clogging up some kind of orifice downstream of the filter and thereby choking some needed oil flow to the turbo or something else critical. Could be caused by the bypass valve opening and sending crud into the engine.
Instead, use a filter with the higher specified (by Subaru) bypass setting ... that would ensure all the oil is getting filtered, even at high RPM use like at the track.
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Originally Posted By: Audi Junkie
When I saw there was a big Motorcraft "S" filter (310?) that fit the VW/Audis but had a lower bypass, it got me thinking what would be the effect of running it. How I see it is that the lower BP could be beneficial in a high-rpm situation, like track use. Instead of filtering 100% ofthe oil every pass, which is totally unnecessary, the BP could pop open and pass a large percent of the oil flow, while filtering on and off at other times.
I know I'm not qualified to make the call, but I know people have used this type of set-up by accident, without any consequence.
While some cling to this high volume/high performance scenario, this is nothing compared to the VAST number of potential instances of the same scenario occurring at cold start. You can't possibly exist in a race/track scenario with an engine unless you trailer it to the track and never drive it otherwise. The Euro's do this due to the high visc oils and the higher pressure limits on their pumps. Some of the larger sump'd engines take forever to come off of relief due to the high temp requirements of the engine in terms of visc. More relief (deeper/longer)? More elevated PSID (higher/longer).
For a 4-5 quart Audi/VW with an exchanger as a daily driver and not driven like you never got enough sex in your youth?
How long does your gauge hang pegged or exceeding the limit? Once it's off the top, there's not a whole lot to create a bypass scenario.
When I saw there was a big Motorcraft "S" filter (310?) that fit the VW/Audis but had a lower bypass, it got me thinking what would be the effect of running it. How I see it is that the lower BP could be beneficial in a high-rpm situation, like track use. Instead of filtering 100% ofthe oil every pass, which is totally unnecessary, the BP could pop open and pass a large percent of the oil flow, while filtering on and off at other times.
I know I'm not qualified to make the call, but I know people have used this type of set-up by accident, without any consequence.
While some cling to this high volume/high performance scenario, this is nothing compared to the VAST number of potential instances of the same scenario occurring at cold start. You can't possibly exist in a race/track scenario with an engine unless you trailer it to the track and never drive it otherwise. The Euro's do this due to the high visc oils and the higher pressure limits on their pumps. Some of the larger sump'd engines take forever to come off of relief due to the high temp requirements of the engine in terms of visc. More relief (deeper/longer)? More elevated PSID (higher/longer).
For a 4-5 quart Audi/VW with an exchanger as a daily driver and not driven like you never got enough sex in your youth?
How long does your gauge hang pegged or exceeding the limit? Once it's off the top, there's not a whole lot to create a bypass scenario.
Question the on Ford filters. Wix numbers 51315 and 51516. I believe that the only real difference between these filters the bypass setting of 16 psi and 8-11 psi. What does this mean to an engine if you interchange the two? I've seen that many times a shop will stock only a 51516 for use on the fords, even if some of them call for the 51315 with the 16psi bypass. Will you end up with problems by using the lower bypass?
Originally Posted By: Jdblya
Question the on Ford filters. Wix numbers 51315 and 51516. I believe that the only real difference between these filters the bypass setting of 16 psi and 8-11 psi. What does this mean to an engine if you interchange the two? I've seen that many times a shop will stock only a 51516 for use on the fords, even if some of them call for the 51315 with the 16psi bypass. Will you end up with problems by using the lower bypass?
I all depends on why the specific bypass setting was picked by the designers. If both filters flowed the same, then I'd want the filter with the higher bypass setting knowing that it was probably set higher because the designer was probably thinking extended OCI use. Plus, it would endure it would not go into bypass mode as easily as on with a lower setting.
If the bypass setting was designed to be higher on the fact that the filter was more restrictive (because it filtered better), then it would cause a slight loss of oil volume any time the oil pump was in pressure relief mode. A few PSI loss on the top end might or might not be an issue ... but it's usually a trade-off any time a higher efficiency filter is used.
Question the on Ford filters. Wix numbers 51315 and 51516. I believe that the only real difference between these filters the bypass setting of 16 psi and 8-11 psi. What does this mean to an engine if you interchange the two? I've seen that many times a shop will stock only a 51516 for use on the fords, even if some of them call for the 51315 with the 16psi bypass. Will you end up with problems by using the lower bypass?
I all depends on why the specific bypass setting was picked by the designers. If both filters flowed the same, then I'd want the filter with the higher bypass setting knowing that it was probably set higher because the designer was probably thinking extended OCI use. Plus, it would endure it would not go into bypass mode as easily as on with a lower setting.
If the bypass setting was designed to be higher on the fact that the filter was more restrictive (because it filtered better), then it would cause a slight loss of oil volume any time the oil pump was in pressure relief mode. A few PSI loss on the top end might or might not be an issue ... but it's usually a trade-off any time a higher efficiency filter is used.
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The 51315 appears to be exclusively limited to these applications ..which sorta look like the same thing
Make Model Engine
FORD CONTOUR L4 2.0L 1989cc
FORD ESCORT/ESCORT EXP L4 2.0L 121 CID
FORD FOCUS L4 2.0L 121 CID
FORD ZX-2 L4 2.0L 121 CID
FORD LIGHT TRUCKS ESCAPE L4 2.0L 122 CID
MAZDA TRIBUTE L4 2.0L 1991cc
MERCURY COUGAR L4 2.0L 1989cc
MERCURY MYSTIQUE L4 2.0L 1989cc
the 51516 fits these and a whole lot more. It also lists 1 2.0 Focus.
CHRYSLER PT CRUISER L4 2.4L 148 CID
CHRYSLER PT CRUISER L4 2.4L 148 CID Turbo
CHRYSLER PT CRUISER CONVERTIBLE L4 2.4L 148 CID
DODGE NEON L4 2.4L 2429cc
DODGE NEON (SRT-4) L4 2.4L 2429cc
DODGE NITRO V6 3.7L 225 CID
DODGE LIGHT TRUCKS DAKOTA V6 3.7L 226 CID
DODGE LIGHT TRUCKS DURANGO V6 3.7L 226 CID
DODGE LIGHT TRUCKS PICKUP RAM SERIES - ALL L6 3.7L 225 CID
EXCEL+Turf Machines 400 w / Ford VSG411 Engine
EXCEL+Turf Machines 440 w / Ford VSG411 Engine
FORD EDGE V6 3.5L 213 CID
FORD ESCORT/ESCORT EXP L4 1.6L 98 CID
FORD ESCORT/ESCORT EXP L4 1.9L 116 CID
FORD ESCORT/ESCORT EXP L4 2.0L 121 CID
FORD EXP L4 1.6L 98 CID
FORD FOCUS L4 2.0L 121 CID
FORD MUSTANG V6 3.8L 232 CID
FORD MUSTANG V6 3.9L 238 CID
FORD PROBE V6 3.0L 183 CID
FORD TAURUS V6 3.0L 183 CID
FORD TAURUS V6 3.2L 195 CID
FORD TAURUS V6 3.5L 213 CID
FORD TAURUS V6 3.8L 232 CID
FORD TAURUS V8 3.4L 207 CID
FORD TAURUS X V6 3.5L 213 CID
FORD TEMPO V6 3.0L 183 CID
FORD THUNDERBIRD V6 3.8L 232 CID
FORD LIGHT TRUCKS AEROSTAR V6 3.0L 183 CID
FORD LIGHT TRUCKS FLEX V6 3.5L 213 CID
FORD LIGHT TRUCKS FREESTAR V6 3.9L 241 CID
FORD LIGHT TRUCKS FREESTAR V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F-SERIES (ALL) V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F150 ALL V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F150 ALL V8 4.6L 281 CID
FORD LIGHT TRUCKS PICKUP F150 HERITAGE V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F150 SUPERCREW V8 4.6L 281 CID
FORD LIGHT TRUCKS RANGER L4 2.3L 140 CID
FORD LIGHT TRUCKS RANGER L4 2.5L 152 CID
FORD LIGHT TRUCKS RANGER V6 3.0L 183 CID
FORD LIGHT TRUCKS VAN E-SERIES ALL V6 4.2L 256 CID
FORD LIGHT TRUCKS WINDSTAR V6 3.0L 183 CID
FORD LIGHT TRUCKS WINDSTAR V6 3.8L 232 CID
FORD TRUCKS+Also Refer To Light Truck Section E150 w / Ford V6 256 (4.2L) Gas Engine
FORD TRUCKS+Also Refer To Light Truck Section E250 w / Ford V6 256 (4.2L) Gas Engine
Make Model Engine
FORD CONTOUR L4 2.0L 1989cc
FORD ESCORT/ESCORT EXP L4 2.0L 121 CID
FORD FOCUS L4 2.0L 121 CID
FORD ZX-2 L4 2.0L 121 CID
FORD LIGHT TRUCKS ESCAPE L4 2.0L 122 CID
MAZDA TRIBUTE L4 2.0L 1991cc
MERCURY COUGAR L4 2.0L 1989cc
MERCURY MYSTIQUE L4 2.0L 1989cc
the 51516 fits these and a whole lot more. It also lists 1 2.0 Focus.
CHRYSLER PT CRUISER L4 2.4L 148 CID
CHRYSLER PT CRUISER L4 2.4L 148 CID Turbo
CHRYSLER PT CRUISER CONVERTIBLE L4 2.4L 148 CID
DODGE NEON L4 2.4L 2429cc
DODGE NEON (SRT-4) L4 2.4L 2429cc
DODGE NITRO V6 3.7L 225 CID
DODGE LIGHT TRUCKS DAKOTA V6 3.7L 226 CID
DODGE LIGHT TRUCKS DURANGO V6 3.7L 226 CID
DODGE LIGHT TRUCKS PICKUP RAM SERIES - ALL L6 3.7L 225 CID
EXCEL+Turf Machines 400 w / Ford VSG411 Engine
EXCEL+Turf Machines 440 w / Ford VSG411 Engine
FORD EDGE V6 3.5L 213 CID
FORD ESCORT/ESCORT EXP L4 1.6L 98 CID
FORD ESCORT/ESCORT EXP L4 1.9L 116 CID
FORD ESCORT/ESCORT EXP L4 2.0L 121 CID
FORD EXP L4 1.6L 98 CID
FORD FOCUS L4 2.0L 121 CID
FORD MUSTANG V6 3.8L 232 CID
FORD MUSTANG V6 3.9L 238 CID
FORD PROBE V6 3.0L 183 CID
FORD TAURUS V6 3.0L 183 CID
FORD TAURUS V6 3.2L 195 CID
FORD TAURUS V6 3.5L 213 CID
FORD TAURUS V6 3.8L 232 CID
FORD TAURUS V8 3.4L 207 CID
FORD TAURUS X V6 3.5L 213 CID
FORD TEMPO V6 3.0L 183 CID
FORD THUNDERBIRD V6 3.8L 232 CID
FORD LIGHT TRUCKS AEROSTAR V6 3.0L 183 CID
FORD LIGHT TRUCKS FLEX V6 3.5L 213 CID
FORD LIGHT TRUCKS FREESTAR V6 3.9L 241 CID
FORD LIGHT TRUCKS FREESTAR V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F-SERIES (ALL) V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F150 ALL V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F150 ALL V8 4.6L 281 CID
FORD LIGHT TRUCKS PICKUP F150 HERITAGE V6 4.2L 256 CID
FORD LIGHT TRUCKS PICKUP F150 SUPERCREW V8 4.6L 281 CID
FORD LIGHT TRUCKS RANGER L4 2.3L 140 CID
FORD LIGHT TRUCKS RANGER L4 2.5L 152 CID
FORD LIGHT TRUCKS RANGER V6 3.0L 183 CID
FORD LIGHT TRUCKS VAN E-SERIES ALL V6 4.2L 256 CID
FORD LIGHT TRUCKS WINDSTAR V6 3.0L 183 CID
FORD LIGHT TRUCKS WINDSTAR V6 3.8L 232 CID
FORD TRUCKS+Also Refer To Light Truck Section E150 w / Ford V6 256 (4.2L) Gas Engine
FORD TRUCKS+Also Refer To Light Truck Section E250 w / Ford V6 256 (4.2L) Gas Engine
Yeah, the 2.0 Ztech Engines seem to have the 51315
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