Nature of the problem
Aircraft piston engines are susceptible to damage from rust and corrosion due to two primary factors.
- Because they are air cooled, these engines collect moisture quickly via condensation on critical internal engine components. This condensation can happen daily due to the diurnal temperature cycles, particularly in moist humid environments. As the temperature drops overnight, it approaches the dew point. Because the engines are air cooled, the engines cool rapidly providing optimum surface temperatures for condensation to form. This happens most quickly inside the tops of the cylinders, due to the cooling fins on the cylinders. Any cylinder with an open exhaust valve is exposed to outside air through the exhaust system. This leads to moisture condensing most quickly on the open exhaust valves, dripping into the cylinders, shorting out the sparkplug electrodes, and running down the inside of the cylinders into the crankcase. This moisture results in rust formation on cylinder walls, valves, valve seats, other critical engine components, and contributes to the formation of acids in the oil. This acid then attacks additional components such as bearing surfaces and bearing races.
- Piston engine aircraft frequently are not flown often enough. The two primary aviation piston engine manufacturers, Continental and Lycoming, both recommend flying an aircraft regularly to reduce the amount of moisture that has collected inside the engine, and to insure critical engine components do not lose surface lubrication. (Ref. Lycoming Service Letter L180B, Lycomng Flyer Reprints page 65 “Frequency of Flight and its Effect on the Engine”, and Continental SIL 99-1)
Best intentions don’t work
Despite a person’s best intentions, it is impractical, and sometimes impossible to fly an aircraft as often as necessary. Work, family, schedule, weather, sickness, being out of town, aircraft maintenance, and a myriad of other things seem to conspire to stop us from flying as much as we intend. Because of this impracticality, there needs to be an alternate method to prevent moisture from collecting inside these engines.
The elephant in the closet
There is a another source of moisture that collects in our engines, that no one talks about. The massive amount of moisture left inside a hot engine after flying.
This moisture will re-condense inside the engine as soon as the engine cools below the dew point of that air. Dew points of that hot air are typically around 130° F. The hot water, condensing into the hot oil and combining with other combustion by-products, creates an optimal environment for acids to form in the oil. These acids then attack critical internal engine components. The only solution is to get that hot humid air out of the engine before the engine cools to that dew point.
The only practical solution is an automated system that:
- Connects quickly and easily to an aircraft engine
- Can be connected to the engine shortly after flight
- Quickly removes as much moisture from inside the entire engine as possible (Crankcase, exhaust and intake components)
- Keeps the inside of the engine as dry as possible on a 24/7 basis
- Can be used on aircraft stored inside hangars and on aircraft tied down outside
And, provides feedback so you know it’s working