Aviation From My Rocking Chair: What Does ‘Pickling’ Have to Do with Airplanes?

Howdy to the gang at Chapter 430. This month I’d like to write a little about engine preservation or ‘pickling’ during extended storage.

Let me set the scene; You have been working on that airframe for a year, but have no engine as yet, and you really need one so mounts, cable runs, controls, and systems can be installed. About this time, a friend calls to tell you he found a great deal on an engine, and do you want it? After inspecting the powerplant and finding it in good shape, you decide to purchase it for your project.

So…you now have an aircraft which still requires months to finish, and an engine which will probably not be operating until the project is completed. In order to be sure your powerplant is ready when the airframe is, it must be protected from corrosion and acid buildup damage. Here is how that can be done. Note: This procedure is slanted toward air-cooled aircraft engines, but will work equally well on any reciprocating engine. A. Lycoming 1) Drain oil from tank and refill with Aeroshell Fluid 2F, or Poly-Fiber ESO (Engine storage oil). 2) Remove top spark plugs and slowly turn engine through 2 revolutions by hand. Let engine stand for 10 minutes, and then turn engine back and forth through 90 degrees for 12 cycles. Drain preservative oil. 3) Spray exhaust valve and port of each cylinder with piston approx. ¼ turn before Top Center on the exhaust stroke, using preservative oil.

4. Spray approx. 2oz of preservative oil in each spark plug hole.

5. Seal breather openings with oil and moisture resistant caps.

6. All accessory drives which have oil seals must be coated with preservative oil before installing covers. 7) Install spark plugs in the bottom holes and dehydrator plugs (AN4062-1) in the top cylinder holes. Attach ignition leads to the lower plugs and ignition cable protectors to the top leads. 8) Install covers on exhaust ports and all other openings.

7. Exposed cadmium plating or machined surfaces should be protected with a corrosion preventative such as LPS-2 or -3.

8. Periodically inspect your engine for signs of corrosion. If you find any, the affected area should be cleaned and the engine re-preserved.

B. Continental

1. Remove top and bottom spark plugs and spray preservative oil (same type as for Lycoming) in the upper spark plug hole of each cylinder with the piston down. Rotate crankshaft as each pair of cylinders is sprayed. Stop crankshaft with no piston at Top Center.

2. Respray each cylinder without rotating crankshaft. Move spray nozzle from top to bottom plug hole being sure to cover cylinder interior completely with preservative oil.

3. Reinstall spark plugs.

4. Spray approx. 2oz of preservative oil through oil filler tube.

5. Seal all engine openings with plugs and non-hygroscopic tape (don’t use masking tape!) 6) And lastly, if the engine has been preserved with the propeller on, be sure to hang a sign on it which reads: “Do not turn propeller. Engine preserved.”

I realize this all sounds like a big hassle, but when it comes time to install this jewel, it sure is nice to look inside and see nothing but sparkling steel and aluminum!

Well, thanks again, Troopers for your kind attention. Repeat after me, “The blue side goes up and the brown side goes down” till we meet again… Rick Vaux TC4130