I'm sure that if Tracy were starting with a blank slate he might
do his cooling system differently. But, he's already racked up
an
impressive number of hours with his evaporator cores. It would
be
a major task to go back to a different design at this point.
I've had the benefit of watching this newsletter and I'll build
a
cooling system the way that I think it ought to be done. Go
ahead
and slag on Tracy's cooling system if you want, I'll see if I
can
build one that I think will work better, but until I do, I'll
sit
on the sidelines and try to learn from others.
If anyone is interested in what my cooling configuration will
be,
it's a stock gen II oil cooler with a C&R radiator that's twice
the size of the oil cooler. They will be mounted next to each
other underneath the engine, with a scoop right underneath the
spinner, which is(will be) 16" dia and 5 inches forward of the
stock placement of the prop hub. There will be a duct going from
the scoop to the heat exchangers. I hope to have the airplane
done
in 12-18 months.
I'm sure Tracy will be flying way before I am.
Brian Trubee
-> Gary Palmer wrote:
Hi Brian,
The system you describe is almost exactly like Perry
Casson's Glastar installation. He has had no cooling problems
whatsoever. A beautiful job, but you better be prepared to do a
lot
of custom cowl fibreglass work. Check it out at
http://eaa154.dhs.org/perry/engine/index.shtml
I agree with Monty's comments on engineering compromise.
So
often, these "critiques" and differences arise because there is a
lack of clear statement of design objectives; I think Monty's
comments are bang on in this regard.
If your objective is maximum power, and damn the noise, a
peripheral port exhaust and intake make a lot of sense; on the
other
hand if a quieter, nice neighbor type of installation is your
objective, you will lean towards the Renesis because it is easier
to
keep the noise down.
If you have a fixed pitch propellor, tuning an intake
system
for max torque at lower rpm's seen during takeoff seems
appropriate,
rather than at max rpm that would be appropriate for a constant
speed prop situation. Both are valid approaches depending on
objectives.
Different strokes for different folks and goals.
Tracy's design objectives IMO have always leaned towards
making the rotary installation affordable and reliable. I believe
he
has succeeded admirably in that regard with his redrive, and FI
computer. His cooling systems work at low cost, and avoid a lot of
cowl modification, a not insignificant advantage for many
builders.
Arguably not the most efficient lowest drag solution, but
certainly
good enough to win at Sun n Fun. Sounds like he met his primary
design goals.
Eaking out the last few percentage points of performance
can
be a consuming and expensive challenge, and for those inclined to
chase that goal, go for it. There is lot's to be learned from all
points of view, and always room for improvement, that is what
makes
this hobby or disease, as a good friend once called it, so
rewarding.
Let's just keep the debate at a professional level so we
can
maximize the return on everyone's investment, and not lose
valuable
contributors. I notice after several years of mainly lurking, that
we are getting better & better in that regard.
my 2 cents worth..........Gary
Gary Palmer
Lancair 235 C-GPLM
13B powered RV in the planning stage.
President EAA Chapter 245
http://eaa245.dhs.org/
gpalmer@NortelNetworks.com-
I had a lot of trouble with that web site with two different browser.
shtml gives the source on the html.
Can you capture the pictures of the left and right side of the engine
and up load them here Gary?
Here are the 2 cowl jpegs. BTW, I am surprised you had problems since
Perry is a Linux guru and maintains our chapter web site for us with
Apache IIRC.............Gary
Paul Lamar
Yes. That is almost exactly what I had in mind. I am not surprised it is
cooling well. Very good work Perry.
Paul Lamar
Ben Schneider wrote:
I sure would like to see more of Perry Casson's installation, are there
more pics available, and where is he located? Looks great. Looks like kind
of what I had in mind.
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