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Rino,
Were the inlets and outlets of the oil cooler oriented so that if air
got into the cooler it could get out? If you had a single pass oil cooler
and the in/out were both on the bottom, you could trap air in the cooler and
the oil would flow thru it fine, but no cooling would happen. Likely the
same if the outlet was on the bottom and the inlet on the top of a single pass.
The stock cooler is a double pass with both in/out on one end. Even
if it was oriented with the in/out down, there might be enough flow speed to
carry any air out of it.
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Rino
Sent: Friday, October 30, 2009
1:04 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Cooling
report - was Tracy RV8
I do not know the core configuration of the Griffin cooler, it was not given to me.
The oil cooler was filled before installation to avoid air
pockets, and the lines were filled too.
The pressure sensor is at the filter and I had 90 psi there,
I conclude that the flow was ok.
The flow seems to be ok now also with the RX7 cooler but
this time it cools the oil.
----- Original Message -----
Sent: Friday, October
30, 2009 3:50 AM
Subject: [FlyRotary]
Cooling report - was Tracy RV8
Rino;
It seems very peculiar that you get
better oil cooling with the stock RX7 oil cooler than the Griffin with more than twice the core volume.
Given the low exit air temp with the Griffin
cooler, one would conclude something wrong on the oil side - flow was seriously
limited; air trapped in the cooler, maybe very poor flow distribution;
something. What is the core configuration of the Griffin – fin density, tube
configuration?
Al
The following info. might be of
interest to you, it has to do with my latest cooling system experience.
I
ordered 2 Griffin
radiators and installed that, had to modify the air ducts
A water
radiator: no: GRI-2-58185-X
CROSSFLOW
- DUAL ROW 1-1/4" tubes
core
18" X 13" X 2.75" 234 sq.
in. 643 cu. in.
A
custom made oil radiator no: CX-27256-01
core
18" X 7.5" X 2.75" 135 sq. in. 371
cu. in.
added a
spall 10" fan (15 amp.) to the oil radiator
Still
not enough cooling, could not climb at full power for more than a few minutes
before the oil reached 220 deg. F.
I had nore than eough water cooling,
so I Built a oil/water heat exchanger
and added that in series with the Griffin
oil rad.
That
did not work too well, not enough cooling.
Removed
the Griffin oil
rad. and the fan.
Replaced
it with the original RX7 oil radiator
core
17.5" X 4.5" X 2" 78 sq.
in. 157 cu. in.
Kept
the oil/water heat exchanger in series with the oil rad.
Water
rad air in 84 sq. in. air out 180 sq. in.
Oil rad
air in 40 sq. in. air out 54 sq. in.
I think
this last system works --- finally
The
outside air temp is presently between 30 and 40 deg. F. so it is hard for me to
tell how it will work in the summer but the indications are good. I
had to plaster the front of the water rad. with duct tape to raise the engine
temp. and block the oil rad. air exit to reduce air flow. The oil rad.
air flow is reduced to 12 sq. in. at the moment and not much air is flowing
through the water rad.
I have
no water thermostat and no oil thermostat so I have to control the temp with
the air flow.
I need
to build vanes to control the air flow, that is what I am working on at the
moment.
I
consider this installation much simpler and easier to maintain. The
reason I figured that the griffin oil cooler was not working properly, the air
flow behind the rad. was not getting higher than abour 85 deg. F even when
the oil was at 220 de. F On the other hand the griffin water rad. seems
to work fine. Now the air flow temp behind both rads. goes to about 130+
deg. F
A photo
of the present installation.
Renesis powered Glass Goose
----- Original Message -----
Sent: Thursday,
October 29, 2009 1:19 AM
Subject: [FlyRotary]
Re: Tracy RV8
Cooler weather is helping now but still a work in
progress. I'll write up a report when the problem is fully solved.
Tracy
On Wed, Oct 28, 2009 at 6:56 PM, <stevei@carey.asn.au> wrote:
Hi Tracy
Are you in a position to give us a further update on the cooling of the RV8.
Thanks
Steve Izett
Perth Australia
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