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Mark/ Jeff,
I hadn't bothered to check the size before as the
Mazda oil cooler is known to be more than adequate. If your using over the
Mazda size in cu" then your over sized. Both your cooler areas are
well over sized. I seen one chap used two Mazda coolers when taking off on water
using NOs, but he admitted it was over cooling.
George ( down under)
George,
I'm not at the hangar today, but off the top of my head, they are about 4
1/2 x 18 x 2. I had considered using two RX-7 coolers arranged in a
wedge configuration. But I ended up going with a large
rectangular unit which I chose because the air would not have to change
directions to get through the core. Hopefully, that would provide
lower cooling drag.
Mark
On Mon, Dec 14, 2009 at 1:50 PM, George Lendich <lendich@aanet.com.au>
wrote:
Mark /Jeff,
What is the Mazda cooler size., in
comparison?
George ( down under)
----- Original Message -----
Sent: Tuesday, December 15, 2009 3:34
AM
Subject: [FlyRotary] Re: Oil
Cooling
Jeff,
I doubt an air lock is/was the problem as it was oriented with the
inlet/outlet on the side. If there was an air lock, I would
think that at least part of the other end tank would get warm (which it
doesn't). Good suggestion though.
This single cooler is almost twice the size as one of your
coolers. So, it should be up to the task at hand. This is
assuming that it is working as designed.
Mark
On Mon, Dec 14, 2009 at 11:20 AM, Jeff Whaley <jwhaley@datacast.com> wrote:
Hey
Mark, I guess the only other logical reason would be an air-lock caused
by orientation … but if you’ve got two exactly the same, that is highly
unlikely.
Incidentally, I have two,
6.25”x11”2.75” oil coolers in series – I’m over-cooled with 2 but found
1 wasn’t enough.
JWW
From:
Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark
Steitle
Sent: Monday, December 14, 2009 12:00 PM
To:
Rotary motors in aircraft
Subject: [FlyRotary] Oil
Cooling
Well guys, here is a new one... at least for
me.
I've never been able to get my 20B oil temps
quite low enough for comfort.
I chaulked most of it up to the high Texas temps and an
engine that produces gobs of horsepower (just kidding on the "gobs of
horsepower" part). I'm running a 10" x 11" x 2
3/4" Fluidyne dual-pass oil/air cooler and a large (and
heavy) Fluidyne oil/water exchanger. Water temps were fine
but the oil temps would reach 240*-245* on climb, and just barely
down to 200* in cruise. I tried different plumbing arrangements,
added a cowl flap (which helped some), etc. Still, the temps
didn't want to come down. Well, yesterday I ran the
engine with the cowl off (doing some fuel
pressure monitoring/adjusting), and I had just finished getting
things up to operating temperature, verified that fuel pressure was
good, and then shut it down. I just happened to touch
the end tank on the Fluidyne oil/air exchanger and to my surprise,
IT WAS STONE COLD! I touched the other end (inlet/outlet) and it
was HOT! I thought this was odd. The only
thing that I could figure is that the dual-pass oil cooler was
defective. Since the cooler has no thermostat, I can only conclude
that the internal tank separator, which is how they make a
single-pass cooler into a dual-pass cooler, was allowing
the oil to bypass the core and go directly from the inlet
to the outlet. Well, no wonder I can't get the oil temps to
come down!!!
I replaced the cooler with another unit I had on
hand, ran the engine, and low and behold, both end tanks come
up to temp together. I did a couple of ground runs and themps
look encouraging. But unfortunately, it was too late
to do a test flight yesterday. I'm sure the new
cooler will make a big improvement. I'm hoping it
will be enough to permit me to remove the oil/water
exchanger.
Moral of the story... DON'T TAKE ANYTHING FOR
GRANTED! TRUST BUT VERIFY!!!
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