I used a "Unibit" step drill to open up for the tube to be welded in,
you can start small, and increase a 1/16" at a time checking for
clearance. Each core may be slightly different, so you should proceed carefully
and measure more than once. Bill Schertz
KIS Cruiser # 4045
----- Original Message -----
From: David Carter [mailto:dcarter@datarecall.net]
Sent: 9/7/2004 5:24:45 PM
To: flyrotary@lancaironline.net
Subject: [FlyRotary] Re: Photos of Core tanks internals

> Ed, the dimension I'm looking for is the X (across, with "tanks" on
> each side and coolant tubes horizontal), looking down from top of
> core, with tank on each side - what is the left-right (X) dimension
> of, e.g., the top of right tank, i.e., from left side of it where
> the tank and fins meet, over to the right to the side of tank, which
> is curved as we look down on it, and measure to the "wasp
> waist"/narrower part of the tank where the coolant tubes runs left
> from.
> > I'm trying to find out how big a dia tube/fitting can be
> welded/braized onto that plate at top or bottom of "tank".
> > David
> > ----- Original Message ----- > From: "Ed Anderson" <eanderson@carolina.rr.com>
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Sent: Tuesday, September 07, 2004 5:30 PM
> Subject: [FlyRotary] Re: Photos of Core tanks internals
> > > > David, I'll check on the thickness of the end plates (I believe
> > that is
> what
> > you ask for the thickness on).  But from recollection, its a bit
> > more than 1/8".  Regarding welding, actually some of the newer
> > aluminum brazing rods would probably work better.  I finally found
> > a radiator shop who repaired radiators and they simply brazed the
> > fittings on.  But, clearly Rusty and others had better luck than I
> > did with the welding approach.
> >
> > 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 4:25 PM
> > Subject: [FlyRotary] Re: Photos of Core tanks internals
> >
> >
> > > Ed, great pictures and info!!  Thanks a lot.
> > >
> > > The larger tube on my cores is exactly 3/4" OD.  The end seems
> > > to have a 1/2" long insert in it - insert has OD of 0.678, which
> > > is the ID of the
> > 3/4"
> > > main tube.  If I cut off that 1/2" "tip" of the larger 3/4" OD
> > > tube to eliminate the "insert" (which has a smaller ID of
> > > 0.565), then I'll have
> a
> > > tube with 3/4" OD and .678 ID.
> > >
> > > On the other end cap the tubing is exactly 1/2" OD and about
> > > .460 ID -
> and
> > > has the little filter inside.
> > >
> > > I plan to run my 2 evap cores in parallel - to get greater flow
> > > than
> would
> > > be possible running them in series.
> > >     -  I will use two home-made splitter blocks, each to have a
> > >     standard
> > > radiator hose on one side (attached to engine "hot" outlet or
> > > water
> pump,
> > > respectively) and two smaller 3/4" ID hoses on the other side
> > > (to attach
> > to
> > > evap cores, inlet or outlet, respectively).
> > >
> > > After I modify each core to replace the 1/2" OD tubing with 3/4"
> > > OD, so
> > each
> > > core has a 3/4" ID inlet and a 3/4" ID outlet, these inlets and
> > > outlets
> > will
> > > have an inner area of 0.361 sq inches.
> > >     -   With two cores, I'll have a combined inlet area (and
> > >     outlet
> area)
> > of
> > > 2 times that, or .722 sq inches, to be "fed" by a single
> > > automotive
> > radiator
> > > hose via the 2 splitters.
> > >     -  Given "required area" of .722 (minimum), the "main single
> > >     hoses"
> > and
> > > any associated fittings must have at least .722 sq inch area
> > > which
> equates
> > > to an ID of 0.9588 inches (or more - use of "stock" hose and
> > > fittings
> > sizes
> > > may result in "next size bigger" than 1" ID).
> > >     -  Looking at just one website for hoses & fittings, a
> > >     fitting for
> 1"
> > ID
> > > hose had an inner bore ID of 0.84 inches.  To get a fitting bore
> > > ID of approximately 1" requires going to a 1 1/4" ID hose.
> > >
> > >     -  What is the standard sized water hose used on an RX-7?  1
> > >     1/4"? 1
> > > 1/2"?
> > > . . . . . -- I'll  use whatever fits the stock pump and a stock
> radiator,
> > > and run it to my home-made "splitter" blocks.
> > >
> > >     -  Coming out of the splitter block to my 3/4" OD "inlet"
> > >     tube on
> each
> > > core, I'll use smaller "heater hose" of 3/4" ID to slip over
> > > 3/4"OD
> tubes
> > on
> > > cores.  I'll select the tubing coming out of/going into my 2
> > > splitter
> > blocks
> > > to be identical to that 3/4" OD tubing on the cores.
> > >
> > >     -  Using water hose instead of AN fittings, where do I
> > >     look/go to
> find
> > > "bungs" on  3/4" OD tubes and 1 1/4" ID hose bungs?  I'd want to
> > > use 2
> > water
> > > hose clamps to hold hoses securely.  I haven't found a good
> > > website or source for the "bungs" to weld onto the evap cores.
> > > (I'll be putting
> > orange
> > > "fire sleeve" on all hoses - and wiring? - in the engine
> > > compartment.)
> > >
> > > In case I wanted to get even more flow than the 3/4 inch OD
> > > tubing on
> the
> > > evap cores would allow, is there room in those little flat spots
> > > on the
> > end
> > > caps to weld on a fitting or tubing with 1" OD (with approx ID
> > > of 0.964 inches or so if wall thickness is 0.036 + or -)?
> > >     -  I held my core in my lap with an "end cap" on each side,
> > >     the 13
> > > coolant tubes running horizontally left & right; I laid my ruler
> > > on the
> > core
> > > and measured 1" or maybe 1 1/8" from "inside" side of "end cap"
> > > to the narrow (wasp waist) of the segments of the end cap.
> > > . . . . - - Ed, I just reviewed your web 1998 web document on
> > > how many
> > cores
> > > you went thru before you found a good welder and how the low
> > > temp alloy
> of
> > > the cores would melt when using the higher temps required to
> > > weld on the
> > fat
> > > fittings.
> > > . . . .  ---- Looks like going to a "max size fitting" of 1" or
> > > so might
> > get
> > > the welding heat too close to the seams and not be worth the
> > > risk of
> > ruining
> > > the core.  I'm thinking I'll stick with 3/4" OD tubing on the
> > > cores.
> Just
> > > wondered if you could measure one of those "sample cores" to get
> > > the dimension "perpendicular" to the nominal 3" thickness of the
> > > end caps
> that
> > > is available for welding.
> > >
> > > David
> > >
> > > ----- Original Message ----- > > > From: "Ed Anderson" <eanderson@carolina.rr.com>
> > > To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> > > Sent: Tuesday, September 07, 2004 11:38 AM
> > > Subject: [FlyRotary] Photos of Core tanks internals
> > >
> > >
> > > > 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
> > > > >
> > > >
> > >
> > >
> >
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> > >
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> > > >
> > >
> > >
> > >
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> >
> >
> >
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> >
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