Dual bypass filter

10K-PCW-Jr · Dec 16, 2003

Amsoil single bypass takes it's pressure from a HP source and then returns it to the pan/valve cover/hollow bolt etc.
The Amsoil Dual bypass has the FF and the Bypass filter on the same head and uses an adapter on the FF mount to press and return all oil flow to the remote FF/bypass set up.
Good pictures and explanation on the Amsoil site.

rugerman1 · Dec 16, 2003

greencrew · Dec 18, 2003

Though Bob's test was very interesting and educational, it had no oil galleys. I don't think we know for sure that the filter has more resistance than the oil galleys do. I don't think we can reasonably make any conclusions on wether the oil flow reduction resulting from a dual bypass is significant enough to cause concern or even be an issue.

Remember, real people are running these on their $36,000 trucks, so a serious answer is important to those running a dual by-pass or considering one.

The best solid results we have seen so far as I see it is the results from msparks, who ran his oil 20,000 miles and posted excellant results in both a used oil analysis and a particle count. Here on BITOG do we have a better way to measure the results?

Granted, it is hard not to agree that the by-pass filter covers up any wear metals be filtering them out of the system and the sample, but it's also hard not to agree that the sample is the same oil running through those oil galleys.

msparks · Dec 18, 2003

quote:

Originally posted by greencrew:
Granted, it is hard not to agree that the by-pass filter covers up any wear metals be filtering them out of the system and the sample, but it's also hard not to agree that the sample is the same oil running through those oil galleys.

There is no way that any bypass can coverup, filter out, or otherwise change the wear metals in a sample. Wear metals are not measured by counting the particles as they become part of the oil at an atomic level. Wear metals cannot be filtered out.

Hope this helps

greencrew · Dec 18, 2003

quote:

Originally posted by msparks:
There is no way that any bypass can coverup, filter out, or otherwise change the wear metals in a sample. Wear metals are not measured by counting the particles as they become part of the oil at an atomic level. Wear metals cannot be filtered out.

Good point, I had not thought of that. It must filter out some of the big chunks though?

msparks · Dec 18, 2003

quote:

Originally posted by greencrew:
Good point, I had not thought of that. It must filter out some of the big chunks though?

If you have "big" chunks in your oil you have "big" problems. Wear metals should not be in chunks.

Do this for a test. Take a piece of lead. rub it with your finger. This is what is taking place. you will not pull off "chuncks" you will be wearing the lead. I would probably guess that the wear from that is substantially larger than the wear that is going on it your engine since you have a lubricant to stop 99% of that. If you put some oil on your finger and rubbed the lead I would image that you couldn't possibly do it long enought to build up any "wear" metal on your finger.

Does this make sense?

greencrew · Dec 19, 2003

quote:

Originally posted by msparks:
Does this make sense?

It does, but not completely. The advantage of the by-pass is it's ability to filter out particles better than the full flow filter. What particles are filtered out. When I look at this link I see less wear metals for the full flow filter:

http://jeepsunlimited.com/forums/showthread.php?s=&postid=2967909

Is it then that the by-pass filters out silicon and soot resulting in less wear metals? I am convinced that the by-pass will clean up dirty oil, but not quite sure what is being cleaned up.

I do remember with my toilet paper filter I could tell when I was late with my filter change because of the darker color of the oil, and cooler canister. Once I put in a clean filter the oil would lighten in color and the canister was too hot to touch. I never did analyze that oil, but wish I would have.

mangusta1969 · Dec 19, 2003

Greencrew,

Typo in your post?? I think you meant to say "I see less wear particles filtered out for the full flow filters".

In looking at the quantitative data, the best of the full flow filters (the Mobil 1 Filter) reduced the number of suspended metal particles between 18-41%. The OilGuard wound cotton bypass filter had reductions for metal particles of 78-83%.

While I would like to see some repeats of these 500 mile filtering tests, most of the full flow filters did not do much to reduce the suspended particles in the oil. The Mobil 1 full flow filter was substantially better than the other full flow filters, but much less efficient than the single bypass filter in the test.

As of last March, the test author was planning to conduct a 5000 mile long test with a SuperTech FF filter/Mobil 1 oil/OilGuard bypass filter on his Jeep 4.0L inline 6 cylinder motor. However, he has yet to post these extended test results.

Mike_dup1 · Dec 19, 2003

I can speak from experience dating back to 1985 having installed by-pass in several vehicles since them.
My 1992 Chevy shows no oil pressure drop using the dual by-pass filters. I have observed the filters in cold weather. The full flow filter will get warm first and then the bypass slowly warms up as more oil is diverted to it for cleaning.

quote:

Working in conjunction with the engine’s full-flow oil filter, the AMSOIL By-Pass Filter operates by filtering oil on a "partial-flow" basis. It draws approximately ten percent of the oil at any one time and traps the extremely small, wear-causing contaminants and water that full-flow filters can’t remove.

[ December 20, 2003, 08:44 AM: Message edited by: Mike ]

msparks · Dec 19, 2003

If you want to see some by-pass filters mounted I have some on my website and Amsoil has some as well.

Here our mine.

http://www.lube-direct.com/bypasspage.html

http://www.amsoil.com/bypassfilters/index.htm

I have some dealers with over 100,000 miles on a PSD with no oil changes. If you want to talk with them let me know.

you can email me or call toll free
[email protected]
877-464-8798

Mike_dup1 · Dec 19, 2003

Some nice installs. The bottom of page photos gave me some ideas how I can mount one in my 2001 GMC 4x4 E. Cab. No room under hood and mounting them hanging down in not an options I like.

Got to go turn on heat in shop and plan this out. Darn, more work.

msparks · Dec 20, 2003

quote:

Originally posted by Mike:
Some nice installs. The bottom of page photos gave me some ideas how I can mount one in my 2001 GMC 4x4 E. Cab. No room under hood and mounting them hanging down in not an options I like.

Got to go turn on heat in shop and plan this out. Darn, more work.

Mike, I know where you can find a high quality mount for the underside if you interested. Send me a pm and I'll give you the link.

[ December 20, 2003, 04:26 PM: Message edited by: msparks ]

greencrew · Dec 20, 2003

quote:

Originally posted by mangusta1969:
Greencrew,

Typo in your post?? I think you meant to say "I see less wear particles filtered out for the full flow filters".

Yes, I think faster than I can type. The link shows less wear particles for the by-pass filter, so that is more where I was going. My thinking on this is that the by-pass filters wear-causing contaminants out of the oil which results in less wear metals which are another wear-causing contaminant. That's how you get an oil that results in a wear rate that is so close to 0 that you might just as well call it none.

I do understand that three will be small particles that can't be filtered out, and will show up on the used oil analysis and particle count. I have until May to figure this out before I do my own used oil analysis and particle count on the oil in my Dual By-pass at about 15k.

mangusta1969 · Dec 20, 2003

Slalom44 makes excellent technical observations here and I agree with everything he said.

Keep in mind that as an engine ages and its bearing clearances increase in size, it will require more oil flow to maintain the same pressure. This is why older engines frequently have less running and at idle pressure than newer engines.

Unless an engine's oil pressure is always being moderated by the engine's internal pressure bypass valve, the engine's passages and bearings can typically flow more oil than the oil pump can produce. Since (with the exception of engine warm-up) I don't know of any production auto engines that are pressure-controlled by these valves, I don't like anything that reduces the oil flow/pressure by even a small amount.

I would just feel better about the Amsoil Dual Bypass Filter and any similar devices if there were some published pressure and flow (in gpm) figures available for them. I would also like to know about the design of the internal restrictor valve (bypass pressure, max flow when fully open, size of oil passage, etc.). Does anyone have such information available for the forum?

slalom44 · Dec 21, 2003

I'd like to comment on the pressure drop issue, since there appears to be some misinformation out there.

First, I don't believe that Bob's testing and/or results are flawed. They tell us what we want to know about the drop in pressure through a DB setup. Nice to know, but it does not measure the effect it has on actual engine oil pressure since the test was not designed to do that.

In every engine that I'm aware of, the oil pump is a mechanical pump that pumps oil at a relatively contstant flow rate. Unlike an air compressor that builds up pressure, an oil pump pumps a relatively constant flow rate of oil regardless of the back-pressure (as long as it does not exceed the bypass valve pressure designed in most engines).

Pressure drop across a filter is important because it can tell you how sensitive that filter is to activating its internal bypass valve if the media gets restricted and/or oil flow is very high.

Since oil pressure is always measured after the oil filter (but before the oil galleys), you are actually measuring its resistance to flow through the galleys. Given a viscosity, that means that you are indirectly measuring the flow rate of oil to the galleys.

There is a misperception that the increased resistance across the DB setup significantly affects the flow of oil. This is not true for obvious reasons. Oil pumps aren't separate underpowered electric motors that bog down flow with increased resistance. They are powered by the camshaft (in most cars) and therefore the flow is relatively constant regardless of backpressure at the oil pump.

Oil pumps operate by the turning of eccentric "gear teeth" that squeeze the oil to create oil flow. It is true that as back-pressure increases in the pump, some of the oil doesn't get squeezed through, resulting in a small loss of flow. That would explain the few PSI drop that people have experienced.

Engine manufacturers could care less what the oil pressure is in a car. What they really want to know is the oil flow. But reliable flow meters are not practical, and so using oil pressure to indirectly measure how much oil is going through the galleys is the next best thing.

This is why the DB setup works, and the guys at Amsoil knew this when they designed and built the Dual Bypass filter setup. I just bought one, and can't wait to install it in my car!!

greencrew · Dec 24, 2003

quote:

Originally posted by mangusta1969:
I would just feel better about the Amsoil Dual Bypass Filter and any similar devices if there were some published pressure and flow (in gpm) figures available for them. I would also like to know about the design of the internal restrictor valve (bypass pressure, max flow when fully open, size of oil passage, etc.). Does anyone have such information available for the forum?

I wonder why they don't test and publish that information. I wonder if the numbers are such that they won't do anything to help support of sell more product. I'm sure if they were fantastic numbers they would be used in marketing.

As much as I'm interesting in seeing these numbers, I wonder if they would tell us anything. The bottom line is still the health of the oil, and wear on the engine, and results have proven to be solid for both when a by-pass filter is used. I have not seen a used oil analysis from oil run with the dual by-pass design that anyone has been less than very happy with. I know of no one who has been happy with the performance of any by-pass filter setup.

Gary Allan · Dec 26, 2003

quote:

I wonder why they don't test and publish that information. As much as I'm interesting in seeing these numbers, I wonder if they would tell us anything.

I think you answered your own question. Any testing would be arbitrary and indifferent to the particulars of any given application. One engine may have a very low oil pressure due either to low relief spring settings ....larger oil passages ..etc. ..while another will have a high volume pump and relatively small oil passages. How would the end user integrate such data? If I told you that the Amsoil dual bypass filter dropped 30% in pressure across it in the 5 gpm test ..would it mean anything unless EVERY other filter manufacturer conducted the same test for an "apples to apples" comparison?

RavenTai · Dec 26, 2003

quote:

Originally posted by slalom44:
there is a misperception that the increased resistance across the DB setup significantly affects the flow of oil. This is not true for obvious reasons. Oil pumps aren't separate underpowered electric motors that bog down flow with increased resistance. They are powered by the camshaft (in most cars) and therefore the flow is relatively constant regardless of backpressure at the oil pump.

slalom44 a lot of what you say is true the pump itself is positive displacement and for a certain rpm will deliver a certain volume of oil almost regardless of back pressure (as you explained well)

but it has a pressure relief vale, the more upstream restriction the more oil is relieved and sent back to the pan,

the spring and ball restrictor in the Amsoil DB is a differential pressure regulator ensuring a set differential pressure, does not matter how hot or cold or viscosity the regulator will extract a set amount of pressure drop, if the differential pressure on both sides of the restrictor gets to high the oil overpower the spring and pushes the ball towards open the oil flow in and the pressure on the downstream side gets higher reducing the difference in pressure, the spring pushes it towards closed, the second stream through the bypass filter cannot make up for this loss in flow and pressure as the regulator will not allow it, it just moves more closed until the balance in differential pressure is found

this lower pressure in the galleys is lower flow out all the lubricating orifices more and more of the volume that the pump made out of the pressure relief valve strait into the pan

many people have installed these systems and none has reported the large drops that bob saw but many people have seen drops in pressure.

trading pressure, flow and $ for easy install is not a good buy so I went for a traditional bypass install

slalom44 · Dec 26, 2003

quote:

Originally posted by RavenTai: but it has a pressure relief vale, the more upstream restriction the more oil is relieved and sent back to the pan.

I may be misinterpreting what you've said, but the engine's internal pressure relief valve isn't a variable flow valve. It is a bypass valve that starts opening up only when the backpressure at the bypass valve is very high, preventing potential damage to the oil filter.

During normal driving, this valve would never open. Even at startup on a cold day it wouldn't open. I'm sure it's different for different cars, but I'd guess that it's set to open up somewhere around 100 psi on most engines and higher on high-performance engines.

I may be wrong but the way I see it, if (for example) the engine's pressure relief valve would start opening up at 7000 rpm with a particular grade of motor oil in a particular engine, then using the DB filter setup the pressure relief valve would probably open up closer to 6500 rpm. This might reduce the maximum oil flow when you are approaching redline, but at those RPMs, your engine is pumping far more oil than the engine needs.

For those using a single remote bypass filter: Unless you are using a sandwich adapter for the return flow of the bypass filter you are going to see a drop in oil pressure (and oil flow) at all RPMs because the oil going through the bypass filter doesn't go through the galleys. But again in my opinion this is not a problem either because the engine pumps far more oil than it needs.

So I don't see the dual remote bypass filter as a compromise. On the contrary, for the way I drive my car I see it as a system that provides the maximum flow of oil through the galleys with the greatest percentage of oil passing through the bypass filter.

RavenTai · Dec 26, 2003

nope no misinterpretation you got it,

hmm perhaps there is a major difference from motor to motor of pump flow and relief valve settings, I had not though of that, I have been thinking of what I see on my truck and what I was taught of aircraft engines,

IF the motor in question always has its relief valve closed then it would be as you say, all oil pumped is delivered to the moving parts, that would make a big difference

when I start my truck cold the oil pressure goes strait to 70 even at idle, as I drive the oil pressure stays at 70 as long as it is above 1,500 rpm the only time that relief valve closes is warm idle where my oil pressure is around 25psi, making the relief valve (in my case) variable and set to about 70psi But you are correct that when the relief valve is closed (at and just above idle) the the small amount of oil bypassed decreases what is sent to the moving parts, for me this was a better choice than a permanent restriction of main oil flow, but if indeed yours is different that would not be the case

do me/us a favor find out where your oil pressure sending unit is in relation the the oil system components, if it is at the preferred location after the oil filter (and therefore after the DB) watch your gage for a wile (cold warm and at different RPM's) before and after the install tell us what happens

I am not sure what you mean by:

“It is a bypass valve that starts opening up only when the backpressure at the bypass valve is very high, preventing potential damage to the oil filter.”

you put in in Italics so want what it to have extra attention, on my truck and other oil systems I am familiar with the pressure relief vale is located as part of the oil pump or very close to its output, the filter bypass valve is near the oil filter, one regulating oil pressure the other bypassing the oil around the filter should it become clogged or cannot handle the flow “dirty oil is better than no oil”

[ December 26, 2003, 07:46 PM: Message edited by: RavenTai ]

Dual bypass filter

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