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Message-ID: <2e24f88d0705290830q1c2d2447ja8cff09638a79e1d@mail.gmail.com>
Date: Tue, 29 May 2007 09:30:39 -0600
From: "Hans Conser" <hansconser@gmail.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] James Cowl - RV-7a - Renesis - Cooling
In-Reply-To: <list-2070151@logan.com>
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References: <list-2070151@logan.com>

Denis, before you going adding vanes, I would measure the Delta P with
a manometer.
There are a few questions I have after looking at your pictures.

1)  It is unclear how clear the space behind the radiator is, can you
show us a picture of that area?

2)  The only line I see going to the radiator looks to be the same
diameter as the line going to the oil cooler.  Is this a burp line or
the actual radiator line?  If so it looks very small!

3)  Do you have a sealing mechanism between the cowl and the coolers?

Hans

On 5/27/07, Dennis Haverlah <clouduster@austin.rr.com> wrote:
> I had very marginal cooling on my first and second flight - RV 7A, James
> cowl, Griffin Scirocco aluminum double pass water radiator with a Mazda
> 1989? RX-7 oil cooler.  Water radiator fin size - 22LX13WX2.5T inches.
> Oil - 19LX4.5WX 2T  inches.  The radiators are mounted side-by-side
> under the engine and are at about 25 - 30 degree to the inlet air flow.
> (The air must turn 60-65 deg to flow through the radiators)   See photos
> 1 and 2.  After my first 2 flights, I constructed a divider/duct to
> provide a duct for the engine combustion air to make the sharp turn 90
> deg. up after the inlet to get to the filter.  The bottom of this duct
> was also supposed to provide a duct wall for the air going to the
> radiators.  See photo 3.  Two flights demonstrated this really hurt -
> not helped  - my cooling.  Now I can barely take off and fly the pattern
> before getting up to 210 - 215 on oil and water.  The divider duct took
> out about 8-10 sq. in. of inlet area but removed the engine combustion
> air requirement form the remaining inlet air going in the larger inlet.
>
> My inlet is about 50 sq. in. and the outlet is about 67 sq. in.  This
> cowl was used successfully on the Power Sport a/c so I believe the inlet
> and outlet are at least big enough for 160 + hp.  When I first posted
> pictures of the radiator installation someone suggested I may need
> turning vanes to improve flow to the radiators.  I am now ready to try
> the turning vanes below the radiators.
>
> Does anyone have info. I can use to design the turning vanes?  The K&W
> document on page 273 mentions guide vanes but does not go into detail.
> I am thinking of 2 inch wide vanes long enough to go from the left to
> right side of the radiators and spaced 4 inches apart  with the top of
> the vanes about 3/4 inch below the radiator  fins.
> Comments or -- Any other ideas?
>
> Dennis H.
>
>
>
>
> --
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