|
|
Ernest's recent cooling experiment inspired me to try the same. I
spent about 1/2 day building the test setup shown in the photo. I
don't have a sensitive flow or pressure meter so I tried using a water
manometer. I pointed the end at the surface of the radiator like a
pitot tube. Net result, the flow is so slow by the time it exits the
radiator that I got no indication at all on the manometer. Not helping
is the fact that I'm not testing one core, but both water cores and the
oil core together. I did get some qualitative data by holding a strip
of paper against the surface. There was some airflow coming thru the
cores over the entire surface.
I put the tip of the manometer a foot or two directly in the cone of the
apparatus (what else can I call it?) and got a pressure of about 1 inch
of watter. Putting it directly in the end of the leaf blower was about
3 inches. So I need a bigger leaf blower!
Since the test didn't tell me a whole lot, I put the prop on and
started the engine. This is the first time I've run the engine with
the cowling on. It was about 90F, and the temps came up slowly to
180-190F. I ran the engine up to 4000 rpm for a while until it started
running very poorly due to vapor lock. Photo 2 is an early picture of
my exhaust system. Oil and water temps went up to 200-210F and were
still climbing.
Basically I have a can sitting at 1000F+ heating everything up. I know
that I have to shield the thing, but I just haven't gotten to it yet.
When I took the cowling off, everything on the hot side was too hot to
touch, including the fuel lines. One nice touch, I have a small cooler
to cool the fuel as it returns to the regulator. It's mounted on the
engine mount about 3 inches from the unshielded 1000F can so it's doing
a great job _heating_ the fuel. The cooler was for the zero return line
fuel system I was thinking about. I'm not going to do that however. The
fuel will be returned to the tank. The exhaust also radiates heat into
the left radiator.
As of now, I believe the cooling system is doing pretty good, but won't
be able to tell much more until I get the exhaust system shielded.
Bill Shertz' pipes straight out of the cowling looks kind of attractive
right now. :) Bob W.
--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/
|
|