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Ed,
I was wondering if there might be holes on the outer edges that I
couldn't see. So there are 2/3 more holes than can be seen in the
pictures. Obviously, there's enough flow to do the job. Also,
I noticed on the second picture there appears to be a hole or two that
appear to be plugged. I would surely want to be certain that my
system is thoroughly flushed when using a/c cores (especially used ones)
so as to prevent blockage of these small holes.
Mark S.
At 01:37 PM 9/7/2004 -0400, you wrote:
Actually,
Mark, there are 5 holes , three toward the center that are easy to see in
the photos and two at the extreme sides of the tanks. Yes, at first
glance, you would think no-way it would cool - heck you wouldn't even
flow much coolant through it. But a 1" dia hose only has 0.785
inches of area.
Surprisingly the total area
of these small holes adds up to between 0.83 and 1.93 sq inches
(holes appear to be between 1/8 - 3/16" in dia) - more than you
would think. So certainly a lot of loss with so many small holes,
but if the 1.93 sq inch area is close to their total area then they are
probably as effective at flowing coolant as a 1" hose with 0.785 sq
inches.
This is one I successfully flew
with before the stress of the heavy AN-16 fittings hanging off the 90 deg
fitting cause it to spring a small leak.
Ed
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
- ----- Original Message -----
- From: Mark Steitle
- To: Rotary motors in
aircraft
- Sent: Tuesday, September 07, 2004 1:06 PM
- Subject: [FlyRotary] Re: Photos of Core tanks internals
- 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:
http://lancaironline.net/lists/flyrotary/List.html
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