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My mistake Bobby, I'm working too
quickly and not concentrating enough. 775 to 800 cu" should be enough rad
volume - however isn't the inlet face area supposed to be 30% to 35
% of rad face area.
I suppose your looking for min drag?
George (down under)
George,
Have not changed the heat exchangers. Just the plumbing
and shortened the hose loop by about 18 inches. The increase from 21 to
26% is the opening size to core face ratio. I have about 272 sq in of
core face and the opens are now 72 sq in. If this test doesn't work I will be
adding a small oil to air exchanger in parallel with the oil \ water exchanger
with dedicated inlet and reducing my Rad inlets back to 21% / 58 sq
in. Actual core size is about 775 not 800 cu in as I stated
earlier.
Glad I have the molds for all this stuff.
Bobby (still wondering about Tracy's
cooling solution)
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On Behalf Of George
Lendich
Sent: Thursday, October 01, 2009 2:53 PM
To:
Rotary motors in aircraft
Subject: [FlyRotary] Re:
Activity
Bobby,
I've seen between 3 to 3.5 cu" per HP, I
guess that depends of how well the cooling is set-up, 800 cu" of Radiator
should do fine for 250hp.
If your previous exchanger was 650 cu" for 250 hp
it was undersized. I guessdamated that size form the info you previously
provided.
George (down under)
George,
I have 800 cu in of water to air exchangers. No oil to
air exchanger. At 6800 rpm \ 38" MP I'm producing close to 250 hp. But 15 hp
is used to drive the SC. So about 3.2 cu in per HP. The new openings are
about 72 sq in. The goal is to lower the water temps from 200F to 185F with
an OAT of 100F. Oil is running 20F hotter than water. With the 21% ratio I
was only able to maintain 185 HP and keep the oil temps below 220F \ OAT
95F. It all an experiment.
Bobby
Bobby,
What is your expected HP.
How does 26% of core face equate to 3 cu" for
every HP
i.e. 200 hp = 600 cu"
George (down under)
With any luck I will be back in the air this weekend.
I made several changes including opening my inlets from 21% to 26% of my
core face. Of course it's no longer 105F so will have to extrapolate the
data. Other changes include relocating the battery back to the stock
location, removing 13lbs of tail ballets, new exhaust manifold and belly
mount muffler, CO Detector, exhaust heat for cabin, O2 system, autopilot,
230 psi water spray for radiator and manifold injection (yet to be
tested), re-plumb the oil to water exchanger and a fresh pilot
bi-annual today.
Bobby
Anyone out there ??.....................<:)
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