Oil filter bypass valve

[Will L.]

I would like to hear all sides of this. Nobody get hurt feelings and feel free to share what great grandpa said. Ask any question. What? My bank pin number? It is... wait a minute... not ANY question sheesh!

Not really trying to get into bypass filters. Just the main filter- whats best, worse and why.

Some oil filters have one and some don’t. Ones without normally have one in the block. currently about the best oil filter I have seen for 6.5 is the Wix 51060 and 57202. Same filter except the 202 has built in 15psi valve and listed for duramx, and the 160 has none and listed for the 6.5.

When building many other engines, some builders remove the block internal valve for better flow and go to the in fiter unit. On some engines this alters flow worsening it (it has been argued but I never seen it).
I have not chased this yet on the 6.5, and this conversation is the beginning of it.

Also from long term wear stand point, the spring tires and is less reliable after heat cycles, build up on sealing area, etc.

Going in the filter means a new valve every filter change, so no build up of contamination, and no aged spring/seal issues.

If a no bypass valve filter gets put on by mistake- you have no bypass...

Some people dont run any bypass in two optional ways-
1. No bypass allowed= 100% oil filtered, but plugged filter starves engine of oil. So an all or nothing gamble.

2. Nascar style. No bypass because there is no filter, only a wire mesh screen. Best lubrication for 1 day, but not so happy daily driver. I have looked into this and a bypass only filter- but decided against it. To risky for low reward.

Finally the double up. What happens if you have ine in the block and one in the oil filter?

 

[schiker]

This one is one of my never satisfied areas of clear understanding. Especially when running a remote oil filter setup!

What happens at cold start, initial flow, or at engine rev ups? What about a warm start does viscosity change things a lot?

I had a GM technician tell me the oil filter bypass never open unless the media plugs up. Its hard to believe that ????

Let me start with oil pumps are a positive displacement gear pump. They have some slippage but flowrate mostly depends on rpm. At low rpm do they slip that much? They will internally pop off if it wants to flow more but has a restriction to flowrate at something like 80-90 psi resistance to flow. Not sure if its so they don't shear off the drive mechanism and or to keep from rupturing the oil filter can or anymore psi is just a waste.

Pressure is a measure of resistance to flow. That can be frictional resistance and or a choking orifice it's cumulative but also absolute. The bearings are the end of line choking orifice. Oil pressure is then a measure of resistance to push the oil through all those clearances. Oil pressure varies from under 10 to around 50-60 normally. As measured anywhere between the oil pump and the top of the last oil gallery.

I think it works something like this.......

The in block bypass sorta looks like a check valve with 15 psi bias to open. So if the oil pump builds more than 15 psi pressure it will open as long as there is no oil in the oil galleries and the filter is providing 15 psi of resistance.

If there is oil in the oil gallery I think that exerts force back on the other side of the in block bypass and adds to the 15 psi bias. Some oil will flow through the filter unless its plugged so this check action happens quick unless the filter is plugged.

Now would the oil filter have to be near plugged once running because the bearing are in the end the largest restriction????? OR maybe the bearings would have to be bleeding more flow rate than the filter is restricting with 15 psi less pressure for it to open from the pumps standpoint.

How do you see it works?

 

[schiker]

Saying it another way. The in block bypass sorta acts like a check valve with 15 psi bias to stay closed and push oil through filter. So if the oil pump builds more than 15 psi pressure it will open as long as there is no oil restriction in the oil galleries and the filter is providing 15 psi of resistance if it were plugged or would have to be near plugged. Thick oil very dirty filter ???? how much extra resistance? Does this only happen when oil is cold and thick and hard to pass through the filter media?

IF oil flows through the in block bypass it won't flow backwards through the oil filter it will follow path of least resistance through bearings. I just don't know what happens physically. I assume oil fills all voids of the oil galleries and bearings start to provide some resistance to flow. The oil filter starts to flow oil just depends on viscosity and media cleanliness.
As oil pressure rises in oil gallery the bypass closes and "checks" ????

Does an in the filter can bypass filter have any other path for the oil to get to the oil galleries other than through the "filter" (either through media or its internal bypass). Does the oil pump flow oil and sees media restriction or bypasses media until galleries fill and oil pressure rises then it checks with 15 psi bias?

 

[WarWagon]

Simple answer: it cost GM money to put the bypass in the engine, period. Warranty claims give GM control of the bypass quality. I cut my used oil filters open...

Dips#it at parts counter giving you wrong non bypass filter is a customer goodwill problem - avoid this situation being an engine failure nightmare for you loyal customer no matter who is at fault.

Rant: Some filters are in bypass mode 100% of the time and The FRAM Group simply don't give a Fbomb. Ref pleat that wasn't crimped in one filter. Tear-O-Laters are good for 3k miles before media failure. End Rant.

So cutting filters open: where do you think I see the dirt and sludge that has settled out? Yeah, in the bottom of the filter. 4x4 or 2wd makes a difference sometimes of where the bottom is.

Where is the relief valve on filters?
A: Generally the bottom of the element.

Uh... Let's put the oil filter cold start bypass valve as close to the settled out dirt as we can. Cheap and maybe gets oil before the filter fills completely with oil. Again filter mounting makes a difference on this observation.

Bypass valves are another thing cheap Fram OCOD are famous for as well as drain back valves: simply not sealing. If it doesn't open when needed you loose the engine.

So as an OEM even though filters are on the customer there is pressure via warranty cost to do some things in the engine. Look at the e core filter design being a new standard in cheap. Look at filter failure taking an engine out from falling apart.

On 6.5's the bypass is on top of the oil filter adapters. Away from settled out in the filter or adapter...

 

[6.2 turbo]

I have mine blocked,with a tiny hole drilled in it. Without a bleed hole , sometimes after an oil change,it would loose prime,no psi untill I would loosen the filter and bleed it.

 

[WarWagon]

I have mine blocked,with a tiny hole drilled in it. Without a bleed hole , sometimes after an oil change,it would loose prime,no psi untill I would loosen the filter and bleed it.

So you suggest the bypass helps the system prime? Are you running a bypass valve equipped filter?

 

[Will L.]

@schiker the hv oil pump actually can produce 90psi according to Melling (spec peak is 94). And yes, valve stays closed until the pressure differential on the two sides of the valve is 15 psi or greater. The free flowing design of all the bearings is designed to dump 80 psi with everything at max tolerance and full flow. I have gpm spec, and can look it up tonight if folks want. thae valve will stay closed unless the filter media is plugged, be it by dirt or too thick of oil- like straight 40 in AK.

@WarWagon On the concept that no grime can settle on the bypass valve because it is in the block above the filter and adapter-- no. The crap simply settles on top of it inside the engine every time you turn it off. Yes one (probably the only) advantage of the sideways mounted oil filter is anything that can settle has a tendency to do it at in the filter media where it belongs.

@6.2 turbo Yes, please share filter name/ number incase it is a 2 valve set up that causes it. Have you tried replacing the valve? Your situation is not unique- This is one of the problems with in engine valves for other engines... I just don't know the causes as it is somewhat rare. The duramax eliminates bad internal valves by keeping it in the filter.



If a valve fails- only 2 ways to fail.

1. It stays closed. For this to get noticed it would mean the filter is plugged. I would think it could be notived on a gauge, but only by the very attentive owner who knows in situation X he should have 60psi, yet has 40, then 20, then 0, then rods on the street.
2. It opened from being in sludgeville (or someone went to visit Les and didn't swap there thick 40wt for something in the morning upon arrival). and now the valve is jammed open allowing sludge to hold it open.

breaks over~ more later.

 

[6.2 turbo]

I have ran both ,my favorite is the 1060R . On this motor the cooler is deleted ,and freeze out plugs in some of the holes in the block. I didn't decide yet on this 506 build ,but probably will use the 7202,and plug off the stock bypass.

 

[Will L.]

@6.2 turbo so the 1060R shows no bypass valve.

But you said sometimes it bleeds off-thats a bad anti drain back valve.

As for having your bypass valve blocked then a hole drilled in it- please explain.
Blocking it so it cant open forcing 100% filter or starvation, right?

Has anyone looked or done: remove the bypass completely?

I would think that would allow more flow, then with a non bypass filter- you would have your same results but more flow.

 

[6.2 turbo]

Before I figured out that it needed a bleed hole, I was just using a regular 1060. If you would leave the bypass open totally, then lots of dirty oil would get to the bearings.

 

[6.2 turbo]

I assume you know there are 2 bypass valves, the hidden one is for the cooler,and removing the freeze out plug that forces oil through there will majorly increase oil psi. But then the cooler is deleted.

 

[WarWagon]

@schiker the hv oil pump actually can produce 90psi according to Melling (spec peak is 94). And yes, valve stays closed until the pressure differential on the two sides of the valve is 15 psi or greater. The free flowing design of all the bearings is designed to dump 80 psi with everything at max tolerance and full flow. I have gpm spec, and can look it up tonight if folks want. thae valve will stay closed unless the filter media is plugged, be it by dirt or too thick of oil- like straight 40 in AK.

@WarWagon On the concept that no grime can settle on the bypass valve because it is in the block above the filter and adapter-- no. The crap simply settles on top of it inside the engine every time you turn it off. Yes one (probably the only) advantage of the sideways mounted oil filter is anything that can settle has a tendency to do it at in the filter media where it belongs.

@6.2 turbo Yes, please share filter name/ number incase it is a 2 valve set up that causes it. Have you tried replacing the valve? Your situation is not unique- This is one of the problems with in engine valves for other engines... I just don't know the causes as it is somewhat rare. The duramax eliminates bad internal valves by keeping it in the filter.



If a valve fails- only 2 ways to fail.

1. It stays closed. For this to get noticed it would mean the filter is plugged. I would think it could be notived on a gauge, but only by the very attentive owner who knows in situation X he should have 60psi, yet has 40, then 20, then 0, then rods on the street.
2. It opened from being in sludgeville (or someone went to visit Les and didn't swap there thick 40wt for something in the morning upon arrival). and now the valve is jammed open allowing sludge to hold it open.

breaks over~ more later.

Well that would be filtered grime on the clean side of the valve. Before the first time it opens. Turbulence of oil flow over the filter media to the bottom of the filter to the bypass valve can be rinsing dirt off the media. Uh, rinsed off to go through the bottom filter bypass valve.

In adaptor bypass valve leaves all the junk the filter caught in the filter.

A visit to Les is a very good example on a dirty running 6.2/6.5 as the HD use oil change interval is 2500 miles, NOT 3000, in the owners manual for a 1993. Yeah you are going to be towing a trailer so HD use. Soot can take oil out of grade from a 15w-40 to a X-50 weight. Never measured the cold "W". The military has measured it, used oil in the cold, in our reference section.

 

[WarWagon]

I assume you know there are 2 bypass valves, the hidden one is for the cooler,and removing the freeze out plug that forces oil through there will majorly increase oil psi. But then the cooler is deleted.

So is that, oil psi increase trick, what I am looking at on my 'replacement' engine? 6.2 Hummer engine...

 

[6.2 turbo]

Yea, if you don't need the cooler.

 

[WarWagon]

Yea, if you don't need the cooler.

So I need to plug this small drilled hole? I literally live in Hell so bypassing a cooler would be good for this here coldest winter on 'Hell froze over' 40-year cold winter record. Summer would fry things.

 

[Will L.]

Hmm, forgot about the oil cooler bypass valve...

 

[schiker]

I think that little hole in the cup is just to keep the oil cooler bypass valve from hydro-locking??? When it bypasses doesn't it flow through the same entry hole to the outer area of the filter media.

The cooler bypass should work nearly the same as the oil filter bypass. As in it will create a certain psi differential across the cooler. I have never heard what that differential is. There is no thermostatic control of the flow through the cooler its just simulated control with the bypass resistance differential.

What is the flow rate of the oil pump vs rpm? Any idea how much it slips?

I noticed when I let my truck drain oil for hours during an oil change it took several more seconds for it to register oil pressure Is that what you are talking about getting primed? I haven't done that ever again. I usually fill my oil filters up when changing oil.

I am gonna say "we" are never going to see a fully plugged filter but the pressure drop across the media at different flow rates, contamination, and viscosities can vary significantly.

Any guess as to the restriction of the filter vs flowrate?

 

[Will L.]

I have a couple rpm=gpm numbers at home. I will post them up (thinking I have before, but not sure). It doesn't "slip" its just a gear drive positive displacement pump, the faster it turns the more oil it pumps until the check spring reaches limit and dumps excess pressure.

As to the restriction of filter vs flow rate: that is properties of each individual filter listed in their specifications.

 

[Will L.]

Something else hit me on the what if internal valve and if you also use an in filter valve- should have no ill effect- as pointed out there is the other valve for the oil cooler...
did I miss something in that reasoning? I did just wake up an hour ago.

 

[schiker]

A long time ago I looked at some numbers on a filter's website but think it was only a standard comparison iirc clean 30 ?wt oil at 100F ? or something. I never found any real world numbers of what a dirty filter might drop or cold sooty 15w-40 oil.

I remember gasser’s oil filters bypass at lower psi iirc.