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To: flyrotary@lancaironline.net
Date: Tue, 15 May 2007 09:08:22 -0700
Subject: Re: [FlyRotary] Re: First Flight - Renesis in RV-7A
Message-ID: <20070515.090827.1820.0.alwick@juno.com>
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From: al p wick <alwick@juno.com>

I know a lot of you guys are flying with conditions similar to what Ed
describes. It gets hot during climb, but cools off during cruise. It
seems manageable. I encourage you to not tolerate such a design. This is
a root cause for crashes. You have marginal system, normally easily
managed, but suddenly other factors come into play.  We had crash last
year with marginal cooling as one of the root causes. 

One simple solution that provides extra safety margin is to just add a
spray bar in front of radiator. It just takes a tiny mist of water to
dramatically improve cooling. Strongly encourage spray bar at a minimum.
Great solution for initial testing. 

Even then, I would seek improvements that eliminate need for spray bar.
There are simple improvements out there. There are guys flying exact same
hp as you, yet they have 10 to 20% better cooling efficiency. Find out
what they are doing right.  

If you had everyone flying record their temp as they climb out from sea
level to 12k ft, you would find a couple guys with better efficiency than
the others. You'd have to record outside air temp. Coolant, oil temp at
start and end of climb. Everyone would have to climb at same rate, say 80
mph, then 90mph. Compare area of radiators. With some facts like this you
could end up with some genuine breakthroughs. Speculations do not lead to
breakthroughs.


-al wick
Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam
timing. 
Artificial intelligence in cockpit, N9032U 240+ hours from Portland,
Oregon
Glass panel design, Subaru install, Prop construct, Risk assessment info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html


On Tue, 15 May 2007 07:47:09 -0400 "Ed Anderson"
<eanderson@carolina.rr.com> writes:
> Congratulations, Dennis.  A great day for sure!  A lot of work and $$ 
> coming 
> to successful launch.  Unless you make the cooling system capacity 
> considerably greater than you need at cruise, you will always run a 
> cooling 
> deficit during climb - high power, low airspeed.  So long as it 
> doesn't 
> exceed your limits and cools off once sufficient airspeed is reach, 
> you 
> should be fine
> 
> Ed
> ----- Original Message ----- 
> From: "Dennis Haverlah" <clouduster@austin.rr.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Monday, May 14, 2007 10:23 PM
> Subject: [FlyRotary] First Flight - Renesis in RV-7A
> 
> 
> >I made my first flight this evening!!  All systems worked fine - 
> cooling 
> >was marginal in climb but we had a good inversion and the outside 
> air 
> >temperature was quite warm.  Several neighbors videoed the flight 
> and I 
> >heard several comments about how quiet the rotary plane was when we 
> played 
> >the video.  We had a 180 hp RV-7A flying chase and on the video it 
> was much 
> >louder!!  Only flew about 10 minutes but made an acceptable landing 
> 
> >considering there were about 50 people watching.  I'll post some 
> picures of 
> >the plane later tonight.
> >
> > Dennis Haverlah
> > RV-7A, Renesis, James Cowl
> > Radiators under engine
> > Catto 76 in dia- 8 in pitch
> > EC-2, Em-2, RD1-C
> >
> > --
> > Homepage:  http://www.flyrotary.com/
> > Archive and UnSub: 
> > http://mail.lancaironline.net:81/lists/flyrotary/List.html 
> 
> 
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:   
> http://mail.lancaironline.net:81/lists/flyrotary/List.html
> 
> 


-al wick
Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam
timing. 
Artificial intelligence in cockpit, N9032U 240+ hours from Portland,
Oregon
Glass panel design, Subaru install, Prop construct, Risk assessment info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html