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To: flyrotary@lancaironline.net
Date: Mon, 21 May 2007 07:09:31 -0700
Subject: Re: Marginal Cooling
Message-ID: <20070521.070937.2944.4.alwick@juno.com>
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From: al p wick <alwick@juno.com>

Ernest, take a look at all of your responses to my previous posts. I
think you'll find you've never agreed with anything I've ever posted. Not
the tiniest thing. I have the impression you are so keen to find fault
that there really isn't any chance for exchange. If you could throw me a
bone every once in a while, I'd at least think you were reading my posts.

I agree, the human factor is not easy to change. With businesses, I found
I could influence the human factor a bit...but not much. So I always
place my efforts in those factors that are changeable. 
I interpret your statement to be "you can't improve something if you
can't define the goal clearly". I disagree. We can still lower that temp
during climb by measuring and testing. I appreciate how that may make you
feel uneasy.

I would define my max temperature same as what an Arizona RX car sees.
The peak temp. Including water and oil. So if I can push my Arizona RX to
achieve 220 F coolant, then I would define 220F as my absolute maximum. I
think Perry did this. Not in Arizona. 

That means my engine would have same risk as that Arizona vehicle, which
statistically is likely to be low risk. Just based on assumption they
would not place any engine into service that can't handle normal
environmental variation. This all based on my background in automotive
product validation. You guys have anyone on the list familiar with
validation testing? It's pretty cool stuff. Way different than historical
methods.

Johns plane with turbo has unlimited hp. So I'd record the parameters
that cause me to peak at 220F. Let's say that's climb at 1500 fpm,
100mph, at 80F oat. Then I'd do Taguchi experiment with those items I can
change easily. The goal being to climb at that same rate, but get temp to
drop. For sure that would include all sorts of duct mods, as air flow
thru rad blew away my last test results.

regards


-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 Sun, 20 May 2007 01:05:55 -0400 Ernest Christley
<echristley@nc.rr.com> writes:
> al p wick wrote:
> > I look for root causes and systemic
> > failures. The "other" causes. 
> <snip>
> >  I'm an expert at preventing failures. Companies I managed
> > outperformed all of the competition. I have an obligation of every 
> once
> > in a while to offer a suggestion.  I expect some grief for having 
> a
> > different viewpoint....although have to admit I'm appalled at 
> this
> > eagerness to interpret suggestions in negative manner. 
> >
> >
> > -al wick
> >
> >
> > To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> > My marginal cooling was by no real means the cause of the 
> incident, but a
> > series of not-so-smart decisions by the owner/pilot.  
> >
> > In order to impress my friends, I found that pure water would 
> allow the
> > use of more power.  
> 
> Well, Al, it looks like you're not doing such a great job on this 
> one.  
> The root cause in this case is not technical.  It can't be solved 
> with 
> engineering.  It's a social problem cause by a need to engineer.  
> Unfortunately, we're not dealing with an assembly plant producing an 
> 
> endless line of the same widget.  We're dealing with a slow trickle 
> of 
> one-off designs,  each with a builder/designer that  wants to leave 
> an 
> impression by making an airplane that is somehow 'better' than the 
> others.  Each builder will define better in a different 
> way...faster, 
> lighter, cheaper, simpler, smoother, more reliable, stronger, etc.  
> They 
> want to create, and that is the root cause.  The root cause of 
> problems 
> in the activity is the activity itself.  The only way to solve it is 
> to 
> stop letting me build my own and make me buy a Cessna.
> 
> You're not getting grief for having a different opinion.  The grief 
> is 
> for not stating an opinion.  "The cooling system should have more 
> margin" is meaningless.  It may seem obvious and make you feel good 
> to 
> say it, but it is impossible to design to and belittles the 
> gentlemen 
> who ARE pouring over real numbers to pull out workable compromises 
> toward a plane that is faster, lighter, cheaper, etc. You've been 
> asked, 
> and the question bears repeating, "How do you define marginal 
> cooling?"  
> If you can't put numbers on the design criteria then nothing can be 
> 
> produced to meet them, nor is there the possibility of a test to 
> determine if it meets the criteria.
> 
> My definition for an adequate cooling system would be:  An adequate 
> 
> cooling system should be able to maintain water temperatures of a 
> heat 
> soaked engine below 210 degrees F and oil temperatures below 200 
> degrees 
> F through a full-power Vx climb to an altitude sufficient for a dead 
> 
> engine return to the airport, for any weather condition for which 
> the 
> pilot is likely to fly.
> 
> -The temps are somewhat arbitrary, but years of reading what other 
> builders have had to say makes me comfortable that these are safe.
> -Full-power Vx will be the worst case scenario used for the worst 
> case 
> takeoffs, and will differ for each airplane.
> -Turnback altitude will vary for each airplane and for each pilot.
> -I ain't climbing into a plastic solar oven when it's over 100 
> outside.  
> Somebody will just have to settle for a call that Ernest can't make 
> it.  
> So there's no point in worrying if the cooling system can handle 
> that 
> sort of torture when I can't.
> 
> What is your definition of marginal?
> 
> --
> Homepage:  http://www.flyrotary.com/
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> 
> 


-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