Mailing List lml@lancaironline.net Message #30569
From: Hal Woodruff <woodruff@swefco.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Induction air filter
Date: Thu, 23 Jun 2005 14:53:39 -0400
To: <lml@lancaironline.net>
Dan,

That's not fair to say that "if its not invented here" (NIH syndrome) then
an idea is suspect and should be dragged through the dirt.  I agree that the
idea is an esoteric solution to a problem that plagues most builders, that
is, "how to stuff ram air and a filter into the same small space."  But to
imply that my, or anyone else's motive is to defile an idea because "we"
didn't think of it is, well, way off base.  My purpose in bringing up the
discussion was purely to have those that are contemplating such a system to
look at all the ramifications.  There are some major problems with drawing
hot air into the engine for high power operations.  I can think of two:
reduced power output, and the possibility of detonation. There may be more.
These problems are more consequential than "pulling" on the carb heat.  To
imply that you've run your engine, as we all have, with carb heat on and the
engine did not catastrophically fail, is poor evidence of the potential long
term effects of detonation.  Would an engine using hot air for induction
experience detonation?  I don't know but I think its worth looking at.
Could this scenario happen?  Sure, suppose one takes off on that hot day,
forgets to switch to ram air after take off, and climbs to 18000 feet at
full power.  Will the engine survive such an encounter? Probably.  Is it
optimal? No - better would be inducting cold air.

Don Skeele appropriately pointed out that indeed the air filter in his setup
is situated in a baffled cold section of cowling.  And so, there is not a
problem with his installation.  I apologize for creating such a stir by
misreading the pictures.  I made a bad assumption (and thus, I've made an
ass of myself).  I assumed that the setup was in the hot side of the
cowling.  It wasn't obvious from the pictures that accompanied the
discussion that the filtered operation was getting cold air. On the other
hand, if I made that mistaken assumption, then, I suppose others could also
and consequently install a less than optimal and potentially dangerous
induction system because they thought it had been done before with no
consequence.

I, too, say "hang in there" to John and that this indeed is one of those
elegant solutions to a problem.  I also want to make sure that in our zeal
to achieve that extra few knots, or that extra 1/2 inch of manifold
pressure, that our modifications/installations are based on sound
engineering principles and that we've thought through all the ways/modes in
which the installation will operate.  One of the ways this takes place is by
submitting our ideas to this forum - for the exaltations, and the criticism.
Wouldn't it be a shame if a deficiency wasn't pointed out for fear of being
accused of jealousy because of the so-called NIH syndrome, and someone's
"elegant solution" resulted in a new statistic.

We're here to help each other.  Let's keep it an open forum by promoting the
free exchange of ideas without accusing the motives of the contributor.


Hal Woodruff
(I'll be away from my computer Fri-Sun ready to take the heat starting next
Mon - flame-suit on)
>
> Hang in there, John.
>
> A "can of worms" is the worng definition - this is merely the usual spirited
> debate often kicked off on this forum by what is a neat idea, but carries
> the NIH (Not Invented Here) syndrome.

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