Question Cold weather ops and constant speed props

[Neal]

While I have done ground runs over the past two months of non flying I have not cycled the prop since the last flight in early December. It's been insanely cold here in VA with single digit nights. Yesterday I went to fly as we're warming up (35F OAT) and did get about an hour of preheat. At runup I was at least 135F on the oil temp but oddly the prop would not cycle until about 5 attempts.

Curious how other cold weather flyers handle this, what they see, etc. Any concerns?

No issues in flight and did fly the flight at 24 squared to keep temps up.

 

[ve6yeq]

My plane is almost always tied down outside. Using Aeroshell W100 (55 F minimum starting temperature) with CamGuard, Reiff engine heater, and the standard Bruces Custom cowling cover, the first prop cycle will be very slow in 30's F weather, but by the 3rd one, it will be operating normally. The oil pressure will also remain slightly higher than usual until after the 3rd prop cycle. I have also had it basically not cycle until after a few attempts, but that was in the 10s F.

The people I have talked to said this is to be expected in very cold weather, as the prop hub is not preheated and will still be very cold. I have received a suggestion for an insulated prop cover.

 

[ve6yeq]

From what I have read online, a cold constant-speed prop hub is not really harmful as long as you cycle it until hot oil is flowing before takeoff, and I have never read anything about it getting cold again in flight. The oil cooler, though, is an issue when it is cold. There are many photos online of oil coolers "blowing up" when hot, high-pressure oil is suddenly forced into them as the Vernatherm kicks in, so it is important to pre-heat the oil cooler.

This is a different problem from the oil temperature never exceeding 190°F in winter (the temperature needed for oil to evaporate). I have never had this problem on my Cub, but I have read online about many people partially blocking airflow to the oil cooler in cold weather.