[Sirrotica]

If you have coolant in a pan, it has rust inhibitors in it, and will sit for a long period if time without rusting the metal. Rainwater/condensation has zero rust inhibitors in it and when mixed with used motor oil the sulfurs in the oil form sulfuric acid. We've all seen what sulfuric acid does to battery trays.

I've seen cars parked that were run with plain water in the oil parked, and sometimes within a year the oil filters will rust through the can and leak out. Of course the oil filter can is much thinner metal than the oil pan is, and will rust through much sooner. I've also seen dipsticks rust off on the ends when sitting with water in the pan. I've seen rainwater freeze inside of the pan and distort the pan quite a bit, same as a piece of cast iron breaks when water is left in an engine, and it freezes.

Lots of unusual things come into play when used oil, and water are mixed together inside of an engine, and it sits for extended periods. Just relaying some of the experiences I've had dealing with engines that have sat for years, and someone tries to start them. Sometimes you get lucky, and the engine seems to not have suffered catastrophic damage, sometimes it does. You're guessing, and hoping luck is on your side, I would rather lay eyes on it, and know for sure what's happened inside of an engine that has sat, and the oil has been contaminated.

I have a 455 that I rebuilt for a friends Trans Am, that also has rain water in it from sitting outside. I know what probably has happened inside of the engine and will be taken apart to see if the water got up to the crank and bearings. The oil pump being rusted up is one of my major concerns, if started with the gears unable to spin, it will possibly break the oil pump shaft when turned over. plus push all that corrosion inside of the pump right into the lubricated parts inside of the engine. I'm not going to rely on good luck to save me a little labor, not worth the chance of destroying a low mileage 455, that I rebuilt, that ran very good when parked.

The engine is still free when I put a socket on the dampener bolt, so it is a good engine. I won't chance starting until I look at all the insides of it, and clean it up from water sitting in the pan. I plan on putting it in my next project street car, an 84 GP.