Dual bypass filter
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When I was referring to the engine's bypass valve, I meant pressure relief valve. Actually the terms are one and the same. Sorry for the confusion.
I don't have my dual bypass system hooked up yet in my car. I had to first dig up an adapter fitting to get an oil pressure gauge hooked up. I want to make sure I have a "before and after" picture of oil pressure at high and low RPM.
Others that have the same car I have state that they have seen oil pressure readings as high as 95 psi at redline, and that the pressure increases linearly with RPM up to that pressure. That tells me that (at least on my car) the pressure relief valve kicks in above 95 psi.
RavenTai: you say that "when I start my truck cold the oil pressure goes strait to 70 even at idle". Are you using straight weight oil? That's different than the experiences I've had.
I don't have my dual bypass system hooked up yet in my car. I had to first dig up an adapter fitting to get an oil pressure gauge hooked up. I want to make sure I have a "before and after" picture of oil pressure at high and low RPM.
Others that have the same car I have state that they have seen oil pressure readings as high as 95 psi at redline, and that the pressure increases linearly with RPM up to that pressure. That tells me that (at least on my car) the pressure relief valve kicks in above 95 psi.
RavenTai: you say that "when I start my truck cold the oil pressure goes strait to 70 even at idle". Are you using straight weight oil? That's different than the experiences I've had.
I'd like to throw in a few thoughts here:
Some oil psi senders are plumbed before the filter.
Bob's testing proved one thing that is clear. The Amsoil Dual remote mount will NOT handle the same throughput volume as the single Fram full flow element used pure and simple.
IMHO, the hoses used are too small.
Now I guess there is one thing to consider. What size was the hose opening draining from the after gauge? If it was larger than the from filter hose, this will cause psi drop. If sized the same, then things are nearly equal.
It would be interesting to see what would happen in a direct plumb setup with the gauges mounted directly at the filter mount's in/out ports.
Personally, I'd have chosen a non bypass equipped element.
A couple of things worth remembering:
A filter bypass is a differential psi valve. If the psi drop exceeds the rating it will open.
Pressure drop as measured in Bob's test is only a serious concern IF the bearing clearances etc. allow a major drop in psi.
What engines have that? That doesn't even make sense. With that setup, you could theoretically have a totally plugged oil filter, pressure relief valve wide open, high oil pressure and absolutely no oil getting to the engine.
Sure, the Fram oil filter can handle more flow because the bypass valve can open up. But the Amsoil full flow filter on the DB setup is much larger than most standard filters, therefore can handle more fully filtered flow.
I've yet to hear from anyone that has claimed to have a problem with the dual bypass setup. Everyone is entitled to their opinion as to how ineffective this setup might be, but at this point they are just opinions.
That is just untrue, Those hoses are big enough to flow more oil than your engine will ever need. All these comments about Bob's backyard test are so messed up. Do you think that is the type of testing that went into the Bypass system?
I am not away of any engine restrictions for the by-pass filter, I'm not aware of any problems associated with the by-pass system.
I have seen the exact same Amsoil Dual Remote System mounted on cars from little 4 cylinder 125hp to 400+hp Diesel engines. All oil analysis have improved over regular filtration. Engines are lasting longer with oil drains 10-100 times that with regular filtration.
So why don't we move to a different subject.
???
There is actually quite a negative discussion of the BMK-13 dual filter mount on pages 5 and 6 of Bob's original oil test. There ARE some very significant concerns and actual measurements on these pages that would cause me not to use such an arrangement on my engine. Others are free to make their own judgements...
IMO, the most relevant and irrefutable information was posted originally on Bob's study (page 6) by nooklvr, an actual user of the Amsoil BMK13. I apologize for the long quote here, but I think it is needed to reduce the number of hypotheses/opinions being posted on this subject. We need some actual numbers/experiences and the following user comes the closest to this:
Steve
There is actually quite a negative discussion of the BMK-13 dual filter mount on pages 5 and 6 of Bob's original oil test. There ARE some very significant concerns and actual measurements on these pages that would cause me not to use such an arrangement on my engine. Others are free to make their own judgements...
IMO, the most relevant and irrefutable information was posted originally on Bob's study (page 6) by nooklvr, an actual user of the Amsoil BMK13. I apologize for the long quote here, but I think it is needed to reduce the number of hypotheses/opinions being posted on this subject. We need some actual numbers/experiences and the following user comes the closest to this:
While the Amsoil bypass filter appears to be doing a good job (just look at the oil analysis results), Nooklvr's conclusion is my conclusion -- there are better ways to connect a bypass filter to an engine, ones that do not have increased bearing/rod noises ("rattle") at startup and ones that have no potential or real issues with reduced oil flows or pressures.
Steve
That's a very good post, Mangusta. There's a lot of good information there, and it was put together in an unbiased, believable format.
I would have expected a lower pressure ceiling at high RPMs as described, but not the valve train noise at startup. It would be interesting to see his installation. If one of the ADBVs did not close adequately and the system was mounted significantly higher than the car's oil filter mount, then he may be getting some siphoning back to the oilpan. I find it hard to believe that the restrictor alone would account for the rattle.
I would have expected a lower pressure ceiling at high RPMs as described, but not the valve train noise at startup. It would be interesting to see his installation. If one of the ADBVs did not close adequately and the system was mounted significantly higher than the car's oil filter mount, then he may be getting some siphoning back to the oilpan. I find it hard to believe that the restrictor alone would account for the rattle.
It has been quite a while since I read Bobs oil filter flow test but I am not quite sure but the filtered return oil returned to the sump with out a restriction after the filter ?[the oil pumped through the bearings etc. is the restriction so you will see as the engine wears the clearences increase and the oil pressure decreases] If so the the filters were not operating as designed.
Interesting quote Steve. It's also interesting that no matter where you stand on this issue you can read the contents and find it supports your opinion.
There was a barely measureable drop in pressure, and a noticable drop at high rpm. According to the flow Flow capacity formula, this is exactly what you would expect to happen when you pump the same fluid through two different pices of hardware with different flow capacities at the same rate of flow, and compare the drop in pressure from one end to the other.
We have no reason to expect the rate of flow in a positive displacement pump driven by a computer controlled engine will change depending on what is connected to the pump. The difference between the stock filter and the DB is not even significant enough to make a measureable difference in gas milage.
In general we know
1) If you reduce the flow capacity of the by-pass and flow the same fluid at the same rate, (gallons per minute,) the pressure will increase on the input side. It's going to take increased pressure to pump at the same rate.
Based on the formula we know this to be true:
1) If you reduce the flow capacity of the by-pass and flow the same fluid at the same rate, the pressure drop from, (input to output) will increase.
2) If you increase the rate of flow through any by-pass filter the pressure drop will increase
3) If you increase the viscosity, (resistance to flow,) the flow capacity of any filter will be reduced and as a result, pressure drop will increase. This is the case when oil is cold and thicker.
The best way to determine if your engine is getting enough oil is to measure the rate of flow. Since flow meters are expensive we use a pressure gage as a meaningful measure. A DB will increase the oil pressue on the input line, and reduce the pressure on the output line, increasing the pressure drop measured between the two, even though the rate of flow is unchanged.
What we need to ask is this, Is the psi of the oil in the oil galleys lower with at DB? Does the psi of the oil in the galleys matter? Does the DB filter increase oil pressure in front of the pump? What is the real loss of oil pumped through the system? Is it a significant amount, and where does it go?
[ December 31, 2003, 09:42 PM: Message edited by: greencrew ]
There was a barely measureable drop in pressure, and a noticable drop at high rpm. According to the flow Flow capacity formula, this is exactly what you would expect to happen when you pump the same fluid through two different pices of hardware with different flow capacities at the same rate of flow, and compare the drop in pressure from one end to the other.
We have no reason to expect the rate of flow in a positive displacement pump driven by a computer controlled engine will change depending on what is connected to the pump. The difference between the stock filter and the DB is not even significant enough to make a measureable difference in gas milage.
In general we know
1) If you reduce the flow capacity of the by-pass and flow the same fluid at the same rate, (gallons per minute,) the pressure will increase on the input side. It's going to take increased pressure to pump at the same rate.
Based on the formula we know this to be true:
1) If you reduce the flow capacity of the by-pass and flow the same fluid at the same rate, the pressure drop from, (input to output) will increase.
2) If you increase the rate of flow through any by-pass filter the pressure drop will increase
3) If you increase the viscosity, (resistance to flow,) the flow capacity of any filter will be reduced and as a result, pressure drop will increase. This is the case when oil is cold and thicker.
The best way to determine if your engine is getting enough oil is to measure the rate of flow. Since flow meters are expensive we use a pressure gage as a meaningful measure. A DB will increase the oil pressue on the input line, and reduce the pressure on the output line, increasing the pressure drop measured between the two, even though the rate of flow is unchanged.
What we need to ask is this, Is the psi of the oil in the oil galleys lower with at DB? Does the psi of the oil in the galleys matter? Does the DB filter increase oil pressure in front of the pump? What is the real loss of oil pumped through the system? Is it a significant amount, and where does it go?
[ December 31, 2003, 09:42 PM: Message edited by: greencrew ]
looks like that is for me, the motor is a 8.1L chevy (496CI big block) based on the old 454 with a longer stroke and installed in a "heavy duty" truck that is rated to haul/tow a large amount, not what you would traditionally call high performance but not a standard engine either.
just because things do not fit your expectations does not make them impossible
but I do agree with some of what you said as I said earlier in the thread
but if the pressure relief valve is open increased resistance to flow will result in reduced flow to the oil galleys.
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Quite true
Naturally I believe my readings
If some of my post sounded redundant to parts of yours ...it is more my inability to integrate others descriptive style ..then it is of me ignoring what you posted.
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Greencrew,
I think we need to put everything on an even playing field. If you're talking flow ...keep everything in flow. If you're talking pressure ...you've got to compare issues based on that alone. The two just don't interchange in this environment easily ..at least in regard to "perception".
Some people here have some incredible oil pressures. Some I find hard to believe in a contempory engine that typically specifies 5w-30 so that it consumes less energy to pump the lubricant through the engine. This is the ONLY reason for the evolution of these lighter weight oils. 70 psi on anything other than a high performance engine is wasting so much energy I find it an "anomaly". I would find 25-45 psi a more credible number (warm -off idle).
Beyond all that ....
Unless you're up against the pressure relief of the oil pump (which we will for the moment say is the MAX oil pressure that the engine EVER achieves (this is not always so - in my case the high volume pump can produce more flow than can be relieved so my 58 psi can be pushed to 60+ on a really cold day right after start up). Hence it doesn't matter (IN REGARD TO FLOW) whether you have a Fram ..a dual bypass ...or an open can ..the flow remains the same. Only the energy (pressure) disapated to pump is is distributed differently overcoming the resistance to the flow. 5 gpm is 5 gpm. To the engine ..it means "I'm seeing 5 gpm of flow @ 30 psi" ..or "I'm seeing 5 gpm of flow @ 45 psi".
So it could be said that any pressure under the oil pump's pressure relief rating gives FULL FLOW and is otherwise indifferent to any intermediate restrictions.
Yes, pressure drop is resistance to flow ..but the way most here perceive it is with the ASSUMPTION of reduced flow. They don't have the natural ability to apply the theory with flow being a constant.
That all being said ....why don't those who don't like the little "biasing" valve just take it out? I adapted my PermaCool (already plumbed) to use the Cummins size Amsoil filters (their threaded adaptors) and the only thing that occurs (and this occurs WITH the restrictor valve installed as well) is that the bypass has a reactive component, or "impedence", to higher viscosities (cold oil) and will naturally route most of the oil throught the full flow until the oil thins after warm up.
The thing works fine without it albeit to a lesser degree of filtration efficiency.
I think we need to put everything on an even playing field. If you're talking flow ...keep everything in flow. If you're talking pressure ...you've got to compare issues based on that alone. The two just don't interchange in this environment easily ..at least in regard to "perception".
Some people here have some incredible oil pressures. Some I find hard to believe in a contempory engine that typically specifies 5w-30 so that it consumes less energy to pump the lubricant through the engine. This is the ONLY reason for the evolution of these lighter weight oils. 70 psi on anything other than a high performance engine is wasting so much energy I find it an "anomaly". I would find 25-45 psi a more credible number (warm -off idle).
Beyond all that ....
Unless you're up against the pressure relief of the oil pump (which we will for the moment say is the MAX oil pressure that the engine EVER achieves (this is not always so - in my case the high volume pump can produce more flow than can be relieved so my 58 psi can be pushed to 60+ on a really cold day right after start up). Hence it doesn't matter (IN REGARD TO FLOW) whether you have a Fram ..a dual bypass ...or an open can ..the flow remains the same. Only the energy (pressure) disapated to pump is is distributed differently overcoming the resistance to the flow. 5 gpm is 5 gpm. To the engine ..it means "I'm seeing 5 gpm of flow @ 30 psi" ..or "I'm seeing 5 gpm of flow @ 45 psi".
So it could be said that any pressure under the oil pump's pressure relief rating gives FULL FLOW and is otherwise indifferent to any intermediate restrictions.
Yes, pressure drop is resistance to flow ..but the way most here perceive it is with the ASSUMPTION of reduced flow. They don't have the natural ability to apply the theory with flow being a constant.
That all being said ....why don't those who don't like the little "biasing" valve just take it out? I adapted my PermaCool (already plumbed) to use the Cummins size Amsoil filters (their threaded adaptors) and the only thing that occurs (and this occurs WITH the restrictor valve installed as well) is that the bypass has a reactive component, or "impedence", to higher viscosities (cold oil) and will naturally route most of the oil throught the full flow until the oil thins after warm up.
The thing works fine without it albeit to a lesser degree of filtration efficiency.
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