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Don't know about the Renesis engine, but the older 13B had
two coolant sensors, one in the rear iron housing and one on the pump/thermostat
housing -exit from the engine. The one on the rear housing was connected
to the temp gauge on the instrument panel, the one on the pump housing was used
to control the radiator fan. It was set to turn the fan on when the
coolant leaving the engine reached a temp of 207F.
However, most measure the temperature exiting the engine -
which may be a bit warmer than measured on the rear rotor. The reason (I
believe) for this practice of measuring coolant out temps is that early on
- the only factual data around was from Racing Beats Technical catalog on
the Rotary engine. They recommend not letting the engine water temperature
out of the engine exceed 185F. However, The do state that a low temp rise
to 200F is unlikely to hurt the engine as opposed to a rapid rise due to a bust
coolant line, lost fan belt, etc.
I also think that the fact the fan temp sensor was
not set to turn on the fan until an engine out coolant temp reached
207F indicates there was a bit more margin than the 185F limit
Racing Beat advised. Also I would think the engine designers would have
the fan come on before reaching the critical limit to provide a bit of a safety
margin - but, that is just my opinion.
That coolant temp limit with the earlier engines was based
(I believe) largely on the fact that in the earlier engines the Achilles heel
was the inner coolant "O" rings which did not handle higher temperatures
well. My first tear down of the engine was early on in my
flight testing where I failed to get all the air out of my system and
had the engine get hot. It turns out the stock O ring seal had failed due
to elevated temperatures.
However, Once we started using TES O rings, I
believe that removed that Achilles heel failure point and moved the temp
limit up. I know that myself (and many others) have temperature
excursions past 200F ( Tracy Crook and I have had coolant temp
increases to 240F for short duration without apparently ill effect).
Again, not recommended, best to always keep the coolant at 200F
or less, but it does not appear to do any apparent damage if a temporary short
duration excursion.
FWIW
Ed
----- Original Message -----
Sent: Saturday, October 06, 2007 10:13
PM
Subject: [FlyRotary] Re: Coolant Water
Pressure
Mark,
Yes I will be there
on Saturday. I suppose it is too much to ask for you to fly your plane
there??? :>)
You know, I think my
360 degree kink is going to require around 40 knots in order to have the
energy to make all those turns….Right now a 120 knot test is going to require
a trailer hitch! J
The location for the
temp measurement is basically stock. The stock sending unit was metric
and too large to use with the one that came with the EM-2, so I plugged it and
tapped a smaller hole on top as opposed to the stock location on the side of
the inlet. I was wondering why the stock location measured temps
incoming to the engine if it is better to measure outgoing
temps.
Bill
B
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mark Steitle
Sent: Saturday, October 06, 2007 7:48
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Coolant Water
Pressure
Looks like you've made great progress since we last
spoke. It shouldn't be long now. Are you planning on
attending Tracy's (actually, I should say Laura's)
rotary roundup? Lots to talk about.
Concerning your cooling system, I assume the air
comes in the backside of the radictor? What kind of inlet & diffuser
did you use? I measured my airflow today through the radiator. It
flows 40 knots at 120 knots IAS. It may be a little fast. You may
want to measure yours, when the time comes.
You mentioned that you were measuring coolant
temperature after the radiator? I think you also need to measure it as
it leaves the engine. This will tell you how hot you're running and how
close you are to redline. Just the opposite as for the oil.
If those hose clamps are not constant torque clamps,
please consider upgrading them before first flight. They're available
from McMaster.
Keep up the good work. Hope to see you at
Tracy's.
On 10/6/07, Bill Bradburry <bbradburry@bellsouth.net>
wrote:
Ok, I recently
upgraded my computer to Vista and had to
download some software to get my camera to talk to it…So here are some
pictures of my cooling install
Notice the bypass
hole that you guys are talking about needing to plug. This hole is in
the housing which has been removed, so it is not a player.
The little rag you
see on the oil line is a high tech way of checking for a leak. (I have
one!)
The red wire is the
air temp sensor for the air after the radiator. It is on top of the
fan.
Hoses are 1 ¼"
The temperature sensor was moved from the left side of the inlet to the
top
But is reading
temperature as it enters the engine after the radiator. (coolest
place)
My overflow catch
can. I will be replacing this with a pressurized on as per Lynn's suggestions in a
previous post in order to introduce
An air cushion above
the liquid under pressure so it will not be
"locked".
I am planning to try
and put suction on the cowling at the exit with a leaf blower in addition to
the prop blast and the small fan to see if an increase in
Air flowing will
help. I haven't checked the sides of the radiator yet as I have been
alone when running the engine….
All inputs
appreciated. I already know some things should be changed, so don't hold
back with the suggestions.
Thanks,
Bill
B
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