Mailing List lml@lancaironline.net Message #30521
From: <dskeele@bellsouth.net>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Re: Induction air filter
Date: Wed, 22 Jun 2005 09:49:23 -0400
To: <lml@lancaironline.net>
Hal,
  Perhaps you didn't understand my set up.. The carb air entrance is thru the front of the cowling under the prop, it seals to the cowling with the usual black cowling material rivited to the AL AIr box entrance, therefore cold air.  Carb heat comes into the top of the  box (from a heat muff around the port exhaust stack) by opening a flapper valve which closes off the cold air flow..  The Alt Air Door opens beneath the round K&N Filter and effectively bypasses it pulling unfiltered "warm" air from underneath the cylinders into the carb throat.  My Carb AIr temp sensor is up in the throat of the MS 4-5a Carburetor and I see about a 30 deg increase.  Before going Popey I always pullon full carb air heat..Hope this helps  Don Skeele   850-626-4946

From: Hal Woodruff <woodruff@swefco.com>
Date: 2005/06/20 Mon PM 09:31:12 EDT
To: "Lancair Mailing List" <lml@lancaironline.net>
Subject: [LML] Re: Induction air filter

I may not be understanding the setup with this system, but it appears that
filtered air is gained from inside the hot end of the cowling.  With this
arrangement Iıd be most concerned with the effect on the power produced when
you need power the most ­ at takeoff.   I have no idea what the temperatures
might be but it seems as though theyıd be significantly higher than ambient.
50°, 100°, 150° more?  This has got to have an adverse effect on the power
output.  Some other questions that come to mind is:  1.  what about the
possibility of detonation with really ³hot² induction air when taking off on
a hot day?  2. What is the effect on the mixture ratio when inducting hot
air ?  Wouldnıt you have an extremely rich mixture for takeoff?

I may be way off base, but the effects during takeoff of this system could
be catastrophic.  I personally would want to get some more information
before committing to this induction setup.

To fix this, possibly, the filtered air could be baffled to be in the cold
air section of the cowl.  Maybe put a chamber around the filter and duct
cold air from the cold side of the cowl.  Just thoughts...


Hal Woodruff



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