Cold Weather Preheating

[CTMI]

Tomorrow I want to fly to an airport, then leave the plane for about 6 hours on the ramp, then fly home.

Its going to be 20 tomorrow. I have a Tanis. 

So my thought is plug the tanis in when I get there, but is it not advisable to plug the preheater in when the engine and oil are at operating temps? 

If not, I suppose I could get a timer that would click on after an hour or two of cooling.....

OR

Maybe I don't have to plug it in at all? I have a sleeping bag I've repurposed as a cowl blanket, maybe that will keep it warm enough? 

I know there's a lot of cold weather flyers here, any thoughts? 

[FredG]

I'm located in Iowa.  I routinely plug in my Reif preheat system right after a flight.  I am aware of no problem with this approach.  I suspect that, after six hours outside, a 912 will have little remaining heat from a flight, even with a cowl blanket.  Hard to know how your engine will start at 20 degrees F.  I think a well tuned engine with properly gapped plugs, a fresh battery with a full charge, and the right amount of choke will probably start at that temperature, but there can be any number of reasons why an engine could have trouble starting at 20 degrees F.

[Ed Cesnalis]

mine is plugged in 24/7 for 8 months (except when I'm flying) so I plug it in with warm oil all the time.

We have seen some coolant leaks at the head and think the constant Tanis use encourages that failure, but its only a few drops that sits on the head when it leaks.