School me on filter operation

[ZeeOSix]

Correct. That much I did know, but was curious why I saw the bigger flakes in the oil, considering there is no screen on the pump.

How big are they? ... or are you just seeing the light streaks in the oil pan like often seen on engines after the first oil change after a break-in. I can see those super small aluminum particles suspended in the oil, but they are still too small to be caught by a normal spin-on oil filter. Seen that on every new engine's first oil change that I've done.

Looking at the photo of the oil trapped in the filter, those particles look pretty big ... bigger than I'd expect. So apparently they were still small enough to become suspended in the oil and picked up by the pump, and then and caught by the media in the filter. But the "aluminum streak" phenomena I described are aluminum particles too small to be caught by the filter.

 

[ZeeOSix]

With hot oil, provided the media can flow sufficient volume that the engine remains the biggest restriction, the bypass should stay closed and drop across the media should be low.

To add ... an engine oiling system is typically about 15 times more flow restrictive than an oil filter. Example - engine oil pressure at high RPM with hot oil is 75 PSI and the filter dP is 5 PSI ... 75/5 = 15 times more pressure developed by the oiling system compared to the oil filter. Lots of people think an oil filter is so "restrictive", but they typically are not unless super loaded up.

 

[ZeeOSix]

Really fine metal particles will still make their way through the filter and bigger particles will likely sink in the sump or get held up against the pickup screen and never make it into the filter.

And possible some were still small enough to get pumped to the filter and caught by the filter as his one photo shows. Those that are too small just circulate and would be seen as "aluminum streaks" or "glitter" in the oil pan after the oil is drained out of the engine.

 

[ZeeOSix]

Correct. That much I did know, but was curious why I saw the bigger flakes in the oil, considering there is no screen on the pump.

In the oil where? Even if the oil pump had a screen, any particles small enough to be suspended in the oil are going to be pumped through the oil pump. Some of those may or may not be caught by the filter depending on their size.

 

[Propflux01]

You guys way better friends than I am. If one of my friends asked me to change their oil I would probably slap them.

Well, I have a shop, and he doesn't, so kinda one of those things.

 

[Propflux01]

How big are they? ... or are you just seeing the light streaks in the oil pan like often seen on engines after the first oil change after a break-in. I can see those super small aluminum particles suspended in the oil, but they are still too small to be caught by a normal spin-on oil filter. Seen that on every new engine's first oil change that I've done.

Looking at the photo of the oil trapped in the filter, those particles look pretty big ... bigger than I'd expect. So apparently they were still small enough to become suspended in the oil and picked up by the pump, and then and caught by the media in the filter. But the "aluminum streak" phenomena I described are aluminum particles too small to be caught by the filter.

Yes, they were a bit big I thought myself at first, so far, just checked it today after we rode, it is clear and normal.

 

[Propflux01]

In the oil where? Even if the oil pump had a screen, any particles small enough to be suspended in the oil are going to be pumped through the oil pump. Some of those may or may not be caught by the filter depending on their size.

Well, that's why I was asking, I thought the filter should have caught particles as large as those were, and that was the basis of my initial question. The fact that they are no longer there tells me things are looking ok, but gonna wait a bit, change the oil again, run it and do a UOA, at least that is the plan.

 

[ZeeOSix]

Yes, they were a bit big I thought myself at first, so far, just checked it today after we rode, it is clear and normal.

Well, that's why I was asking, I thought the filter should have caught particles as large as those were, and that was the basis of my initial question. The fact that they are no longer there tells me things are looking ok, but gonna wait a bit, change the oil again, run it and do a UOA, at least that is the plan.

Obviously, the particles inside the oil filter were caught by the filter, and anything seen in the oil drain pan where not caught by the filter. Whatever particles are suspended in the oil drain pan were too small to be caught by the filter, and whatever particles are sitting at the bottom of the oil drain pan (if there are any) were probably too large to be suspended in the sump and picked up by the oil pump. Where particles are seen basically depends on how larger they are, and if they were suspended in the oil and pumped to the filter or not.

 

[Propflux01]

If I can see them with my eyes, should they be large enough for the filter?

 

[ZeeOSix]

If I can see them with my eyes, should they be large enough for the filter?

I can see "aluminum streaks and glitter" in the oil in a drain pan as I mentioned before on engines with the first break-in oil change. Those particles stay pretty suspended and are obvioulsy too small to be caught in an oil filter if they are in the drained oil. Plus, who knows how efficienct the oil filters installed at the factory are ... could be they aren't very efficient.