Max Flow Rate

[Taylor]

I recently put a high vol oil pump in, and I was just wondering about the max flow rate of the filter which is 7-9 GPM. With the high vol oil pump @ redline the flow should reach ~17 GPM, will the filter limit the oil flow?

also I was looking to use a bigger filter, I found a larger one but the nominal micron rating is 30, whereas the stock is 20, is that a problem?

 

[Gary Allan]

Are you SURE that it peaks out at 17gpm?? That's up there in Power Stroke range. What is this engine??

A filter will develop (YMMV) something like 10PSI drop across it at 10gpm (there's a visc spec there too). That is, at 10gpm the fluid will produce 10 psi (or whatever it is for that filter) with the other side of the media being at atmospheric.

This rating rarely has any meaning since long before you ever reach 10gpm ...your oil pump relief valve is engaged. Naturally, there are exceptions with some exotic or unusual installations.

My HV pump allegedly produces 9gpm @ 3500 rpm. With a 58lb relief, it requires me to use 5w-20 if I'm going to "fit" all the oil through the engine at operating temps. My engine would normally only consume about 5gpm MAX.

I'd plan on 0w-0 oil with that flow rate (not what I'm really saying here).

There's also some other physics that takes hold as rpms increase. Are you really pressurizing the journals? Or just feeding the hopper that's drawing the oil in (visions of some ink injection on some printing roll).

 

[Taylor]

3gpm @ 900 rpms 68# bypass is what the pumps rated at, redline at 5,250. ~17.5GPM? I could be wrong happens to me a lot. I use 0w20, and my motor does not see 68 psi

A filter will develop (YMMV) something like 10PSI drop across it at 10gpm (there's a visc spec there too). That is, at 10gpm the fluid will produce 10 psi (or whatever it is for that filter) with the other side of the media being at atmospheric.

can you explain this a little better?

also if the bypass psi on the filter was a bit lower than factory would that matter?

 

[Taylor]

its a jeep 4.0, just looking to put on a bigger filter. Ive been using the ford 5.0 filter, but plenty of room to go bigger. Guess its a bit overkill but i was thinking about (if need be) changing thread adapter to accommodate a larger filter. the ea026 will screw right on same specs except its nominal micron rating is 30 whereas the factory filter is rated at 20. I know you have a 4.0 what filter do you use? and are there any better ways to search for a filter that will work by say gasket size? thanx again gary

 

[Gary Allan]

Quote:
I could be wrong happens to me a lot.


Me too. At least (like me) you're not afraid to be spanked ..and eventually, you get a few things right.

Quote:
can you explain this a little better?



I'll try. Keep in mind that there's been a few gaps in my formal education ..so there may be some rough edges.

Filters do have a PSID spec to them. If you can find the data (not at all easy to find), it will give you a true comparative evaluation of the filter's resistance to flow over another. The problem with this is that it gives some impression of "better flow". Flow doesn't really depend on the filter ..but more on the pump relief limits. If your pump isn't in relief ..you lose no flow ..nor rate of flow ..nada ..zip..nothing. There's also the fact that the engine is many magnitudes higher in "resistance to flow" than any filter is. You don't develop 60 lbs of pressure across the filter. You develop (probably) 58 of it from the back pressure from the engine ..and (maybe) 2 from the filter. Once you're in pump relief, this all gets thrown out the window to some degree. Now your resistance limits for your filter are dictated by the impedance of the media ..and the bypass valve setting.


If you don't see your relief setting, you don't need to worry about your filter. The only thing that will produce any PSID will be loading and that will be variable depending on filter saturation. If you think about it, it's effectively making the filter smaller and smaller and will lower that gpm number that produces that PSID. It's somewhat reactive, since the visc of the oil at the moment will effect the differential.