OK--I believe in the centrifugal oil filter now!!

brewsky · Post by **brewsky** » Thu Oct 11, 2012 7:16 am

WOW!............a synthetic DIRT thread!!!!

Jensen, what kind of dirt would you expect NOT to be filtered by the centrifugal filter?

That which is equal to or less than the SG of the oil? What kind would that be?

I would think pieces of glass would be separated.

Some non-destructive testing at the local high school chemistry lab should prove/disprove that.

cknight · Post by **cknight** » Thu Oct 11, 2012 8:01 am

I believe that synthetic dirt was pioneered by the same folks that perfected the appendix transplant... Chase

jensey · Post by **jensey** » Thu Oct 11, 2012 8:57 am

Brewsky,

Try it in your engine, and see if you're right.
after all, it the best riding laboratory you've got.
And it ain't a model, but the real thing, really, you should try it.

What can happen ? The spinner filter will filter it out ! So I would say it's a non-destructive test.

The fact that you mention it as possible destructive means you're not sure, why ? What can happen ?

The gears will grain the glass particle a bit until these are small enough to go through the pump filter, and after that it will be filtered out by the spinner filter. So no harm done, agree ?

Jensen

brewsky · Post by **brewsky** » Thu Oct 11, 2012 9:35 am

jensey wrote:Brewsky,

Try it in your engine, and see if you're right.
after all, it the best riding laboratory you've got.
And it ain't a model, but the real thing, really, you should try it.

What can happen ? The spinner filter will filter it out ! So I would say it's a non-destructive test.

The fact that you mention it as possible destructive means you're not sure, why ? What can happen ?

The gears will grain the glass particle a bit until these are small enough to go through the pump filter, and after that it will be filtered out by the spinner filter. So no harm done, agree ?

Jensen

You seem to be avoiding the question.........what type of dirt produced by the engine is NOT filtered/separated by the spinner?

jensey · Post by **jensey** » Thu Oct 11, 2012 10:26 am

Maybe you avoid reading the word glass particles for instance ?

But an answer to your question, aluminium which has a SG of 2,7 (close to glass, SG of 2,5).
Steel however is filtered out much better (but not 100%) with a SG of 7.8 or bronz, with a SG of 7.8.

(and all the other debris in the engine cases)

btw, the title says it all : OK--I believe in the centrifugal oil filter now!!

Snakeoil · Post by **Snakeoil** » Thu Oct 11, 2012 3:14 pm

There was a discussion here about the ability of centrifugal or inertial separators working with oils that hold dirt in suspension better than oils of the past. At least I think it was here.

One of the concerns with Brit bike owners that use the crank bore as the filter, aka "sludge trap" is that the detergents tend to keep the contaminants from adhering to the "filter" walls and maintain them in the oil and hence run them thru the engine. This is why the general consensus is the best thing you can do for any engine is install an automotive type oil filter.

I tend to agree with that. Jensen seems to think I'm a big proponent of inertial separation over real filtration and that is not the case. If I had my druthers, every engine I have would have a cartridge filter on it. And that just may be one of my retirement projects since I'm going to become a burden on society at the end of November.

regards,
Rob

brewsky · Post by **brewsky** » Fri Oct 12, 2012 6:15 am

jensey wrote:Maybe you avoid reading the word glass particles for instance ?

But an answer to your question, aluminium which has a SG of 2,7 (close to glass, SG of 2,5).
Steel however is filtered out much better (but not 100%) with a SG of 7.8 or bronz, with a SG of 7.8.

(and all the other debris in the engine cases)

btw, the title says it all : OK--I believe in the centrifugal oil filter now!!

Jensen,

You stated that the centrifugal filter would work only if the SG of the dirt was not equal to that of the OIL.....right?

If that is true, and I believe it is, then all of the above would be filtered. Anything with an SG less than oil would remain in the middle, instead of on the outside wall.

The only difference the SG's of the dirt particles would matter, relative to each other, is what layer they end up in against the filter wall.

Again, here was my question........."what type of dirt produced by the engine is NOT filtered/separated by the spinner? "

I have no opinion which is "better", but I remain ready to be convinced.

Rob's comment about the newer detergents is interesting, and I've not heard that before.

I have also heard that some of the new spinners, if not applied correctly, can actually remove some beneficial oil additives.