Ed, you are absolutely correct. When I spoke to Don Swords, he told me he had a customer from Florida who returned an engine with corroded cylinder bores and stuck rings, etc. The guy said he went to the airport and ran the engine "all the time", but Don's point was he never ran it long enough to build up to normal operating temperature, so he was actually doing more harm than good by introducing moisture into the cylinders and not burning it out. The Continental Service Manual describes how to preserve an engine. After finding corrosion in my cylinders and seeing the damage it has done, I'm a big believer in preserving engines when you aren't flying much!
Dave --- In [email protected], "Ed Burkhead" <e...@...> wrote: > > > > Don wrote: > > When looking to buy, I found many "low time" > > engines, that had been majored decades ago! > > Someplace there is a "guess" as to how it was > > stored for those years. I finally chose one that > > was fairly low hours (125 hrs SMOH) and 14 > > years since overhaul! Fourteen years is a long > > time, but I satisfied myself that the engine had > > been run frequently enough during that time > > to make it a good gamble in my eyes. > > > The old standard advice was that a non-flying engine should be started and > run a little while once a week or so. > > When I got grounded from diabetes and wasn't able to get around it, I got > severely aviation-depressed (though, fortunately, I felt fine all the reset > of the time when I wasn't thinking about flying). I didn't want to think > about flying and didn't even visit my plane for a year at a time - it hurt > too much. I had done nothing to "pickle" it. > > When I decided to go back to flying even if it was with someone else to be > pilot in command, I looked into lots of references about sitting-idle > engines. Finally, still unable to get past my medical rejection, I looked > for a good home for my baby. > > By then, the preponderance of what I found was this: > 1. It is bad to start the engine and run it for a short time. Combustion > moisture and any incoming air moisture doesn't get evaporated and > accumulates. > > 2. If you are going to start the engine, it should be run for around 45 > minutes - time enough to get it to operating temperature and for any > accumulated moisture to be vaporized out of the oil. (i.e. fly it if it's > in annual or a long temperature monitored ground run if necessary) > > 3. It is best to pickle the engine for best storage and seal all openings. > > 4. If, for some reason, it doesn't get pickled, it's best if it just gets > parked after the last flight and not turned over or run at all until it's > possible to do a proper warm-up and boil-it-out engine run (i.e. a flight). > > My engine fell into category 4. When checked out, it looked good and ran > well and seemed not to have any corrosion issues from having sat. Honest > disclosure was necessary when I finally decided to sell it. It's been > several years with its new owner and still running well on the 1984 > overhaul. > > So, experts, what is the CURRENT, BEST information on engine storage and > engines left idle or run rarely? > > Ed >
