A dual oil filters
- Thread starter Wnmshoe
- Start date
U.A.V.Nissan
New member
Had one on my first car a 1998 Ford Escort ZX2 with 298k on the dash.
Was able to do extended oil changes from 4,000 to 12,000 by just replacing the oil filters and toping the oil off, I used Amsoil on all the fluids.
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Was able to do extended oil changes from 4,000 to 12,000 by just replacing the oil filters and toping the oil off, I used Amsoil on all the fluids.
Sent from my iPhone using Tapatalk
SoCal Tom
Explorer
They are a waste of money. Filters remove particles, so if your engine is full of dirt you should keep it out of the engine. When oil breaks down it forms acids and other stuff bad for bearings and seals. Synthetic oils can resist the break down longer, and studies show most engines can make 7500 miles between changes on normal oil. The only real benefit of a extra filter is then additional oil capacity. An oil cooler would do a better job of that and will help keep the oil cooler so it would probably take less time to break down.
Tom
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Tom
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comptiger5000
Adventurer
Generally filter capacity isn't the limiting factor on how long oil changes can go. SoCal Tom explained it pretty well. If you want to know how long you can go, the best way is to send an oil sample for analysis to see what it looks like.
drewactual
Adventurer
are we speaking an additional full flow filter or are we talking a by-pass filter?
an additional full flow theoretically extends the life of the filter IF they are in parallel and NOT series. Even if set up in parallel, managing the flow is tricky- but if done correctly has the potential to not only double a full flow filters life, but also to protect against drain-back/anti siphon device failures. There was a time when these were an issue, but not so much anymore.
if we're talking a by-pass system, they are absolutely worth it, depending on the use and expense of the engine. Unlike a full flow which are rated to capture anything above 40um and most above 25um (99.5% efficiency), a 2um by-pass filter captures anything larger than 2um 99.9% of the time, or dang near absolute... they need to be implemented at or near the full flow filter for a feed, and reintroduced at or near the oil fill, valve covers, or tower (which is basically the same spot) where pressures can't be interrupted... the idea is to pull around 10% of the flow from the back up around the full flow filter (and you'll notice the pressure drop because of it being there) and push it through the by-pass filter. Depending on total sump volume, ALL the oil is scrubbed down to 2um every twenty minutes or so run time.
to suggest a by-pass isn't worth it is insane. most engine damage by particulates in the oil happen with debris 5-7um, or a size that passes right through the full flow filter as if it isn't even there... Oil doesn't 'wear out', it becomes contaminated to the point of exhaust- meaning the lubricity is compromised by the ash and other contamination to the point of becoming neutral. Additives DO exhaust, but if the oil could possibly remain clean enough, all that would be needed for the lifetime of an engine would be new filters every so often, and an oil additive/restoration product.
a lot of attention is placed on pressure... pressure is cool.... volume is the important thing, though- figured by pressure readings... go figure... a second full flow filter in series will create pressure- and folks will think all is well, when they've cut the velocity of the volume, which is far from 'well'... introducing a second full flow in properly installed parallel will cut pressure, and will not hamper velocity of volume or the volume one iota- but what is there really to gain? A by-pass introduces two distinct concerns- one being the actual volume of oil being delivered at higher RPM's being cut because the pressure relief introduced by the bypass feed... the next is the addition of lines and connections that could fail, although that is a remote possibility if the system is installed properly. For this reason a by-pass filter head needs to be carefully considered... an orifice of .005 might be fine for one engine, where for another it allows too much volume through at various RPM's, in effect starving items immediately following the pump and full flow filter of cooling and lubricity...
I run a high quality oil in my rig exclusively. I have an amsoil by-pass filter kit installed (90 size), and after inline coolers (not for cooling as much as for using something rigid/hard between the feed and the dump instead of soft lines that may or may not hold up). I use oil analysis every 5k miles, and have been told to run in excess of 20k miles safely, but my OCD will NOT let me go above 15k no matter how hard I try. I was told at 5k miles the sample was analytically duplicate to the virgin sample I sent of the same oil. I was told at 10k that the sample then was only mildly used, and equiv to 'half' the wear of the first 5k sample sent while using that oil and prior to installing the by-pass filter. This speaks to wear metals and ash- it DOES NOT speak to total base number (TBN) of the oil... The TBN is where your detergents and wear additives hang out in any oil analysis, and (this next bit is important) it's depletion is the only reason I've needed (thank you OCD) to change my oil since introducing the by-pass filter.
the oil I use is tinted green, which I assume is a marketing/ID thing the company uses, and right now I'm at around 9k miles, w/ a total sump capacity of around 18qts, and the green color is still plainly evident. I've seen it as high as 210 engine oil temperature (EOT), and I've ran it most often (this fall until now) never exceeding 197EOT...
not only does my engine agree (levi's dyno and ear), but the numbers as produced by the laboratory do as well- a by-pass oil filter is WELL worth it... for my engine, anyway, which costs over $25k to replace, and well over $10k just to get full access to and turn a single bolt... so, yeah.. it's worth it for me.
virgin sample^
after first 8k I think it was^
I think this pic was of the oil I drained at 15k miles, that was far from spent.
looking down the run of the inline coolers to teh by-pass filter head- I had to clear a CCV can and a Coolant Filter, as the by-pass is supposed to be installed in the same spot as the coolant filter. I used the coolers as to make the run as rigid as possible instead of having concerns of cut lines along the way... ^
looking from the filter forward ^
the connection from the engine to the lines ^
I don't have pics of the feed or dump handy, but the feed is off the top of the full flow filter bowl, and the dump is in the cap of the tower- both have -6AN fittings and 1/4" OD steel wound lines.
an additional full flow theoretically extends the life of the filter IF they are in parallel and NOT series. Even if set up in parallel, managing the flow is tricky- but if done correctly has the potential to not only double a full flow filters life, but also to protect against drain-back/anti siphon device failures. There was a time when these were an issue, but not so much anymore.
if we're talking a by-pass system, they are absolutely worth it, depending on the use and expense of the engine. Unlike a full flow which are rated to capture anything above 40um and most above 25um (99.5% efficiency), a 2um by-pass filter captures anything larger than 2um 99.9% of the time, or dang near absolute... they need to be implemented at or near the full flow filter for a feed, and reintroduced at or near the oil fill, valve covers, or tower (which is basically the same spot) where pressures can't be interrupted... the idea is to pull around 10% of the flow from the back up around the full flow filter (and you'll notice the pressure drop because of it being there) and push it through the by-pass filter. Depending on total sump volume, ALL the oil is scrubbed down to 2um every twenty minutes or so run time.
to suggest a by-pass isn't worth it is insane. most engine damage by particulates in the oil happen with debris 5-7um, or a size that passes right through the full flow filter as if it isn't even there... Oil doesn't 'wear out', it becomes contaminated to the point of exhaust- meaning the lubricity is compromised by the ash and other contamination to the point of becoming neutral. Additives DO exhaust, but if the oil could possibly remain clean enough, all that would be needed for the lifetime of an engine would be new filters every so often, and an oil additive/restoration product.
a lot of attention is placed on pressure... pressure is cool.... volume is the important thing, though- figured by pressure readings... go figure... a second full flow filter in series will create pressure- and folks will think all is well, when they've cut the velocity of the volume, which is far from 'well'... introducing a second full flow in properly installed parallel will cut pressure, and will not hamper velocity of volume or the volume one iota- but what is there really to gain? A by-pass introduces two distinct concerns- one being the actual volume of oil being delivered at higher RPM's being cut because the pressure relief introduced by the bypass feed... the next is the addition of lines and connections that could fail, although that is a remote possibility if the system is installed properly. For this reason a by-pass filter head needs to be carefully considered... an orifice of .005 might be fine for one engine, where for another it allows too much volume through at various RPM's, in effect starving items immediately following the pump and full flow filter of cooling and lubricity...
I run a high quality oil in my rig exclusively. I have an amsoil by-pass filter kit installed (90 size), and after inline coolers (not for cooling as much as for using something rigid/hard between the feed and the dump instead of soft lines that may or may not hold up). I use oil analysis every 5k miles, and have been told to run in excess of 20k miles safely, but my OCD will NOT let me go above 15k no matter how hard I try. I was told at 5k miles the sample was analytically duplicate to the virgin sample I sent of the same oil. I was told at 10k that the sample then was only mildly used, and equiv to 'half' the wear of the first 5k sample sent while using that oil and prior to installing the by-pass filter. This speaks to wear metals and ash- it DOES NOT speak to total base number (TBN) of the oil... The TBN is where your detergents and wear additives hang out in any oil analysis, and (this next bit is important) it's depletion is the only reason I've needed (thank you OCD) to change my oil since introducing the by-pass filter.
the oil I use is tinted green, which I assume is a marketing/ID thing the company uses, and right now I'm at around 9k miles, w/ a total sump capacity of around 18qts, and the green color is still plainly evident. I've seen it as high as 210 engine oil temperature (EOT), and I've ran it most often (this fall until now) never exceeding 197EOT...
not only does my engine agree (levi's dyno and ear), but the numbers as produced by the laboratory do as well- a by-pass oil filter is WELL worth it... for my engine, anyway, which costs over $25k to replace, and well over $10k just to get full access to and turn a single bolt... so, yeah.. it's worth it for me.
virgin sample^
after first 8k I think it was^
I think this pic was of the oil I drained at 15k miles, that was far from spent.
looking down the run of the inline coolers to teh by-pass filter head- I had to clear a CCV can and a Coolant Filter, as the by-pass is supposed to be installed in the same spot as the coolant filter. I used the coolers as to make the run as rigid as possible instead of having concerns of cut lines along the way... ^
looking from the filter forward ^
the connection from the engine to the lines ^
I don't have pics of the feed or dump handy, but the feed is off the top of the full flow filter bowl, and the dump is in the cap of the tower- both have -6AN fittings and 1/4" OD steel wound lines.
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comptiger5000
Adventurer
A bypass filter will certainly keep the oil cleaner (and cleaner looking). And it may be able to extend the time between changes on engines that put a good bit of soot into the oil (especially diesels). On the other hand, for a gas engine used on a lot of shorter trips (especially in cold weather), the benefits are less. Filtering out the smaller bits will still reduce wear, but the oil will likely need changing due to TBN depletion before anything else becomes a real concern.
drewactual
Adventurer
agreed... but it should be said the TBN is acceptable far beyond a 3, 5, or even 10k oil change interval... the TBN can live upwards of 40k miles IF the oil isn't contaminated by debris- to include immersion- before that period... even then, if a person wanted to they could simply dump a nutrient into the sump and let it restore the TBN- but only on a debris/contaminant free oil... over the road trucking firms often times run well above a quarter million miles between intervals by using a bypass of suitable size, and nutrient/additive packs every 50k miles or so... given, as you said, these engines aren't just ran in short spurts... that makes a big difference.
comptiger5000
Adventurer
Those engines also have a heck of a lot more than 5 quarts of oil to spread the moisture / fuel / acid contamination through, so they'll take a lot more before it degrades the oil to a concerning point.
IIRC, from the last analysis I did on my ZJ, with it seeing DD use, I was good for around 7500 miles before TBN became a real concern (was down to 2.4 after 6k miles from a starting value of 10.6), so I kept to 6k changes to account for more condensation and such during the winter and some variance in my usage patterns. I should do another analysis at some point, as my driving patterns are a bit different than they used to be, the motor is more modded and my commute is also longer.
IIRC, from the last analysis I did on my ZJ, with it seeing DD use, I was good for around 7500 miles before TBN became a real concern (was down to 2.4 after 6k miles from a starting value of 10.6), so I kept to 6k changes to account for more condensation and such during the winter and some variance in my usage patterns. I should do another analysis at some point, as my driving patterns are a bit different than they used to be, the motor is more modded and my commute is also longer.
rayra
Expedition Leader
Money is better spent on a higher capacity pan / sump. Greater fluid volume, cooler running, longer intervals between servicing, greater sustainability if you develop a leak in the middle of nowhere. All good for an 'expedition' vehicle.
Dual-filter is more suitable for high performance or race engines, where high break-in wear is occurring and you need higher flow rates at screaming RPMs
Dual-filter is more suitable for high performance or race engines, where high break-in wear is occurring and you need higher flow rates at screaming RPMs