BOBISTHEOILGUY FILTER TESTS

[Michael SR]

quote:

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Originally posted by satterfi:
I don't know if most oil pumps have internal reliefs or not. I don't see how it matters if the relief valve is internal or external. They are set to control max system pressure, like 85psi. Maybe I don't understand your point.

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i was the one who didn't understand. i realized my mistake after re-reading your post.

however, given a clogged enough filter, the flow rate through the engine will indeed change. if the restriction is high enough to cause the pump to bypass, oil that would otherwise go through the engine is now just circulating through the pump.

an extreme, sure...

on the subject, it's amazing how much those pumps flow. i've seen 2 where the bypass stuck closed. one ballooned a 300psi burst rated racing filter enough to unseat the gasket. the other blew a regular oil filter like a tactical nuke went off inside. (it's amazing the oil pump driveshafts can live.)

also seen them with the bypass stuck wide open. in a ford 302 (the type of pump bob used, if i remember correctly), this caused idle pressure with hot oil to be ~2psi, and 2000rpm pressure about 20psi. actually, not bad, considering...

-michael

 

[Michael SR]

quote:

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Originally posted by OneQuartLow:
Michael, I'm also seeing interesting differences that make me suspect the varying specs for internal clearances. I've only tested two pumps so far (Melling Mopar 318 and Jeep 242) but while I'm not ready to name numbers I am confident there's significant loss from this factor, increasing at higher pressures (even with the relief valve disabled). No doubt this means ordering OEM pumps for comparison. Eventually. It'll never end.

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oh, sure, they're all different. i used to take the time to blueprint them. on a few i even "ported" them in addition to the blueprinting.

those types of mods raise oil pressure to the block. that means, i guess, that output flow goes up without the bypass regulator seeing a pressure change.

fwiw, OEM pumps seem the best overall, to me. certainly the stock aluminum-bodied ford 302 pumps beat any aftermarket jobs, and ditto the sbc pumps installed on LT1/4 engines. if you disassemble them, the clearances are all almost perfect.

-michael

 

[MolaKule]

For what it's worth guys:

Shigley and Mischke, in "Mechanical Engineering Design,"
show that the oil flow required to maintain a 28 F differential between oil-in temp and oil-out temp of a bearing of 0.00175" clearance, is Q = 0.252 m^3/s for SAE 20 weight oil, at a shaft speed of 1800 RPM. This is for a bearing D = 1.5" and Length = 1.5." The lubricant temp is 130 F.

A Chevy main bearing in a 350 V8, by comparison, has an average clearance of 0.001925", a length of 1.21875", and a diameter of 2.448".

[ April 15, 2003, 05:44 PM: Message edited by: MolaKule ]

 

[satterfi]

MolaKule

.252m^3/s is 3995gpm

 

[TooSlick]

Nice work Bob!

I have a couple of suggestions:

1) Heat the oil to 190F-200F - a 10w-30 is fine ...
2) Increase the supply side pressure to a more representative pressure of 60-80 psi. Many high performance engines like Acuras and VW's run much higher oil pressure than 40 psi, even after fully warmed up.
3) Test a 40wt or 50wt oil for comparison to look at flow rates and pressure drop.

TooSlick

 

[jason07-1zzfe]

Rather than try to heat the oil wouldn't it have been easier to get some SAE test oil? They have an oil that at room temp it simulates a 30wt at operating temp. I.e. it's around 10-12cSt at room temp.

Also, maybe I missed it, but I think a flowmeter is very important here. And adding the back pressure after the filter is not necessary. What we need to know is the differential pressure at specific flow rates. Also need to know the viscosity at those points.

[ April 16, 2003, 09:44 AM: Message edited by: Jason Troxell ]

 

[Mike_dup1]

Testing is just testing, its real world results that count.

There is no way to test for all operating conditions. Not only would you need to do all the things mentioned but maybe you should also run the same tests using all the engine oils and viscosity's too? Not only that, but sampling just one of each brand filter may not give reliable results. Seems to me to be conclusive you would have to test multiple versions of the same part number to get consistent data to base a conclusion on. Then you would have to determine if you are testing the current production version or an outdated version.


You can really get carried away here and what does it accomplish?

 

[jason07-1zzfe]

quote:

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Originally posted by Mike:
Testing is just testing, its real world results that count.
...Not only would you need to do all the things mentioned but maybe you should also run the same tests using all the engine oils and viscosity's too? ...
You can really get carried away here and what does it accomplish?

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Different oils will not affect differential pressure.
Increase in viscosity will increase differential pressure. There is probably an equation to calculate it somewhere once you have a baseline. No need to test all. But it is irrelevant anyway. Say you have 2 filters, one has a lower pressure drop than the other...this fact will not change with change in viscosity. It will ALWAYS have a lower pressure drop.
What do you accomplish? Determining which filter is the most/least restrictive. Simple as that.

Additionally, if you have the flow and viscosity information I suggested, and you know your engines flow rate, you can determine if and when each filter may go into bypass.

[ April 16, 2003, 01:30 PM: Message edited by: Jason Troxell ]

 

[jason07-1zzfe]

Another idea after the initial clean restriction testing is completed:

Start testing USED filters at increasing drain intervals intervals say 5k, 7.5k, 10k, 12k, 15k... To determine when the filter actually becomes a significant restriction. This would be an even more interesting test to me.

Then after you test one brand you could try others to see if their increased capacity claims are true.

 

[bigorange30]

Any more new data lately?

[ April 16, 2003, 03:23 PM: Message edited by: bigorange30 ]

 

[joee12]

quote:

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Originally posted by bigorange30:
Any more new data lately?

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Bigorange, we are currently trying to rework and change the setup, we will keep you posted, Joe

 

[YZF150]

Testing is just testing, its real world results that count.

Yes, that is stating the obvious.

I just opened every page of messages on this forum--16 of them--that date to May 31, 02. There is not a single post besides this one that has four pages of replies to the original post. I submit that this topic is generating some extraordinary interest.

So, yeah, it's just testing. But we're finally getting somewhere. The investigators have already demonstrated some rather significant pressure drop differentials in filters. I consider that to be an accomplishment. It's a start, and it's valuable to me.

 

[turbochem]

quote:

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Testing is just testing, its real world results that count.

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So...there is:

a) Testing
b) Put it on your car and see if it works. Well, you really won't see much. For all you know, there could be no filter media!

Single pass efficiency is just testing...
Double pass....just more testing....

I think a small amount of light is better than being completely in the dark.......

The same could be said for UOA's............just tests.....

 

[Not the Autorx Frank]

I am not by any means a hydrolic engineer but I am willing to bet that a drop in pressure may not reflect a severe flow difference. Also, wouldn't it make sense to try them with dirty oil? I bet oil at operating tempurature an somewhat dirty may bring different results. So if flow is the key we will have to wait and see the new tests. So we can compare filtration vs pressure vs flow vs price vs availibility vs durability vs reliability. Goes to show ignorance is bliss.

 

[turbochem]

quote:

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Goes to show ignorance is bliss.

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And why all those 10min. lube places make a fortune!!

I wonder what it's like not to worry about such things as oil and filters......

...must be a simple life....

 

[Not the Autorx Frank]

I mentioned this a while back, Hi my name is frank and I'm an oilaholic. I have been using whatever oil is on sale for 236 days. Just kidding Mobil 1 all the way!!!!!!!!. no offence to AA man. Good folkes!

 

[S2000driver]

I'm chiming in here a little late, but is there the capability to test pressure drop at varying flow rates?

Although measuring pressure drop at a stable point conveys some interesting information, it's much more informative to be able to examine the way the oil filter responds to changes in flow through graphing pressure drop vs. flow rate.

This would convey much more about what is really happening in the filter at any given flow rate.

 

[quadrun1]

Hello Bob,

Very interesting test!

I notice you're using filters with thread size 3/4-16. I have some filters in my collection with that same thread size, could I send them to you for testing?

1) Purolator L25230, which is the similar to the Purolator L20195 you tested, except that the L25230 has a higher bypass valve setting (20 psi vs 11 psi, I believe)

2) Mobil 1 M1-102, which is the short version of the M1-209 I believe you tested. The results should be interesting to those wanting to use oversized filters.

3) Bosch Premium 3330, which again is probably the short version of the Bosch filter you tested

4) A UK-made ACDelco PF53, a US-made ACDelco PF53 (Champion Labs), and an ACDelco Ultraguard Gold UPF53 (Champion Labs). ACDelco claims that the UPF series filter well *and* also flow well--it should be interesting to see the results.

Let me know if you can test them, and I'll mail them to you ASAP!

Thanks,
Jason

 

[Fillherup]

quote:

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I am not by any means a hydrolic engineer but I am willing to bet that a drop in pressure may not reflect a severe flow difference.

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Good question!

Is this true? It seems to be true for varying size hoses. But hose size is a constant in this test, is there a one-to-one maping of flow vs PD? If not, does someone know the relationship?

It seems if the relationship is not one-to-one are we not missing the goals of this test? Isn't oil flow the real interst?

[ April 19, 2003, 07:58 PM: Message edited by: Fillherup ]

 

[Alex D]

BOB ....what is your plan to continue the testing.......right now we are all jsut shooting the breeze here.......it would be nice to see what you are doing now......