Oil filter crush temperature, with no bypass.

[oil pan 4]

There's also the risk of oil starvation if the filter clogs. It really isn't the best idea to use those filters even in warmer weather, but they are used, I'd replace them more frequently to reduce the risk of clogging.

Those no bypass wix shouldn't be getting ordered again. The ones that are in use have been in use for up to 6 months. When it cools off, almost everyone forgets those air conditioners even exist. Aside from testing there's no reason to fire those things up when it's cooler than around 80f.

 

[barryh]

This what the core of an imploded filter looks like. The mechanism is simple enough. When oil flows through the media a differential pressure occurs across the media. With cold oil and high oil flow then the differential pressure could exceed the strength of the filter and crush it, which is where the filter bypass comes in to prevent that happening.

In considering relief valves it must be born in mind that a filter bypass valve set for example to open at 5 PSI does not mean the pressure differential is limited to 5 PSI in all conditions. Bypass valves have a pressure differential across them as well and that will also be higher with cold oil. So a bypass valve will not always prevent an over pressure situation. This filter had a working bypass valve - maybe it should have been bigger.

 

[oil pan 4]

In most filters the flow is from the outer (radial) input ports to the inside threaded (outlet) port. How can you have a "crushing" event unless the differential pressure somehow occurs in a direction opposite to the outer port wrt to the central threaded output port?

One would have to have a high sucking (negative) pressure at the output (threaded) port with respect to the outer radial ports to have a crushing/implosion event.

In most lubricant system designs this system is open or partially open to the atmosphere. So how could this occur?

See the post by twX.
Looks like those guys at Cummins actually tested if an engine is capable of crushing filter media with cold oil. The answer seems to be yes, but probably no.

 

[oil pan 4]

This what the core of an imploded filter looks like. The mechanism is simple enough. When oil flows through the media a differential pressure occurs across the media. With cold oil and high oil flow then the differential pressure could exceed the strength of the filter and crush it, which is where the filter bypass comes in to prevent that happening.

In considering relief valves it must be born in mind that a filter bypass valve set for example to open at 5 PSI does not mean the pressure differential is limited to 5 PSI in all conditions. Bypass valves have a pressure differential across them as well and that will also be higher with cold oil. So a bypass valve will not always prevent an over pressure situation. This filter had a working bypass valve - maybe it should have been bigger.

View attachment 236382

May be why some hydraulic systems run both a filter head bypass and an in filter bypass.
My old big block Chevy filter to engine adaptor had 2 bypasses in it plus the filter usually had a bypass in it too.

 

[earlyre]

it's a 16 liter diesel engine.

Is it
an Abrams tank engine
caterpillar earth mover engine
stationary power generator
diesel locomotive engine or
a ship's engine?

Abrams tanks have a jet turbine engine. built to run on just about anything that burns, from Diesel, to jet fuel, to jack Daniels, or even Chanel no. 5. a true "multi-fuel" engine, as you never know what might be available out in the field.
https://en.wikipedia.org/wiki/Avco-Lycoming_AGT1500

the plant that builds the tanks (not the power packs) is local to me.
https://en.wikipedia.org/wiki/Lima_Army_Tank_Plant

 

[MolaKule]

Low-pressure hydraulic filters from Donaldson usually have a filter collapse rating of 100 psi. On a cold start, most of the engine's oil pressure could be dropped across the filter for some time. If the engine is capable of producing an oil pressure of much higher than 100 psi with cold oil, I'd say there would be risk of filter collapse if there's no bypass valve.

Here's a chart showing the pressure drop across a filter on a 11L Cummins heavy duty diesel engine after a cold start at -15°C with several 15W-40 oils. The filter bypass pressure is 85 psi. Pressure at the oil pump outlet is only 110-120 psi during this test, so most of that pressure can be dropped across the filter. If the filter in this test had no bypass valve, the filter dP likely would have exceeded 100 psi for a long time in the case of Oil B. It briefly exceeded 100 psi for all of the oils even with the bypass valve, though a lower bypass setting should prevent this.

Filter collapse isn't the only concern. Oil pressure could end up being much lower after a cold start if the filter has no bypass. This could be the case even for relatively warm starts, but for a much briefer period.

View attachment 236379

So, are you telling us the inlet (negative) pressure of an oil pump would exceed the outlet pressure? The oil pump is generally fed by a pipe from the sump.

Delta pressure means the pressure as measured across the filter; a gauge A is placed before the input filter port and another gauge B is placed after the filter. If the pressure at A is higher than at B, it means we have a positive pressure.

Where or what in the lubrication circuit would cause a negative pressure?

Where in your graph is other than a positive pressure shown?

 

[twX]

So, are you telling us the inlet (negative) pressure of an oil pump would exceed the outlet pressure? The oil pump is generally fed by a pipe from the sump.

Delta pressure means the pressure as measured across the filter; a gauge A is placed before the input filter port and another gauge B is placed after the filter. If the pressure at A is higher than at B, it means we have a positive pressure.

Where or what in the lubrication circuit would cause a negative pressure?

Where in your graph is other than a positive pressure shown?

I didn't mention any pressures being negative. In the example with Oil B, the pressure at the pump outlet is around 120 psi, the pressure at the main gallery after the filter is 20 psi, and the dP across the filter is 100 psi (though not all of this dP is across the filter element/center core).

The pressure across the center core of the filter pushes it inwards and can crush it if the dP gets too high.

 

[MolaKule]

I didn't mention any pressures being negative. In the example with Oil B, the pressure at the pump outlet is around 120 psi, the pressure at the main gallery after the filter is 20 psi, and the dP across the filter is 100 psi (though not all of this dP is across the filter element/center core).

The pressure across the center core of the filter pushes it inwards and can crush it if the dP gets too high.

So the pressure across the filter is roughly a POSITIVE pressure of say 95psi, but there is a negative pressure at the center of the filter? You'll have to explain further how you arrived at that conclusion because I know of no Black Holes in the physics of hydraulics.

Implosion implies a force generated differentially and pointed inward toward the center, whereas crushing implies a force externally applied (from the outside) and pointed inward. Stepping on a soda can crushes it.

Take an empty soda can with a special nipple and hooked up to a vacuum pump to create a vacuum inside of it. Since the pressure outside will be differentally greater than the pressure inside, the soda can will implode.

So please point out the source and direction of your forces.

 

[oil pan 4]

I didn't mention any pressures being negative. In the example with Oil B, the pressure at the pump outlet is around 120 psi, the pressure at the main gallery after the filter is 20 psi, and the dP across the filter is 100 psi (though not all of this dP is across the filter element/center core).

The pressure across the center core of the filter pushes it inwards and can crush it if the dP gets too high.

That's how I read it the first time.

 

[oil pan 4]

So the pressure across the filter is roughly a POSITIVE pressure of say 95psi, but there is a negative pressure at the center of the filter? You'll have to explain further how you arrived at that conclusion because I know of no Black Holes in the physics of hydraulics.

Implosion implies a force generated differentially and pointed inward toward the center, whereas crushing implies a force externally applied (from the outside) and pointed inward. Stepping on a soda can crushes it.

Take an empty soda can with a special nipple and hooked up to a vacuum pump to create a vacuum inside of it. Since the pressure outside will be differentally greater than the pressure inside, the soda can will implode.

So please point out the source and direction of your forces.

I don't think the filter media can tell the difference.

 

[MolaKule]

I don't think the filter media can tell the difference.

@twX That's not the point.

"So the pressure across the filter is roughly a POSITIVE pressure of say 95psi, but there is a negative pressure at the center of the filter? You'll have to explain further how you arrived at that conclusion because I know of no Black Holes in the physics of hydraulics."

Where does this mysterious negative pressure inside the oil filter come from? To implode it there has to be a pressure differential-low pressure inside, high pressure outside.

 

[MolaKule]

This what the core of an imploded filter looks like. The mechanism is simple enough. When oil flows through the media a differential pressure occurs across the media. With cold oil and high oil flow then the differential pressure could exceed the strength of the filter and crush it, which is where the filter bypass comes in to prevent that happening.

A spin-on oil filter is a component that can contain BPV's, filter media, media cage, anti-drainback valves, a ring gasket, and spring, and an outer shell of thin steel to hold the internal components, depending on the design.

What you are describing is an internal "overpressure" condition which 'collapsed' the media and or media cage, possibly due to some high pressure anomaly.

When a person speaks of a filter collapsing, one usually means the totality of the filter, that is, the thin outer shell of steel has collapsed in toward the components as if it had been run over.

Had people been more specific in their language, I doubt this thread would have come this far.

 

[oil pan 4]

@twX That's not the point.

"So the pressure across the filter is roughly a POSITIVE pressure of say 95psi, but there is a negative pressure at the center of the filter? You'll have to explain further how you arrived at that conclusion because I know of no Black Holes in the physics of hydraulics."

Where does this mysterious negative pressure inside the oil filter come from? To implode it there has to be a pressure differential-low pressure inside, high pressure outside.

You just explained it.

 

[MolaKule]

You just explained it.

No, I fully explained it in post #32 which reads,

"What you are describing is an internal "overpressure" condition which 'collapsed' the media and or media cage, possibly due to some high pressure anomaly.

When a person speaks of a filter collapsing, one usually means the totality of the filter, that is, the thin outer shell of steel has collapsed in toward the components as if it had been run over."

BTW, You were the one that made this statement: "What might the filter implosion temperature be with 15w-40 oil assuming nice fresh oil and like new filter?"

Implosion has a definitive meaning as does an oil filter.

Did you ever explain by what you meant by, "filter implosion temperature?"

Apparently you and others still don't comprehend the difference between an oil filter "collapse" and the collapse of the internal filter media inside an oil filter, but keep reading, since proper terminolgy matters.

 

[oil pan 4]

No, I fully explained it in post #32 which reads,

"What you are describing is an internal "overpressure" condition which 'collapsed' the media and or media cage, possibly due to some high pressure anomaly.

When a person speaks of a filter collapsing, one usually means the totality of the filter, that is, the thin outer shell of steel has collapsed in toward the components as if it had been run over."

BTW, You were the one that made this statement: "What might the filter implosion temperature be with 15w-40 oil assuming nice fresh oil and like new filter?"

Implosion has a definitive meaning as does an oil filter.

Did you ever explain by what you meant by, "filter implosion temperature?"

Apparently you and others still don't comprehend the difference between an oil filter "collapse" and the collapse of the internal filter media inside an oil filter, but keep reading, since proper terminolgy matters.

Tomato tomatto.

 

[MolaKule]

Tomato tomatto.

Instead of being facetious, why not learn to use proper technical terminology so you can be understood?

 

[4WD]

Tubes can have burst and collapse ratings. Load resistance …
When a filter tube collapsed - the force came from PxA generated by the media …

 

[userfriendly]

May be why some hydraulic systems run both a filter head bypass and an in filter bypass.
My old big block Chevy filter to engine adaptor had 2 bypasses in it plus the filter usually had a bypass in it too.

The filters on BBCs and SBCs such as ph13a and ph373’s don’t have a bypass. So when guys plug the bypass on the filter mount with a cap screw, they’re looking for trouble.
If you’re going to do that, use a filter from a 6.6L Duramax that has an internal bypass.
A ph13a will fit a Duramax, but should not be used because it doesn’t have a bypass. So the hot performance trick of fitting large oil filters that don’t have a bypass is not recommended on the Duramax.

 

[OVERKILL]

Not quite. The oil pump on an engine has a pressure relief. That pressure relief appears to be set about 80psi on this engine. So the filter will never see more than 80psi. If the filter develops anywhere near 80psi pressure drop across it, bad things will happen to the filter and no oil pressure to the rest of the engine is bad for it. The bypass on filters like what this healthy sized diesel engine uses appears to be in the 20 to 30psid range. If it has a bypass.

In my experience, it's more than possible to overwhelm the pressure relief, as it is not sized to be able to shunt the total volume of the pump, particularly with thick cold oil, so assuming the can is restricted to experiencing 80psi is naive. Many an SBC has been build with an HV pump and a 55psi relief spring that'll produce 80+ psi on a cold start with 15W-40, my SRT will, when it's super cold, produce pressure beyond the relief on a cold start, and that's with a 0W-40.

Your initial description, as @MolaKule noted, is confusing, because what you are describing is a collapse of the centre tube, not an implosion.

 

[userfriendly]

In my experience, it's more than possible to overwhelm the pressure relief, as it is not sized to be able to shunt the total volume of the pump, particularly with thick cold oil, so assuming the can is restricted to experiencing 80psi is naive. Many an SBC has been build with an HV pump and a 55psi relief spring that'll produce 80+ psi on a cold start with 15W-40, my SRT will, when it's super cold, produce pressure beyond the relief on a cold start, and that's with a 0W-40.

Your initial description, as @MolaKule noted, is confusing, because what you are describing is a collapse of the centre tube, not an implosion.

Yep. All the sbc’s and bbc’s I’ve built or was involved with had the HV pumps with the HP spring and pinned drives.
That’s why I don’t recommend plugging the oil filter mount bypass.
More than a few times Chevy oil filters have blown out at the drag strip often around the 60 foot mark.
A #9100 Duramax filter, say what you want, adds another layer of burst protection.
Jet boat owners with BBCs are the most notorious for this. They will start a cold engine, 30 seconds later pin it and roost people on the dock, 15 seconds later the stock harmonic balancer ring goes through the hull followed by the crankshaft.