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Rotax-cold air flying

D

dick seiders

Well Known Member
Flight today was first in 1c temps and my oil temp. hung around 165 max. and the water coolant radiator put out an unsatisfactory level of heat for the cabin. Additionally the cold air pouring under the front of canopy dictated putting some weatherstripping in place which I will test tomorrow. I looked at threads from last years cold months and saw some interesting baffles for both cooling radiators. (Larry Geiger) Has anything else developed since or are those baffle ideas still the best solution? Thanks for feedback.
Dick Seiders 120093
 
Hey Dick

put in the search box - "RV-12 I have Real Heat". It worked great last winter, and now that it is getting cold again. Work as good as possible.


John Bender
 
Oil Temp

Dick,

You may also want to either install a thermostat in your oil line or cover approx half your oil cooler with a piece of scrap aluminum or your oil temps will never get high enough to evap any water out of your oil.
 
Cold Weather flying, etc...

Is there a certain temperature that we need to think about engine preheat? Even down here in Dixie, the thermometer is flirting with the 30 degree mark.
thanks
Meade
#16
N612RV
 
Hey Meade

The Reiff System works this way for me. When temps are say 20 F, if you do not cover the cowl, and leave it plugged in over night, it will keep the engine about 75 degrees ( inside hangar ). If you put a packing blanket over the entire nose and tuck it in at the air inlet in front, it will allow the engine to get up to about 90 degrees. I can pull the plane out, and immediately start to taxi to one end or the other, and by the time I get there, it is RTG ! Saves warm up time and gas. I also have the Thermostasis 98% Oil Therm, so the oil is ready to go quickly also.

John Bender
 
Hey John, oil thermostat sounds like the way to go. Thermostasis website doesn't specify a model and prices currently are $195 including the barbs. Is this your unit, and might we have a photo of your installation? Thanks.
Dick Seiders
 
Hey Dick

If you live in a moderate or warm climate, and the oil gets to 190 or better most every time you fly, not sure I would bother. For us in the colder climates, you will not get the oil up to temp very fast at all. You can burn up a lot of fuel trying to get it warmed up. That is where it is the best. It cuts warm up time in half, whether in warm or cold weather.

John Bender
 
Last edited:
When the oil thermostat is installed how do you purge all the air out of the system. When installed the oil lines to the thermostat the oil cooler is opened up and there will be some oil loss. When doing the Rotax air purge the thermostat is in bypass mode and will not remove the air between the thermostat and the oil cooler.
 
What I do

I remove the oil cooler during oil change, turn it upside down to drain, and drain the tank. After putting things back together with new oil to the top of the tank, I remove at least one set of plugs, and turn it over until the oil pressure comes up to about 60 lbs. I let it set for a few minutes, then turn it over again for maybe 20 - 30 seconds just to verify the pressure comes up instantly, and stays solid. The way I installed the Thermostasis unit will mostly purge itself. New oil coming in will move to the cooler since the one cooler hose goes down hill from the thermostat. When I start it for the first time, I watch the oil pressure until it has run for a couple minutes. I have never seen any hesitation in pressure readings. It works for me.

I don't think the 'purge' system Rotax recommends would be a problem if you have the oil and engine in a warm environment. Cold oil and engine might slow down the cooler self-purging.

John Bender
 
Hey John, it's true it's not that cold here in Atlanta, but a few days ago at 1c (4000ft) The oil temp never got over 165. That's too cool. I may try Larry Geiger's oil cooler cover to see if that handles it. If not will go with your method.
Dick Seiders
 
Hey Dick

In your area, that sounds like a good idea. The Thermostasis Oil Therm is NOT easy to assemble. Takes some serious work to get the hoses pushed onto the fittings etc. Works great, but you likely don't need it.

John Bender
 
Oil Change Technique!

John Bender, when you say,"let it set for a few minutes, then turn it over again for maybe 20 - 30 seconds ". Are you doing this by hand?

THXs
John
RV12 N1212K
 
NO -

I always use the starter. With one set of plugs out, there is minimal stress put on the moving parts of the engine. I just let is set to give any possible air in the cooler system to get to the top of the thermostat, then turn it over with the starter again to be sure all air is out.

John Bender
 
Remove oil cooler?

John, I assume you meen the oil radiator-- I had one heck of a time getting mine to seal and stop leaking, so I'm not real interested in removing it every oil change. Oil temps about 160-190 right now and will get cooler, though, so something needs to be done. Do you use some type of sealant on the blue fitting threads?

Wayne 120241/143WM (12 hours)
 
Yes, and yes

I used Loctite 'blue' to start with on the BLUE fittings on the oil therm, and then permatex over that because most of the oil system is suction, and I wanted stuff that would stay in place. I very much trust the 'blue' sealant, but went with the other just for a secondary back-up.

Wayne, not sure why you had a seal problem at the oil cooler ( rad ). Did you have a scratch on the fittings on the 'rad' ?

John Bender
 
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