Message-ID: <000601c3b0f6$8b81f860$1702a8c0@WorkGroup>
From: "Ed Anderson" <eanderson@carolina.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-2761148@logan.com>
Subject: Re: [FlyRotary] Re: radiator
Date: Sat, 22 Nov 2003 07:45:44 -0500
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 PM
Subject: [FlyRotary] Re: radiator


> I'm not joint this "thread" on "theoretical calculations" becasue I need
> more info on how I'll set up my cooling system - I already know what I'm
> going to do - use two GM a/c cores like the other successful operators of
> rotary powered RV's.  Just mount them "better" I hope - see earlier post
> (today?) re "cowl with no holes so I can cut and shape my own holes where
I
> want them."
>
>   SNIP

> Now, what I'd really enjou is peer review/comments on my design stuff, not
> hot day calculations.
>
> David Carter
>
> ----- Original Message -----


Well, why didn't you say so, David {:>)

    As you should know this group is willing to review or comment on just
about anything.

Seriously,  I agree that an theoretical approach can be useful in
determining what the significant factors are in a situation - I would never
have thought that port timing would have the effect it has on the DIE before
doing the analysis.  Now that I know, I can do a better job of designing my
next manifold.  However, I've learned long ago that models of the real world
(including math models) are just that and seldom reflect all the intricacies
or subtleties of the real world.  If they do, they are frequently too
complicated for easy use or else difficult/ impossible to get the input data
needed.  If they are too simply, then of course, they may not reflect the
real world close enough to be really useful.

To add to the confusion, I think we not infrequently draw the incorrect
conclusion about why something does or does not work well.  So many
variables - any of which could be the cause.
But, I think if we knew all the answers, then it would take away some of the
challenge that makes this interesting.

I think its great that some folks are always willing to try something
different or challenge old assumptions - that's the way we make progress.
For years, I was convinced that Ford evaporator cores would be unsuitable
for radiators based on a thoughtful article in "CONTACT!:" magazine where
the author cut apart both the Ford and GM types and showed that the cross
channels in the Ford were quite a bit smaller than the GM cross channels.
The conclusion was that the Ford cores would offer much more resistance to
water flow.
However, from some testing recently done by one of the list members, it
turns out he found the Ford cores flow somewhat better than the GM cores.
So was the original assumption flawed or did perhaps Ford change core in the
intervening years?  Don't know, but just an example of a "fact" that did not
stand up to testing.

So hang in there and keep designing your project!

Best Regards

Ed Anderson