P

prkaye

Well Known Member
This winter I'm not flying - we've had a very icey winter and last time I was out the taxiways were completely covered in a layer of ice. Add to that the burden of snow-blowing the hangar ramp enough to get out to the taxiway, and I've decided I'd rather just wait for spring.
What I have done is pre-head and pull the plane out every 3 weeks or so and run the engine for about 10 or 15 minutes to get the oil temps up into the green. My thinknig is that this could help prevent corrosion from starting in the engine by letting it sit for too long. Somebody advised me to talk to an AME about this, however. He said "There are some advocates who say that running the airplane at idle does nothing for corrosion, or may even increase corrosion because H2O is a by-product of hydrocarbon combustion."

What do you guys think about this? If not flying for maybe 3 months, is it better to at least do ground-runs every few weeks? If so, how hard and how long should these ground runs be?
 
Pickle it

Fly it or pickle it... A Citriba at our field ran the engine every 30 days and when a buyer pulled a cylinder to look inside, they found corrision.

If you can't fly it I would follow Lycomings long term storage instructions. This is the same recomendation I gave the Citriba owner. A lot of people have done what you are doing with no problems.
Your milage may vary.
 
Kurt is correct. If you can't fly it, leave it alone. Don't even turn the prop. Turning the prop only wipes the cylinders clean, inviting corrosion.
 
Cold

If your in Ottawa, the cold temperatures will keep most of the moisture frozen. There is very little moisture in the air at -15c anyway. I'm not sure what your weather is like this winter. If it's the same as southern Ontario, maybe none of this applies.

Something to consider.
 
The next time you run an engine, after you get on the ground with engine stopped go open the oil filler cap and watch what comes out within a short period. It is vapor of some sort (assumed to be water). I let that get out then put the engine dryer output into the crankcase vent near the muffler at the bottom of the cowl.
 
To get the water condensation from combustion blowby gases out of the oil, you need to get the oil up to at least a full 180 degrees and hold it there for at least 15-20 full minutes or preferably longer. This is only practical to do while flying. Some oils, like Exxon Elite claim to help resist internal corrosion for engines that aren't flown regularly. I don't know how true that is, but I ran Exxon Elite in my Cherokee for the last few years of ownership when it would sometimes sit for a month between flights, and there was no corrosion in it when I sold the plane last year. But then, north Texas seems to be a pretty good climate for aircraft storage too. I know of one C172 with the infamous H2AD engine in it, that sat for several years in a hangar here pending some legal action on it's ownership before it was finally released for sale, and the guys who bought it pulled a cylinder to inspect the engine and found no corrosion, so they put it back together and flew it for a couple years before a student pilot totalled the plane on a botched crosswind landing abut a year ago. That engine had been parked with Aeroshell in it all those years, and not pickled.
 
WINTER ENGINE RUNS

Hi Phil
Like yourself I don't fly my RV in the winter and here's what I do when I prepare the a/c for winter storage.

The a/c is hangared in a non heated hangar

I used Aeroshell 4F storage oil.After the oil change to 4F, i do a run up to get the engine up in temperature ( Run it for about 20 min ) then I shut it down .

After that I plunged every opening to the engine ( Exhaust,carb, breather etc ) to keep humidity out of the engine during winter.

As a final step, I removed each top spark plug and spray the inside of every cylinder with preservative oil and then install moisture absorbing plugs ( The blue ones )

During the winter I don't move the prop at all.

Every spring I look at the inside of the engine and haven't found any corrosion yet.( I had to overhaul the engine at 300 hrs due to corrosion and a shut out cam...won't happen again )

Hope this helps

Bruno
[email protected]
 
Thanks guys, good advice and knowledge here.
This winter is half-over, so I'm not going to bother pickling it, but next year I'll probably do something like Bruno suggests. This winter has been unusually warm for Ottawa, but only a few days where it's been over freezing. Normally quite cold and dry here in the winter, so perhaps there's very little to worry about.
 
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