Was setting up the distributor for my Crate 360 Magnum today...Engine turns easily (feel the compression of each cylinder) with breaker bar. Have had engine stored for 2 years, with mystery oil in the cylinders. Periodically rotated it to keep valves from sitting.

Pulled #1 spark plug, and rotated to TDC, and thought while I had the plug out would be a good time to use my new Camera scope that my wife got me for xmas. Took a peek, and the top of the piston while under a film of mystery oil, also appears to have some rust deposits. Put a towel down into the cylinder to soak some of the oil, and there's maybe a fine amount of grit in the oil, but it disperses/dissolves when I rub it between my fingers. Checked a couple of other cylinders and they are clean. Don't see any rust on the cylinder wall of #1, but camera resolution even with light isn't perfect.

Is there cause for concern and do I need to tear it down, or am I being worried for nothing, considering I see cars that have sat for 10 years being cranked with some carb cleaner?

 

probably not rust, pistons are aluminum alloy, whether cast or forged. aluminum doesn't rust.

 

I hate to do this as I am not sure but this makes me think it might be a drip of moisture from the bottom of a valve or the head.

 

hmmm...youre right. But there's countless threads about rusty pistons...maybe the carbon buildup rusts? It's definitely orange and looks like rust.

 

Do the rings rust and seize?

 

Are you asking in general or particularly about my situation? In mine, I can rotate engine easily with breaker bar. I have read in general about pistons siezed to the walls with rust.

 

Not sure, either one....my Plymouths (1954's) were seized, and it was the rings. So maybe the rings are rusting in yours, and when you turn the engine the rust moves around?

 

I wonder if it would be worth while to perform a cylinder leak down test? Assuming that passed, I would run it as is.

 

Your question was twofold -> do you need to tear it down OR are you worrying for nothing. IMO, you are probably worrying for nothing. There are several opportunities for rust in ANY engine,, and the moisture that is needed to promote it could come from almost ANY source - including condensation. Put that engine in the vehicle of your choice, run it, and enjoy it. You won't have any trouble....... FredT