Re: Bipass Oil Filtration Systems

[alex.fadeev@xxxxxxxxxxx]

"John Bolhuis" <bolhuijo@domain.elided> wrote:
> On Mon, 20 Jan 2003 alex.fadeev@domain.elided wrote:
> 
> > > The logic is that the by-pass filter removes particles smaller
> > > than 1 micron, on the theory that particles in the 5-20 micron
> > > range are responsible for 60% of all engine wear.  Full flow
> > > filters only filter down to about 25 microns.
> > 
> > John,
> > Oil bypass is a spring loaded devise in the oil filter that opens
> > up when the filter gets clogged. The idea is that it's better to 
> > oil the engine with unfiltered lube than not at all.
> > Are suggesting filtering that bypass channel?
> > Or are you saying that all stock filters suck and a finer particle 
> > filters are the only thing that will save the engines from impending
> > demise?
> 
>  You are correct about the bypass mechanism in a standard full-flow
> filter setup.  We're not talking about that at all.  All stock filters
> do not suck.  Finer filtration is better though.
>  My by-pass filter hooks into the port where the oil pressure sender
> lives.  It steals a little oil from there, routes it to a large
> external filter with an efficiency in the 1 micron range, and drops it
> back into the engine through a port in the valve cover.  The standard
> filter filters ALL the oil, and the by-pass filter filters a little at
> a time.

Ahhh, now I get it.

> > >  This is great if you drive a lot of miles, want to maintain 
> > > the highest standards of cleanliness, and like the long drain 
> > > intervals. Some of these guys are going 2 or 300k miles with 
> > > only filter changes.
> >
> > That's crazy.
> > Sorry if that is too strong a language for some of the readers.
> > Any oil, including synthetics, breaks down in the 3-25K range.
> > Engine operating conditions have a lot to do with it, so milage
> > alone is not a good indicator of oil degradation.
> 
>  High quality synthetic, coupled with the by-pass filtration system 
> is capable of going much longer.  Part of the strategy is replacing
> both filters every 6 months or 12.5k miles. 

OK, that takes care of the filter degradation problem.

> That adds a couple quarts of fresh oil to the system. 

That's not much.
This is the same problem faced by people with high oil consumption ratios. 
You may be adding a quart of new oil every week, but the stuff that has 
not burned off (been removed with filter changes) may be turning into 
sludge at the base of the oil pan. 

> The filters keep the oil squeaky clean particulate wise, 

What about chemical breakdown from exposure to heat, blow buys, 
condensation and gasoline that inevitably finds its way into and dilutes 
the oil?

> and the periodic addition of oil keeps the additive package adequate. 

Not likely.
Adding 1-2 quarts every 10K miles only represents 10-20% of the oil in the 
engine. 
That's 10-20% of the intended additive package concentration. 

> It really does work, and oil analysis proves it.

How so?
Where is the data certifying proper test conditions and outcome?

> That being said, it isn't for everyone, but long-haul truckers
> (who have ~11 gallon oil sumps!) and other high mileage users 
> appreciate such a system for the low frequency of maintenance.

I can not comment - no first hand experience.
Interesting idea. I can see how truckers would be interested in something 
like this. 
If you don't drain oil, you may never get the sludge that settles down on 
the bottom of the oil pan. But I suspect there is a way to overcome that 
problem (secondary filter pickup from the bottom of the oil pan).
The only two other concerns are practicality and oil degradation. 

alex f

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