Slight boost pressure at all times

[Tom Cloud]

>> snip .....
>> 
>> To digress slightly -- a 1000 cfm Rotron cooling fan,
>> what benefits could one expect from putting something
>> like that in the intake flow ???  It draws little juice
>> and would insure a _slight_ positive pressure flow
>> under all conditions -- and esp at low vehicle speeds.
>> 
>> Just a thought I've been playing with.  Seems it
>> might make some slight but noticeable improvement
>> on the normally aspirated engine ???


>This sounds similiar to a device that Smokey Yunich (sp?) used in an
>article about how he got 40% increase in hp & 40-50mpg from ANY engine
>(thats right - a retro-fit) just by using a similiar trick in the intake
>stream.  It was a three-stage intake setup used to prepare (by heating &
>homogenizing) the mixture for a more optimal combustion.  The carb was
>relocated over by the fender and the air/fuel mixture was first heated
>using the coolant then by exhaust gas and finally mixed(??) using a
>turbo-like device that he called a homogenizer.  It was like a turbo
>(being exhaust gas driven) but didn't produce much pressure.  Instead,
>he said that it acted as a 'one-way check valve' of sorts.  The engine
>seemed to be aspirating itself due to a/f mixture expanding against the
>engine on one side and the 'check valve' on the other while in the final
>stage.  
>
>This is just the kind of effect that you mention - slight boost at all
>times.  Care to elaborate on the 1000cfm fan thing?  How much juice does
>it requre?

A Rotron (actually Comair/Rotron) Caravel fan is rated at
550 cfm at 0" and 400 cfm at 1", consumes 60 watts (5A at
12 VDC) and costs about $60.  It's 10 " in diameter and
3.5" thick.  It runs off line joltage, so would require
an DC-2-AC converter.  All-in-all, probably a large investment
for what will probably return a very small improvement -- esp.
if'n you don't have all the stuff .... but I do.  So, I'm
intrigued by the Smokey story.  Seems the only improvement the
small fan could be expected to provide would be low-end
throttle response -- esp since there's virtually no real
"boost" (1" of H2O).

back to the fans.  I have an old Rotron rated at 1000 cfm (think
it was called a "Centaur" or such).  ebm/Papst make both
axial and centrifugal fans up to 2040 cfm.  Their 1060 cfm
axial requires 190 watts; their 710 cfm centrifugal, 200 watts.
Actually, the stock heater motor in a car is probably 400 cfm
full out.

I didn't ask this question really expecting to find any
amazing benefits .... I've only played this thing in my
twisted cranial cavity and can see no real advantage, but
it's intriguing nonetheless.  I did want to see if anyone
had toyed with the idea and/or actually done any tests
with it.

Tom Cloud <cloud at peaches.ph.utexas.edu>