Oil filter flow 22mm vs 3/4"?

[Pete C.]

Ahhhhhhmmmmmmm, What does the od of the stud thread, have to do with oil flow? The restriction is in the ID of the stud.

 

[labman]

Good point Pete. However, a larger OD allows a larger ID. In my calculations I was asuming ID's were the same percentage. Figure a constant wall thickness of say 3 mm. 22 - 2*3 = 16 19 - 2*3 = 13 (16/13)^4 = 2.29 or 129 % more flow for 22mm than 3/4'' at the same back pressure if the stud is long enough to obey the rules for flow in a pipe. Small changes in pipe diameter drastically change pressure and flow. Even more so in turblent flow.

 

[bulwnkl]

Chico80x, what kind of truck do you have? What engine?

 

[chico80x]

2006 F-150 SCrew 5.4L 4x4.

 

[Gary Allan]

Just to give you an idea of what presents a (typical) 2 PSID in your oil scheme...

Without too many exceptions ..that port you see @ 3 o'clock is what typically handles 100% of your oil flow. In rare circumstances it requires a very small hole drilled in it to handle higher volumes. The breaking pressure is 2 PSID.

 

[Filter guy]

Gary..is that a full flow filter head or a by-pass head?

 

[Gary Allan]

That's Permacool's normal (designed) oil cooler sandwich which is Ralph's modality of choice to install his bypass filters. The little poppet relief valve can usually pass the entire flow.

I was sceptical at first.... until I tried it in the field with additional (very small) holes. I was SO convinced that without them there was no way that that little poppet relief could do the job.

Note the the hex head @ 12 o'clock. There's also one at 6 o'clock ..but you're looking at the back end of it. Those are the plugs that I had to tap and install to get a differential.

I had a very hard time believing it without experiencing it myself.

Before that, I challenged everyone that used one. Ralph, in his wise rhetorical manner ...merely told me that it's rare ..extremely rare ..when an additional hole needs to be drilled to restore normal flow. He was, as usual, correct.

For my differential tests, I got rid of it. Welded it shut on one of my sandwiches ..and drilled, tapped, and plugged it on the other.

 

[Gary Allan]

This is, btw, one of my foundations for believing that, below relief limits of the oil pump ...there is no such thing as a restrictive filter. The oil has no choice but to accellerate through whatever it encounters. Since it's always going to be in series with the engine, it cannot have a substantial resistance to flow, as expressed in PSID anyway. The engine will always be the 800 lb gorilla in that comparison.

Open your relief valve at the oil pump

that's not the case anymore.

[ August 23, 2006, 10:24 AM: Message edited by: Gary Allan ]

 

[Gary Allan]

Post Script: Click me for that eye opening moment that hits us like a ton of bricks and alters our lives from that point on

 

[427Z06]

quote:

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Originally posted by chico80x:
I just installed an Amsoil dual by-pass system on my truck that also relocates the FF. But the FF that the kit requires uses 3/4" threads instead of the 22mm that the truck originally uses. So I'd like to know if the reduced size of the center hole on the filter I'm using now will flow less than the one that came with the truck from the factory? Thanks.

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I hope this isn't the same combination of by-pass system and truck that has suspicions of being detrimentally restrictive according to Terry.

 

[chico80x]

No, I believe I read that post and Terry was reffering to the Power Stroke Diesels, not the Ford 5.4L engines. At least that's what I think.

 

[Gary Allan]

Yes, apparently the PS has some unreal flow potential and demand. The filter itself has a 1.5" thread on it. No way you can match 1/2" lines up to it. I think the fullflow filter is rated for something like 30gpm