| Thanks I’ll see if I can work out where the air is flowing.
Steve
I'm not sure this fits here, but it is a surprising lesson I learned and I'd like to pass it on. My setup had a radiator on the right side of the cowl. The opening was just a few inches behind the prop, and the exit was the traditional opening at the bottom. I could not get it to cool sufficiently at idle even on a 60 degree day. I finally figured out the problem when my manifold pressure line melted on the top LEFT of the engine bay.
Air was being pushed in by the prop. As it left the radiator, it hit the firewall and turned left. The momentum carried it across the red hot muffler, straight past the exit opening and back up the other side of the engine. Basically, I had turned my cowling into a convection oven. The solution was a simple baffle to scoop the air out the exit. At 1500 RPM, the temps would stabilize at 190 on a 90 degree day. Idling faster or slower would increase temps.
Moral of the story, track the airflow all the way out of the plane.
Thanks Jeff and Neil Steve Izett
Steve, my setup will cool on the ground <80 F OAT provided that engine rpm is </= 3000 with zero wind; it will do a bit better than that if airplane is taxiing or there is a strong breeze. Both my oil air intake and radiator air intake
plenums are within a few inches of the prop. If you open the throttle during stationary ground operation you should expect it to overheat. Stationary engine dynamometers have HUGE radiators/coolers with ducted fans. Jeff From: | | Subject: | Re: [FlyRotary] Cooling | Date: | Wed, 21 Jan 2015 07:39:29 +1100 | To: | |
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| Steve, I can run full noise on the ground with no heating problems, but then I do have 900 cub inches of cooling. 600 for water and 300 for oil. I did insist that PWR make a rad that WILL cool. It does regardless of OAT. I had to put a thermostat in to get
the water over 60 degrees. I have too much cooling. Neil.
-----Original Message----- From: steve Izett
Sent: Tuesday, January 20, 2015 6:35 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Cooling
Hi Guys
So what are your experiences of running on the ground.
Do your setups cool on the ground at any throttle setting?
I’m still not in a position to open the throttle as Im in a garage at home.
After start and running at about 1500RPM (engine) with an OAT 90+
temps slowly rise till i shut it down before it gets past 210F.
This takes probably 20 Minutes.
What do you guys see on the ground in your various climates and cooling setups?
Steve Izett
Perth Western Australia |
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