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Reply-To: "David Carter" <dcarter@datarecall.net>
From: "David Carter" <dcarter@datarecall.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
References: <list-395977@logan.com>
Subject: Re: [FlyRotary] Re: Water pump problem
Date: Tue, 7 Sep 2004 01:09:11 -0500
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Disregard my last two e-mails - hit "Delete" on them.

I apologize for not looking at my cores before I wrote the last 2 e-mails.
All I said was an exercise in massaging bad data from a bad memory.

I got up from bed after sending those 2 e-mails and went out to the shop and
looked for "welds" for the "blocking plates".  No such thing.  The core sat
in the car with two tubes sticking up, but the fiinned tubes ran
horizontally, between two "end caps" that were vertical, so there was a tube
in each end cap - 1 for inlet, 1 for outlet.  You guys all knew that - I had
just forgotten or failed to "understand" what I "saw".

Just to be sure, I ran a piece of safety wire down the shorter, bigger dia
tube and it went all the way to the bottom of the "end cap" with no blocking
plates.  So, it is NOT serpentine.

Wish there was a way to delete those 2 e-mails from the server so you
wouldn't waste time reading them and wondering what kind of weird evap core
I was talking about.

David

----- Original Message ----- 
From: "David Carter" <dcarter@datarecall.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, September 06, 2004 10:43 PM
Subject: [FlyRotary] Re: Water pump problem


> I just checked all my saved e-mails on A/C cores - and I find NONE where
> someone reported he had cut one open and thoroughly examined the flow path
> and details related thereto.  This recent info indicates to me that the
> plates "2 inches down from one pipe" must be to cause "serpentine flow",
> i.e., block off maybe bottom 2/3 so liquid flows across one way only in
the
> top third, then another blocking plate 2/3 down on the other side forces
the
> liquid to reverse course and go back across in the opposite direction,
> coming out UNDER the first blocking plate on that side, the being forced
> down to reverse course through the bottom third.  Then, when it comes out
of
> bottom third of tubes on far side (from original inlet), it has to get
back
> to the top "exit tube" on the far side - that must be what the "inside
tube"
> is for - to go thru the blocking plate on that far side.  Does this make
> sense?
>
> Now, having said that, I just found and reviewed a note I made last 17 Nov
> 03.  I called the guy at www.frigidair.net and asked specifically about
> "serpenine" or not? on the Caprice evap cores he makes and sells from the
> web site.  The website doc even has a column, which is blank, labeled
> "Serpentine".  That is what prompted my call to him, to confirm if there
is,
> or is not, serpentine flow.  He said they were just like a radiator - all
> the stuff goes in on one side and flows across all the tubes in one
> direction to the other side and out.
>     -  Now, he is an "aftermarket"mfr of "OEM" cores.  Thus, the cores
> "should" be same as OEM, the stuff we are taking out of cars.
>     -  Base on this latest report that there is a "blocking plate", I no
> longer believe the guy's info.  Either he doesn't know how his stuff is
made
> or he is not making it the way GM/Harrison made them.
>
> So, please tell us again, and more, about "removing the tube":  Wasn't it
> welded to a "blocking plate" (so no leaks around it)?  Or was it a fairly
> close or tight fit thru a hole in the "blocking plate" to make leaks
> inconsequential?
>
> In any case, based on what I think has been reported and what I understand
> about a 3 layer "over, back, and over again to the other side" serpentine
> internal construction, here's why I believe you are cooling only on the
top
> third of the core:
>     -  The coolant comes in on the side with blocking plate 1/3 of way
down
> and there was never any tube in that side - stuff can't get past that
plate
> and is forced "over" thru top 1/3 of tubes.
>     -  Once it gets to the other side, with the tube removed, there is a
> hole directly "out" the top of the core, which is where the fluid goes.
At
> the same time, if any tries to go down and "back across" to original side,
> it really won't flow, as it is also going down through the hole left in
the
> "2/3 down blocking plate" when the tube was removed from hole in that
plate,
> and so fluid tries to flow "back through both the "middle third" and, if
> goes down thru hole in blocking plate, also tries to go "back" thru bottom
> third, so going across both middle and bottom thirds - and nowhere to go -
> just a stagnant flow area with no outlet.
>     -  So, all the flow from top 1/3 goes out the top and "warm stuff"
just
> sits in the bottom 2/3 of tubes.
>
> Sound like what you are seeing/feeling?  If so, putting the "tube on
> 2nd/exit side" back thru the "2/3 down blocking plate" should restore
normal
> serpentine flow, with all fluid come OUT of the TUBE you just put back in,
> which has to either be sticking out of top of that "end cap" or be welded
to
> the top, so nothing from top 1/3 can escape without going thru the entire
"3
> pass serpentine path".
>
> David
>
> ----- Original Message ----- 
> From: "Russell Duffy" <13brv3@bellsouth.net>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Monday, September 06, 2004 8:35 PM
> Subject: [FlyRotary] Re: Water pump problem
>
>
> No.  It had one tube in each of the tanks.  Both in the top.   One tank is
> blocked off by a plate about 2" down from the top.  The other tank
> originally had a tube in it internally that extended to within an inch or
so
> of the bottom.
>
> Does that make sense ?
>
>
> I must be misunderstanding something, because I don't see how the original
> configuration could have been using the whole core in the car.  Let's
forget
> that for now though.
>
> You should now have a tube in each tank.  Both tanks should be open from
top
> to bottom, meaning that you'd have to have drilled a hole through the
> blocking plate that was installed in the tank.  If you didn't open up the
> blocking plate, you're only using the top two inches of the core, which
> would explain why that's all that's getting hot.
>
> To rephrase this another way, one tube should come into the top of one
tank.
> The liquid running into the tank should be able to go through every one of
> the flat tubes that join the tank.  The liquid should be able to come out
> every one of those flat tubes in the other tank, and go up and out through
> the outlet tube.  Is that what you have now?
>
> If the above wasn't clear, I'm afraid we're going to have to resort to
> drawings :-)
>
> Cheers,
> Rusty (glad the South FL boys survived)
>
>
>
>
>
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