The Cessna 120-140 Association Forum

I'm sure somebody has tried this. Not sure if there are any negatives to blowing 80 degree air into the bottom of the cowling when the ambient is 10°. Maybe the fuel strainer shouldn't be heated that much? I could see where it could cause condensation inside the engine, but if you start the engine and fly it for an hour or so I would think it would be fine.
Thoughts?

Brent, see my post on: viewtopic.php?f=7&t=347

It is OK to preheat the engine, but you also have to give it some time to raise its temperature. Not sure it is a good thing to rush it up.
Then, when you fly, watch your oil temp. If you have winterized the engine by closing the 2 holes behind the prop and restricted the air intake on the cylinder, you should get a good oil temp, ie in the 180F (even got 200F today)
Then at the end of my flight i open the oil dipstick and leave like that for humidity to escape while I pack my stuff. May or may not change anything but doesn't cost me anything to do it.
And if you fly regularly in winter you shouldn't get a humidity problem.

Happy winter flying!

Thanks for the advice Martin.
I just noticed this was on the classifieds instead of the tech forum.
Anybody know how to move it? I was so proud that I got the picture attached I forgot to designate the tech forum.
Thanks

8209 wrote: ↑Sun Nov 18, 2018 8:41 pmI just noticed this was on the classifieds instead of the tech forum.
Anybody know how to move it?

Yes, I do. Done!

I was so proud that I got the picture attached I forgot to designate the tech forum.

That heater looks a lot like the one I use in my hangar. It gets a lot hotter than 80 degrees! You can ignite paper at the outlet. I'd think that, unless it mixes with ambient air, it might be a little too hot to feed directly into the cowl.

You can stick a meat thermometer in the plenum and monitor the temp there. I'd keep it below 150.

Thanks on both accounts John.
Yes, I know for sure it gets hot close to the actual heater. This was my first try at preheating with this set up and I was right there checking the temperature of the engine components with my digital temp gun and the ducting was definitely hot, but the oil sump and bottom of the case didn't get over 100° in the 30 minutes or so I ran the heater. Of course the ambient was 10° F. I will have to experiment some more, but I will be careful not to overheat.
Thanks, Brent