The reason many of the manufacturers don't have a lot of concern about the bypass section as it rarely comes into play. If the full flow part becomes completely clogged, usually by negligence, then the oil goes through the bypass section in order to prevent oil starvation in the engine.

However, if you just want to do an even finer filtration of your oil, then another filter system will do the trick.

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Sam

84 300SD 350K+ miles ( Blue Belle )

You are describing a bypass valve, not a bypass filter. The bypass section of the filter is always working.

I am describing a bypass valve and some "bypass filters".
Some full flow oil filter designs have a bypass valve, and anti-flowback valve, integral to the filter and when the filter becomes clogged, it allows unfiltered oil to prevent oil starvation of the engine.
Some full flow oil filter designs have a bypass valve on the engine to accomplish the same concept. This design also has an anti-flowback valve located on the engine.Since I did not see either a bypass valve or anti-flowback valve on the filter cartridge, I suspected the latter.

Some two-stage or bypass filters have a "fine" full-flow and an "ultra-fine" bypass section. Some have a "fine" full-flow and "coarse" bypass so that there is at least some filtration of the oil rather than un-filtered. Given what I see in the filters, I suspected the latter in this case also.

Now I haven't studied the oil system on this car but maybe someone has. You tell me.............

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Sam

84 300SD 350K+ miles ( Blue Belle )

I cannot answer for Forced Induction or on other filter setups but I am the best qualified to answer for my setup.
If the extra filter I installed becomes plugged up the oil flow from the oil pump will continue to go through the full flow part of the lower portion of the stock filter and continue to go through the upper portion of the stock filter (the bypss portion of the filter) through the orfice in the hollow stem that is attached to the filter cap and down passed the stem check valve and into the crankcase just as it would if I had not installed my extra filter.

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84 300D, 82 Volvo 244Gl Diesel

The oil that goes through the bypass filter goes through the very small restriction orifice and straight back to the oil pan.

Forced Induction already answered part of this; but what I would like to say is that If you manufacture an oil filter you ought to know how well it can filter. I am talking about quality control. How do you check the filters you make to see if you are putting out good quality if you do not have
any sort of standard that they have to perform to?

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84 300D, 82 Volvo 244Gl Diesel

Generally reputable manufacturers will do selective analysis of a product on their production line from time to time as well as extensive tests of the prototype prior to putting it into production. So its likely it will perform to its intended applications.

I am sure there are standards that filters have to meet too....at least I hope there are. You can always analyze them yourself too to make sure they are working properly. But that could be expensive. $$$

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

On the oil filter in my car there is a lower full flow portion made of pleated paper media; the companies can and have told the micron ratings on that portion of the filter. They are speechless on the rating of the upper bypass portion of the filter; I think it is because the do not know the performance of this part of the filter.
While I could have an oil analysis done on the crankcase oil I have no way of testing the performance of each of the separate parts of the filter by themselves without building some sort of test bench; which I do not plan to do.

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84 300D, 82 Volvo 244Gl Diesel

I believe in the massive oil filter thread it was found that the typical upper bypass section of the stock filter ranges from 15 micron (Baldwin dual pleated paper style) to 25-30 micron for the packed cotton material. Once I run out of Fram filters I am going to switch to the Baldwin filters and call it good enough.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

This infomation is in some of our other threads and also in the Manual.
The Bypass Section of the Stock Oil Filter has nothing to do with the Bypass Valve that is built into the Oil Filter Housing.

The normal pressurized Oil (the Full Flow section of the Oil Filter gets Oil from the same area) on the out side of the Filter goes through the bypass Section of the Oil Filter and through an about 1/16" hole at the top of that Tube that goes down the Middle of the Oil Filter Cap.
You can see that Hole when You pull off the Cap during an Oil Filter Change.

The Oil continues down the Tube and goe by a Spring Loaded Check Valve that is inside the lower end of that Tube and from there the Oil goes Back to the Oil Pan.

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84 300D, 82 Volvo 244Gl Diesel

UPDATE- I was getting a little oil seepage around the top of the dip stick tube. I added a piece of 5/8 heater hose. One clamp clamps it to the dipstick tube the other clamp clamps it to the 3/ rubber hose with the 3/8 tubing going through it.
I was at the junk yard today and picked up another valve cover oil filler cap and will try drilling a hole through that to relocate the return oil from the dipstick tube to that cap.

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84 300D, 82 Volvo 244Gl Diesel

Update.
11-04-2010 I removed the Bypass Oil Filter set up that I installed at the beginning of this thread and replaced with a homemade Filter Housing that uses a 0.5 Nominal Micron cotton string wound Filter Element.
(The reason for making my own housing is a real one for that type of Filter element is quite expensive. However, once you have a Housing the Filter Elements cost about $3 each when you buy a case of 12.)

I also relocated the Bypass Filter Oil Return line from the Dipstick Tube to a tube that I drilled and mounted in to the Bolt that is item #94 in the drawing of the Engine.

1 pic shows the housing and Element and the other shows where I mounted it.

The last 2 pics show what the Filter looked like after being used for 1 year with an 1 Oil Change during that time but the Bypass Filter Element not changed till today.

In the last pic on the right you can see some thing has built up on the out side of the Filter element showing that the Filter is working.

Attached Thumbnails

         

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84 300D, 82 Volvo 244Gl Diesel

What keeps the end caps from leaking?

That is a good question. I was supposed to source out square cross section O-rings but never did.

The first time I put it together I filled the O-ring grooves with Silicon Sealant. I did that because I thought I might have to make some further modifications on it so I needed it to be easy to take apart.

When I changed the Filter I decided to Epoxy the Filter Base with JB Weld but am still using the Silicon Sealant on the Top Cap where I pull out the Filter.
I thought about welding the Base to the Tube but it was clear that it was going to end up for my own personal use and I did not feel like dragging out my Welder.

All of the above seems a little rinky dink but it works and I do not mind doing it.
Like I said in previous posts the Oil Filter Housing is not ready for any sort of commercial sales and it is certainly going to take some major redesign to make it so.

Another issue is that if you take a look at the Filter Element you see that the inner Tube needs extends beyond the Element. That tube needs to go into a groove on both of the end Cams and there has to be enough compression on the Sting part of the Element to seal it.
That took some careful measuring and when the Element is inserted you have to make sure the Tube goes into the groovs (it needs something betgter to guide the Tube into the grooves).

I keep searching eBay for a commercial Filter Housing (they call it a Filter Vessel) so I can see how it is really supposed to be done but so far they are too expensive.

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84 300D, 82 Volvo 244Gl Diesel

1 pic shows the housing and Element and the other shows where I mounted it.

The last 2 pics show what the Filter looked like after being used for 1 year with an 1 Oil Change during that time but the Bypass Filter Element not changed till today.

In the last pic on the right you can see some thing has built up on the out side of the Filter element showing that the Filter is working.[/QUOTE]

D911, think I'm going to use your idea for a return line, makes perfect reasoning!
That way the return is giving extra lubrication to the chain, some may make it around & back to the top of the engine.

What is the thread & size of that bolt? Did you replace the bolt w a fitting?

Thanks,
Dave