I guess if a plane sits a long time the moisture will sit at the bottom oil. I was warned about this on my engine and that's why I did an oil test. If it gets in the oil under the cam it can rust a spot on the bottom of the cam. I hear that's not uncommon on Lycoming engines. I'm not an aircraft mechanic but can't you just pull the rockers and push rods and look right at the cam lobes?

Who do you guys use to check your oil samples? I use Blackstone Labs and I like them. Here is the comments they put on the last test after 25 hrs:

JERRY: This engine had some extensive inactivity (25 years), so we weren't surprised to see some excess wear, and it doesn't look like any of these levels show a serious problem developing. Universal averages show typical wear levels for this type of engine after about 25 hours use on the oil. Aluminum and iron are both common finds in inactive engines and both should wash out nicely since this engine is starting to see more use now. Check the air filter due to silicon and resample in 10-20 hours for another look. The trace of fuel isn't anything to worry about.

I think the silicone was from the gasket sealer we used when we removed the back of the engine to put in the new oil gears and housing. I forgot to tell them about that.

If presented with a choice of buying one of two airplanes that had been sitting, one with a Lyc and one with a Conti, It'd take the Conti. The cam sits lower in the engine whereas the Lyc sits up high (and dry...of oil..eventually). Bottom ends on Conti's are notoriously tough. Not so the Lyc's. I've had both and they have their pros and cons. An engine, much like our bodies, when used and WORKED regularly, does very well from cradle to grave. Let either sit, and trouble is coming. You won't know when, but it WILL come.

Don't be to quick to buy into the semi-synthetic hype. While I am a firm believer of synthetic oils, I quit using it and wont go back.

Ram has some really good info about oils. If you have a non-turbo engine you may or may not ever see a difference. Start making oils work hard such as a turbo or super charged engine with lots of heat and the myth gets debunked pretty fast.

I have a neighbor who does the worst thing you could ever do to an engine. Every month he starts it runs it up for a couple min and then puts it back in the hangar.

And he fly's it once or twice a year for maybe 30 min whether it needs it or not. Buyer beware.........

Jaerl wrote:this engine is starting to see more use now. Check the air filter due to silicon and resample in 10-20 hours for another look. The trace of fuel isn't anything to worry about.

I think the silicone was from the gasket sealer we used when we removed the back of the engine to put in the new oil gears and housing. I forgot to tell them about that.

Jerry,
Silicon in an oil sample is silicon dioxide another word for dirt, not gasket sealer

After reading through this thread, I wonder if the best way to prep an engine for long-term storage would be to just fill it up right to the brim with oil, submerging all the inner parts in an oil bath. Maybe even fill the cylinders -- of course, this part would preclude turning the engine over.
Maybe pull the prop so the engine doesn't get turned over by accident.
Wouldn't even need to be aircraft oil- even the cheapest auto oil should do the trick.

Automatic transmission fluid is also a great preservative.

oops

I bought an old military engine that had been pickled for many years and when I got the engine and spent DAYS cleaning it up I got curious about how they did this and found out.

They would take an engine that had been tested and approved then drain the motor oil, pull the spark plugs and fill plug and actually dip the entire engine in preservative oil. They would then drain it out and install drier plugs in the spark plug holes, reinstall the fill plug and spray several very heavy coats of cosmolene on the outside of the engine. When it had a full heavy coat, 1/4 to 1/2 inch thick it was wrapped in oiled paper and packed into a metal drum or box and sealed up tight.

These things could and did sit around for decades in some of the worst climates in the world and still be good.

The engine I got was stored in a military warehouse in Russia since sometime just after WW11 and had been unpickled and tested one time since then and repacked.

It took days of effort with a steam cleaner and solvent gun with wire brushes and rags to get the cosmolene off that thing, the preservative oil was easy to flush out with solvent.

On oils the only real problem I found was with synthetic oil "Mobile One" and that was that it would not cook off the moisture from the oil, it just got milky and caused corrosion problems. Aeroshell 15/50 doesn't seem to have this problem.

PS. this stored engine worked great for a few hundred hours and then broke the crankshaft! Don't know what to say about that.

My 185 with the IO520 has been sitting in cold storage from September to May the last few years. Park Rapids Aviation has been filling the engine full to the brim with new oil in the fall, then drain it, clean it up and put in the standard 12 quarts when spring comes. Seems to be working so far and is a lot cheaper than the pickling kit I had used. Steve