Oil filters that restrict oil flow

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all filters restrict flow.That is why there is a bypass valve in the filter or the engine oil circuit. There wouldn't be a real big drop in oil pressure ,Some where in the oil filter section Bob the oil guy him self did an oil filter test showing pressure drop. The test drew lots of interest ,I think it gives an idea of what kind of drop happens.

[ August 12, 2005, 04:20 PM: Message edited by: Steve S ]
 
If you have a reaaaalllllyyyyyy good guage maybe.

Considering the usual oil flow restriction for a new filter is in the 1 psid range, you'd need a great guage to tell the difference.

However, your oil flow.....is regulated by a mechanism within the oil pump.
 
Sorry for expanding this topic a bit:

the latest Amsoil "action news" states on page 4 of the Donaldson filters section: "Endurance oil filters significantly lower restriction than conventional cellulose filters. During the engine warm up period, an Endurance oil filter allows the oil to flow through the filter at a colder temperature than a typical cellulose filter. The additional filtering time decreases engine wear."

Also, Mobil has already marketing that their new Mobil 1 oil filters will permit greater flow (see website) than the current Mobil 1 filters. Apparently Exxon-Mobil thinks its important.

"Less engine wear"...Maybe something to it.
 
jbas...

Restriction of flow is a "relative" term.
A filter needs a media to do it's job.

There are three types used in automotive oil filters.

Cellulose----paper

Synthetic----commonly referred to "microglass".

Blended media where by the main ingrediant is cellulose with a certain % of synthetics blended in.

In a lab one can determine the restriction of the element and to what %.

Sythentic media is less restrictive than Cellulose.

Another form of restriction is TO much media within the filter can. ( the old cut and compare how many pleats are there routine). The more pleats, the more restriction. The media itself will add to restriction regardless of which type of media it is.

So Amsoil and Donaldson are correct in that synthetic media is less restrictive than "cellulose". What they don't mention is that most every oil filter on the market made by US filter companies is not longer straight cellulose which is their base point of reference. They are a blended media. Which is also less restrictive than straight cellulose. But not to the degree of a straight synthetic.
So it's all relative to what you want to use as a basis point in your reference.
 
quote:

If I install a filter that restricts oil flow will I have a lower reading on my oil pressure gage ?

Possibly ...but mostly unlikely. FG has it about right on the pressure drop across a filter. It typically doesn't amount to squat.

Let me restate that: Yes, if you have a filter that restricts flow, you will have a lower gauge reading. Getting that to occur would be "odd". Filters typically don't restrict flow, they cause changes in velocity that is shown with pressure elevations (or drops, if you prefer).

Now if you have a 200k engine ..where the oil pump has clearances that allow a great deal of internal leakage ..and you're barely providing enough flow to keep things "sound"....then sure, it can impact flow. Otherwise the idea if mostly bogus.
 
Here's my .02:

The idea isn't as bogus as it might seem if we re-phrase it a little. A low-restriction filter, as noted above, ensures rapid oil pressure at start-up before oil warms and may keep iron or other metal readings down.

And synthetic filter media is spec'd as "Extended Service/Heavy Duty", when conventional media is not, the synth version is a whole different part number. The FL1A/PH8A sized BALDWIN B2-HPG (High Performance Glass), DONALDSON P169071 (Endurance)and FLEETGUARD LF-3487 (Microglass) have no proper cross-reference to anything by the usual FRAM, K&N, AMSOIL, etc, as a lesser filter is spec'd for those applications. The WIX 51515 is also of the same spec in all other regards but is not, and cannot be, properly cross-referenced.

As to money, I get the BALDWIN for $6.75/ea at 12 per case, and the other two are about $15.00/ea retail, individually.

That -- along with REDLINE, regular ARX cleaning, and otherwise continual use of LUBE CONTROL and FUEL POWER -- gives me some piece of mind (until the next UOA comes along) that water or dirt contamination can be handled.

The HD synthetic-media filter is as vital as the quality fluids/OCI and scheduled maintenance IMO.
 
quote:

Originally posted by TheTanSedan:
The idea isn't as bogus as it might seem if we re-phrase it a little. A low-restriction filter, as noted above, ensures rapid oil pressure at start-up before oil warms and may keep iron or other metal readings down....

I disagree. Engine oil pumps are "positive displacement" pumps. This means that except for some leakage that Gary Allan mentioned, they pump the same amount of oil regardless of backpressure at the pump. This is, of course, assuming that the backpressure is less than the engine's pressure relief valve setting.

Therefore a low restriction filter media will allow more oil to pass through the filter media rather than going through the bypass valve unfiltered. It will not give you rapid oil pressure at startup.

quick oil pressure at startup can be obtained if the oil stays in the filter and galleries, and does not drain out. A good ADBV will allow this to happen. So when the pump starts turning, it isn't wasting precious time filling up empty cavities.

I should mention that some oil pressure senders are located post-filter, while others are located before the filter. If located post-filter, it is measuring the difference between ambient pressure and the pressure in the system after the filter. When I installed my BMK-13 bypass filter in my car I saw essentially no drop in oil pressure (measured post-filter) even though there is a significant drop in pressure across this setup. This is because the flow hasn't changed, but the backpressure between the oil pump and the filter is higher. If my car had a pressure sender located before the filter instead, it would show a significant increase in pressure but the oil pressure the engine actually gets would be the same.
 
That's my take on it, '44
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