Rotax 912 question

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Flightlevel

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I am installing a 912 on a project. It previously had a exhaust cuff to supply cockpit heat. I am considering using the coolant system to heat the cockpit. It would be the typical diverter valve to a light weight heat exchanger fan combo back to the coolant system. Has anyone done this? Does anyone see any problems? Your input is appreciated. Flightlevel
 

TFF

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I haven’t seen one. Where you dump the heater coolant is just as important as where you take it from. Autos tend to have both at the thermostat housing/ pump area. You don’t want to make one set of cylinders hot and the others cool. Whatever you do, you should instrument it before and after so you know.
 

mlkAvEAT

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The Rotax powered planes I've flown have all had muffler heat or no heat, but I know Edge Performance sells a coolant based cabin heater kit. You could try reaching out to them or one of their North American distributors to see what experience they have with it.

 

bhall55

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Exactly what I have installed in my sling2 with 912is engine. Works great, even in wisconsin winters.

Bill
 

Flightlevel

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I am glad to hear it's working well for you. I plan to tap into the cooling system between the upper collection reservoir and the radiator. Would like to know what diverted valve and heater controls you used. Thanks
 

Map

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Pulsars with the Rotax 912 have very simple and very effective cabin heat: part of the hot air behind the coolant radiator is routed into the cabin. In this installation the radiator rests at an angle against the firewall, so all that is needed is a hinged steel valve in the firewall right there. I have used this for years and have not had CO in the cabin from it.
 

Flightlevel

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That is very interesting. I will have to see if I can find any info on the Pulsar installation and see if I can adapt that system to my aircraft. Do you have any pictures of your installation that you would share?
 

13brv3

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I believe the RV-12 does the same thing, with a baffle that dumps radiator exit air either to the cowl or cabin as determined by a baffle valve. Anything that keeps liquid out of the cabin would get my vote.
 

wsimpso1

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I am installing a 912 on a project. It previously had a exhaust cuff to supply cockpit heat. I am considering using the coolant system to heat the cockpit. It would be the typical diverter valve to a light weight heat exchanger fan combo back to the coolant system. Has anyone done this? Does anyone see any problems? Your input is appreciated. Flightlevel
Rans offer such a system as a heat supplement. My wife’s Rans S6 has one and it works nicely.
 

Jim Chuk

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Mar 30, 2013
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I have the 912 engine in my Kitfox, and use a thermo-bob thermostat to keep the coolant temperature up in the winter. The thermo-bob has a bypass line on it, and that line runs through a heater core in the cockpit. A computer type fan blows air through the heater core when I want heat. I do notice that the heat is reduced at times, I think that is when the thermostat is open and coolant flows through the regular route. I've thought about a valve in the main hose to force more coolant through the heater core at those times. One would have to monitor coolant temps then a bit more though. I think my next Kitfox will have the coolant flowing through the heater core before the bypass line. It's just harder to find a heater core with 1" lines. I did acquire a small radiator from a Phazer snowmobile that should work though. JImChuk
 

Map

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Here are pictures of the Pulsar cabin heat concept. The "radiator" sketch shows were the radiator is, the valve is in the firewall near the upper corner of the radiator where it touches the firewall, it is hinged at the top and opens forward, operated with a cable (other pictures). The cable other end has a knob on the instrument panel.
 

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