Steve
Ive been deeply involved in filtration engineering for almost 30 years
..... this test is HOGWASH and marketing HYPE.
It purports unsupported claims vis a vis NO mention of the nature of
the test contaminent (usually AC FINE test dust ... an industry
standard). NO mention is made of the face velocity nor control of the
velocity of air flow, etc. etc.

The fact of the matter is that ALL these 'manufacturers' DO NOT make
the filter media (resinated technical paper) ... and there are only 3
technical paper mills supplying the WHOLE of this segement of the
automotive filter market .... so the question therefore is if
essentially 3 paper mills are make all the paper, then how come the
differences.
K&N is known poor technology, but the difference of the others ....
HYPE and marketing.



In article , Steven
Shelikoff wrote:

http://home.usadatanet.net/%7Ejbploc...011/SPICER.htm

Rich Hampel wrote:
Steve
Ive been deeply involved in filtration engineering for almost 30 years
.... this test is HOGWASH and marketing HYPE.
It purports unsupported claims vis a vis NO mention of the nature of
the test contaminent (usually AC FINE test dust ... an industry
standard). NO mention is made of the face velocity nor control of the
velocity of air flow, etc. etc.

The fact of the matter is that ALL these 'manufacturers' DO NOT make
the filter media (resinated technical paper) ... and there are only 3
technical paper mills supplying the WHOLE of this segement of the
automotive filter market .... so the question therefore is if
essentially 3 paper mills are make all the paper, then how come the
differences.
K&N is known poor technology, but the difference of the others ....
HYPE and marketing.


Thanks for lending your expertise. It's good to hear from someone who's
actually in the field.

The 'trickery' in such marketing hype is pricipally due the the larger
surface area of the 'target' filter.
There's a moral he buy the LARGEST filter that will fit as the
velocity THROUGH the filter media will be at its slowest and the
particles will have sufficient 'dwell time' to adsorb and be captured
by the filter media. Air filtration doesnt have 'pores' the size of
the particles you want to capture ... in actuality (and more
importantly for the smaller particles) its the energy of the particles
(brownian motion amplitude) allowing capture of very small particulate
with relative large 'pores'. Its the 'dwell time' inside the filter
media that does the 'filtration'. So if you used a container of
compressed pubic hair it would filter quite well if you keep the
velocity of the gas very slow .... but I dont know where you'd find
that much pubic hair.
Gas/air filters are rated on 'most penetrating particle' vs. velocity
.... when you see that statement omitted you now that someoe is trying
'to sell you a bridge'. Especially when the data refers back to an ISO
standard which typicallly has more to do with political exclusion of
'foreign' manufacturers from the EU marketplace than simply 'whats the
best to use'.

The most damaging particle acknowledged by the automotive industry is
about 20 micrometers ... a very large particle and a particle that
settles very quickly by simple gravity.

Just remember to 'size' your air filter at: AS LARGE A SURFACE AREA
THAT YOU CAN AFFORD. Simple!



In article .com,
basskisser wrote:

Rich Hampel wrote:
Steve
Ive been deeply involved in filtration engineering for almost 30 years
.... this test is HOGWASH and marketing HYPE.
It purports unsupported claims vis a vis NO mention of the nature of
the test contaminent (usually AC FINE test dust ... an industry
standard). NO mention is made of the face velocity nor control of the
velocity of air flow, etc. etc.

The fact of the matter is that ALL these 'manufacturers' DO NOT make
the filter media (resinated technical paper) ... and there are only 3
technical paper mills supplying the WHOLE of this segement of the
automotive filter market .... so the question therefore is if
essentially 3 paper mills are make all the paper, then how come the
differences.
K&N is known poor technology, but the difference of the others ....
HYPE and marketing.


Thanks for lending your expertise. It's good to hear from someone who's
actually in the field.

Speaking of filters...

...boat I just bought has a Perkins 4-108. I was surprised to see it has
no air filter, only what looks like a flame arrestor. IOW, a metal
screen under a cap. I can't believe this is how it should be, altho the
manual shows this is the part. I'd like to put a real filter on the
intake. Suggestions on where to find an assembly that would fit and be
appropriate?

On Tue, 9 May 2006 23:56:57 +0000 (UTC), wrote:

.boat I just bought has a Perkins 4-108. I was surprised to see it has
no air filter, only what looks like a flame arrestor. IOW, a metal
screen under a cap.

That is typical on a marine diesel. After all, where is the dust and
dirty air going to come from unless you boat on the Red Sea?

That is typical on a marine diesel.

Not the previous two I have owned.

Many things can supply dust, even on a boat. lord knows I have enough on
my boats. Among other things the engine is old and the paint is flaking.
Those particles could go airborne.