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Ed,
What is amazing to me is that there are only three small holes in each
cross-tube. Its hard to believe that these small holes will pass
enough coolant to cool a 13B @ WOT.
Mark S.
At 12:38 PM 9/7/2004 -0400, you wrote:
Well, David, I just went down
to the shop through the pouring remnants of
Frances and cut open each side tank of a core I had taken from the
junkyard
years ago.
The photos are attached and speak for themselves - no dividers or
other
impediments to coolant flow in the tanks - pretty clean channel from top
to
bottom. Each "row" has 5 approx 1/8" (perhaps
slightly larger) dia holes
that conduct the water through the core to the opposite side tank.
So 14
rows * 5 * area of 1/8-3/16" dia hole would give a cross flow
channel area
of around 0.86 sq inches to 1.93 sq inches - probably toward the
larger
figure.
So as Bill suggested they may have redesigned the heat exchangers to take
a
different approach to recondensing the refrigerant calling for the
divider
plate. Given the relatively small cross channels, it is my opinion
that a
serpentine cooler is probably offering considerably more resistance to
flow.
Some of the radiator shop webpages give an estimate of the increase in
flow
resistance of a Serpentine core over the straight through - as best I
recall
it was something like 4 times as best I recall.
So, its clear that not all GM evaporator cores are created the same
way.
This one was from the an late 80s early 90s Cadillac. I looked all
over for
some identifying model number but could not find anything. I do
recall it
had a yellow sticker with a black C on it when I yanked it.
In any case, it looks like we can not simply order just any GM cooler
core.
I suspect that when they switched over to the more environmental
friendly
refrigerant then there could have been some redesign of the core,
but just
speculation on my part.
Here's the photos
Ed.
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
----- Original Message -----
From: "David Carter" <dcarter@datarecall.net>
To: "Rotary motors in aircraft"
<flyrotary@lancaironline.net>
Sent: Tuesday, September 07, 2004 11:55 AM
Subject: [FlyRotary] Re: Water pump problem
> Thanks, Ed.
>
> I wonder Steve Brooks's core with a "plate" is different
from the
> GM/Harrison cores that I have (Chev'y Caprice).
> - When I probed my core last night and found
no plates in the end cap
> with the larger of the two welded tubes, I DIDN'T check the other
side -
> those smaller 1/2" OD tubes turn 90 degrees and run about a
foot, so I
never
> probed that side. That is the side that has the little
"filter" and/or
> "expansion jet" thing sitting about an inch down
inside. Perhaps there's
a
> plate on that side that matches what has been discussed
recently.
>
> If Steve's core is a typical GM/Harrison core, then I'd like to
understand
> more about which end "the plate" is in and tell us more
about "the tube
that
> was removed". I've not yet cut into any of my cores to
mod the fittings,
so
> am ignorant of the insides.
>
> David
>
> ----- Original Message -----
> From: "Ed Anderson"
<eanderson@carolina.rr.com>
> To: "Rotary motors in aircraft"
<flyrotary@lancaironline.net>
> Sent: Tuesday, September 07, 2004 6:54 AM
> Subject: [FlyRotary] Re: Water pump problem
>
>
> > Hey, David, not to worry. We have all hit the
"Send" button on an e
mail
> or
> > two and later wondered why we did. {:>)
> >
> > Ed
> >
> > Ed Anderson
> > RV-6A N494BW Rotary Powered
> > Matthews, NC
>
>
>
> >> Homepage:
http://www.flyrotary.com/
> >> Archive:
http://lancaironline.net/lists/flyrotary/List.html
>
>> Homepage:
http://www.flyrotary.com/
>> Archive:
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