Question for Paul McBride, the General Aviation News engines expert: I saw your recent column, “Should I pre-oil these Lycoming engines?” and I was wondering does CamGuard help?
Cold oil doesn’t splash very well, so how about preheating the engine and oil?
Bob
Paul’s Answer: Bob, I couldn’t agree more that cold oil does not splash well.
However, one of the most common ways to help the oil remain warm besides keeping the aircraft inside a heated hangar is to preheat the engine.
The basic reasons for preheating your engine are to prevent premature engine wear and tear. It certainly results in easier and smoother starts and ensures proper oil flow during the cold weather seasons.
As you are probably aware, there are several options for preheating an aircraft engine and I’ll let you decide which way is best for you. However, in my opinion, Tanis Aircraft Products probably has one of the best multi-point preheating systems.
Most people question when it’s a good idea to preheat your engine. My recommendation is that when the temperature reaches the freezing point or around 32°F, I’d say it’s time.
CAUTION: Do not under any circumstances leave the preheater turned on all the time. Doing this is more detrimental to the engine than it does good.
Getting back to the point that cold oil doesn’t splash well, you have several options regarding what type of oil you use as well.
Multi-viscosity oil has certain advantages over single weight oils, but better still are the semi-synthetic oils that meet SAE J-1899 for multi-grade oil. These oils were designed for aircraft engines operating in a wide variety of ambient temperatures.
It’s not uncommon for aircraft owners in cold climates to use these semi-synthetic oils during cold weather and then return to a straight weight oil during warm weather.
One note of caution regarding multi-viscosity oils: If your engine is experiencing some slight oil leaks, those leaks will probably increase due to the nature of the multi-viscosity oils.
Since I covered preheating the engine in a previous column, what about heating the engine oil?
In severe cold weather operations in the past, it was not unusual for aircraft owners to drain the engine oil at the conclusion of the last flight of the day and take it indoors to keep it warm overnight or until the next scheduled flight. I think those days are gone now because of the various engine preheat options and the synthetic oils now available.
Regarding your question about using CamGuard, I don’t think it would cause any harm to the engine and may even serve as a slight advantage, although I have no personal experience with the product.
You may be aware that Lycoming has approved oil additive LW-16702 that contains an anti-scuffing agent and can dramatically reduce engine wear. This product is also included in some oils supplied by AeroShell and Phillips, so be sure to check the specifications of those products.
Bob, I hope this sheds some light on your question and will provide you with some guidelines for cold weather operations.
FE Potts recommends draining the oil into a can upon landing and keep it near the fire until ready to start. Then pour it back into the engine.
http://www.fepco.com/BF.secI.ptIV.intro.html
When I was flying I’d have the plane in a warm hanger the night before. I’d preflight in the hanger.. I’d take some seat cover from the wash rack and block the scowling immediately after landing. The oil would stay warm for a 4 hour layover.
When priming wait long enough for the cold fuel to vaporize. At least 15 seconds. Don’t over heat the starter just cranking. Even a -10° F the engine should start immediately.
only if you want your engine to go to tbo. 60 yrs flying in alaska.
I just have an oil pan heater. I’ve read articles saying don’t leave it plugged in all the time. Why is that? Just preheating it when you think you’re going to fly takes two hours minimum. Plus, isn’t the cycling of hot/cold conducive to moisture formation within the engine? Keeping it warm all the time seems like the way to go. Can you elaborate on why leaving it plugged in all the time is not good? Does having the cylinder heating elements in addition to the oil pan heating element make the difference??
Please look at the Tanis website, which says you can leave the heater plugged in all the time.
https://www.tanisaircraft.com/preheating-aircraft-engines-and-preheat-products/#when-to-preheat
That’s correct but convincing people of that is another thing. Tanis has done extensive research on this and if you have a heating element on each cylinder plus the oil pan you’re good to go. Better yet add an insulated cowling cover for good measure.
I believe leaving the heat on all the time as the temperature fluctuates will tend to cause condensation in the engine which will lead to corrosion. If you heat then run the engine and get the oil above 212 degrees then you boil the water out and have less corrosion issues.
Watch the above Tanis presentation!