flyrotary@lancaironline.net Mailing List Archive

Regarding cooling. Take heart, it's probably something simple. Sometimes smart people working on complex systems tend to think so fast and furious that they over think things and forget to check the simple things first. I know it sounds ridiculous but check all of the "obvious" things first. Do you have cowl flaps that somehow closed and screwed up the air flow. Is the air intake size proportionally sized to the exit. Is the water pump working?

From: Jeff Whaley <jwhaley@datacast.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wednesday, April 25, 2012 11:49 AM
Subject: [FlyRotary] Re: N774CG, RV-10 20B first flight

Congratulations Tim.

Your first flight sounds a lot like mine, except as you say my temps weren’t quite as high as yours and never experienced a boil over upon landing.

I’ve got a slow-poke (80-90 mph climb speed and 110-115 cruise) so I can relate to your test flight conditions.

I agree with Bobby; a set of pictures would help us a lot in helping you. Without the photos what I can say is: ensure your coolers are in a high pressure air stream; ensure you have an absolute seal on the intake plenums to your coolers and make sure there are no obstructions to outlet airflow within 10-12 inches on the back side of your coolers.

Questions:

Why do you fill your expansion tank? – I would suggest leaving an air gap of at least 1/3 at the top.

Do you have an air bleed hose from the front of your engine back to the expansion tank? – This is pretty standard for most other rotary installs.

Do you have a thermostat/bypass hole open or plugged?

Belt driven water pump or electric?

What are your coolant hose diameters?

Jeff

:	"Bobby J. Hughes" <bhughes@qnsi.net>
Subject:	RE: [FlyRotary] N774CG, RV-10 20B first flight
Date:	Wed, 25 Apr 2012 10:50:15 -0500
To:	"Rotary motors in aircraft" <flyrotary@lancaironline.net>

Tim,

Congrats on your first flight. Pictures and cooler sizes would really
help. Once you do some initial trouble shooting and changes you could
limit your HP during take-off and climb. The RV10 climbs better than a
C172 at reduced HP. I think I set my electric MT prop to 2200 rpm and
didn't use any boost for the first few flights. Still could get 800 fpm
climb. 7000 rpm on a 3-rotor is a lot of HP to cool.

Bobby Hughes
RV10- Renesis

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Tiffanie Holt
Sent: Wednesday, April 25, 2012 10:16 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] N774CG, RV-10 20B first flight

Well, got up this morning and did the first flight on the RV-10. OAT
55 Degrees at 7000 ft. Did the taxi to the runway and the water temp
was 168 and oil was 150. Everything looked full power in and off we
went. She has plenty of power, RPM was 7000, and here comes the temps.
I immediatelly turn to down wind at 80kts and the water temp
came up to 220 and oil at 200. Turned base and temps still climbing
still at 80 kts, turned attention to land vise temps. I landed
immediately and taxied back to the hangar and the temps peaked at 245
water and 240 oil. She got hot, I got boil over once I shut the engine
down. I took all the cowls off to help the cooling of the engine.
Check everything over, turned the prop and listened for any unusual
noise, checked the oil and could smell the 2 stroke oil in it, which I
understand is normal.

She Flew, but not what I expected on temps. These are the highest temps
that I have seen so far. I had 11 hours on ground runs, but I did not
let water temps get above 205 and oil temp normally stayed at 180.

At the hangar, I let the temps get to 180 on water and 160 on oil, I
filled the expansion tank back up and ensure there was coolant and
started her back up to see if I had normal readings. Oil pressure was
on the rise, oil temp was at 175 and water temp stabilized at 190, Just
wanted to ensure I did not do damage to the engine and that she would
start. She was a little hard to start, but started purring like a kitten
again. Shut her down, and then started her back up and she immediately
turn over.

Did not run her much longer, had to shut her down and get to work.

Are there any suggestions or inspections that I will need to do on the
engine for the high temps?

Things I plan to do before next run:
1. Oil Change, Filter Clean: It is time for a cleaning and I can inspect
the oil.
2. Flush the radiator: Ensure everything looks normal 3. The highest
point in my water system is the expansion tank, but the water return is
at a level slightly below the expansion tank. I plan to install a
fill/bleed valve in it to ensure all the air is out of the system.
4. Move the Water Temp Sensor from the block to the return line to the
radiator 5. Place the Louvers in the cowling. I did put the louvers in
per Van's Plans, but I put then in the cowl to help pull the heat from
the exhaust system.
6. I will also open up the inlet to the Radiator as well. The standard
Sam James Cowl has a 4 3/4 inch Diameter opening, I will open it up more
and give it at try.

Any suggestions would be greatly appreciated.

Tim

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