Storing Your RC Engine By James Goss      How do you store your glow engine when it is not being used on a project? If it's going to be idle for a few months I simply us after run oil and inject it in all ports of the engine while rotating the prop. This seems to prevent any rust build up inside the engine. If it is going to set for more than a couple of months I will also place it in a zip-lock bag which helps keep moisture from it.  Remember that steel can't rust without oxygen and moisture. This is how oil helps prevent your engine from rusting; it isolates the surface of the steel from the surrounding oxygen and moisture.  So the key to long-term storage of an engine is to keep it away from oxygen and moisture. Don't leave it setting out in a damp environment such as found here in the south.      The time it takes metal to rust depends on the amount of oxygen and moisture present, along with temperature. Think about a ship that has been at the bottom of the sea for hundreds of years. The rust action is very slow because of the lack of oxygen. So either one of the two components missing will prevent rust, but these two guys tend to travel in a pair.  Here are some methods that I have used in the past:      One sure-fire way to prevent rust is to store your engine in a big mouth glass container, large enough to hold the engine, and fill it completely with kerosene. While the engine is under the kerosene rotate its shaft to purge or pump out all of the trapped air. All the parts will remain lubricated and with a sealed cover on the container the engine will be protected for many years. This is a really good method to use, especially if it is an expensive engine and will be out of use for a long period of time.      Another method is as follows: Give your engine a kerosene bath and dry it off. Place tight fitting carb covers on the carburetor and also on the exhaust port from the muffler.  This basically seals the engine other than the muffler pressure tap is still open. Connect a short peace of fuel tubing to the pressure fitting and plug it with a check valve. This is another use for the check valve that we talked about in the article  “Fuel Tank Pressure”. Using a small hand operated vacuum pump, remove the atmosphere from inside the engine by squeezing the pump. Rotating the prop a few times will expose all the internal parts of the engine to the vacuum pump. The check valve will enable you to remove the vacuum pump without loosing any of the vacuum. Place the engine in a zip lock bag as quickly as you can and use the vacuum pump on the bag also. The reason I say as quick as you can is because the engine will probably start to leak around the shaft and begin to loose some of the vacuum. The way the vacuum removes the moisture is as follows: When you operate the pump the atmospheric pressure inside the engine is reduced toward a vacuum. In a vacuum water will boil at about 50 degrees F.  The water will steam, even at low room temperature, and be sucked out by the pump. Thus we have removed most of the moisture and oxygen to prevent rust. Another example of using a vacuum to remove moisture is found in air conditioning servicing.      If you don't have a vacuum pump place your engine in a zip lock bag as was stated above. Use a vacuum cleaner to suck out the atmosphere and reseal the zip lock bag. Place electrical tape on the top edge of the bag to ensure the bag does not leak. Even though there is some air left in the bag the chances of rust forming in the engine is greatly reduced.      Another method that I have used in the past also works.  Flush the engine out as above with kerosene. Get a piece of felt cloth large enough to wrap the engine in and saturate the cloth with kerosene. Secure the felt around the engine with twine and place it in a zip lock bag. It will last for years. I chose felt because this material has good capillary or wick action to retain the kerosene or what ever oil you use. I got this idea from working with electric motors, which use felt to lubricate their brass bushings.        I think cost of the engine will be the final determining factor as to how well you preserve your engine for future use. In some cases I have removed an engine from a plane and set it on a shelf for 10 years. Of course after 10 years it would be frozen up and would need to be taken apart and cleaned, but the engine itself would still run fine.  Then other times an engine might show signs of rust after a few months of setting on the shelf, go figure.  Keeping in mind that a ball bearing engine has more  steel in it to rust, you may want to use a little more care with them.