Restrictor size for bypass oil filtration?

[AcIdBuRn02ZTS]

Hey guys...

Those of you running bypass filters, how large of an orifice does your filter head or restrictor fitting use? The filter head I'll be using doesn't have a restrictor and I don't want to be limited to certain filters.

The filter I'm using for now (or will be once plumbed) is a Fleetguard LF777 bypass filter. The filter does have a built in orifice but I believe it may be too large still.

I can purchase npt threaded restrictors from mcmaster-carr but being as they are $10 each.. I don't want to guess too many times.

I want enough restriction to keep from dropping oil pressure at hot idle, yet enough flow to be worth while.

Thanks
-Chris

 

[AcIdBuRn02ZTS]

I'm thinking around a .040 which should equate out to roughly 1qt per minute of flow which would filter the entire capacity of the engine every 13-14 minutes give or take... which from what I'm reading, is about right.

 

[Thewespaul]

What head are you using for the bypass filter head? I would get an oil pressure gauge and buy a few different sizes and use the largest one you can use without noticing a difference in oil pressure. Otherwise every setup is going to be different as far as what orifice will work.

 

[AcIdBuRn02ZTS]

I've got a mechanical gauge... using a Fleetguard filter and filter head.

I want to avoid buying multiple restrictors as they are $10 each... so just trying to see what others have used. I'm more then likely going with a .040 or .036

 

[Thewespaul]

From a little research that seems about right, the amsoil kits use a .03 size restrictor.

 

[BrianX128]

I use a .060 restrictor and haven't noticed any loss of oil pressure. The thing I bought from jegs had a .040, .060, and if you didn't thread either of those in the fitting with an Alan key it left it as .080 or something I can't remember which.

 

[AcIdBuRn02ZTS]

Based on mcmaster-carr's website, @40psi, .060 would flow ~ .5gpm of water which oil has a correction ~1.05 meaning .525gpm.

I'm wanting to half that... get as close to 1qt per minute as I can.

In theory, the sweet spot will be around .038 which is where I'll start. Not worried about plugging it up as it will be on the return side of the filter head.

Anyways, thanks for the input.

 

[icanfixall]

I suggest buying the smaller size restrictor. then if its too small drill it out till it meets with what you want. How hard will it be to fabricate your own restrictor to fit the opening in the bypass head.

 

[AcIdBuRn02ZTS]

Not sure of a fitting I could use to make my own. I know some drill pipe plugs for the restriction... but not sure how I'd put a pipe plug inline with the outlet and still have threads for the hose fittings...

I suppose one could take a steel pipe nipple and weld it solid... then drill it. I would worry about the weld eventually failing though.

 

[AcIdBuRn02ZTS]

Well... .036 is too small. Lol

It currently takes 3 minutes to flow 1/2qt of oil... way too slow considering the system now holds 14qts.

Will more then likely just step that up to 1/16 but doing some reading on it first.

 

[OLDBULL8]

If you measured the flow at idle, you may be surprised how much more flow at running RPM (2000) there would be.

At 1/16" = .0625 might be to big. I would use a 3/64" drill,. then check your flow.

Here is drill sizes, Numbers, Letter and Decimal.

http://www.auto-ware.com/techref/drillsizes.htm

 

[AcIdBuRn02ZTS]

I'm gonna post up over at BITOG and see what they say about the flow rate. It may be fine... just seems really slow. I know that the filter is substantially more efficient the slower the flow.. so that's not a bad thing.