1961 Buick Skylark Engine 215 V8 Question

Recently acquired a 1961 Skylark with the 215 engine. Was locked up, but after a few days with Marvel Mystery Oil squirted in the cylinder's it broke loose. Seemed hard to rotated then, but eventually got freer and freer. Squirted more marvel in and left it another 2 weeks. Now it spins totally free no hang up's, etc.

Anyway, what was locking it up was the back drivers cylinder, I believe. I saw just a dime sized bit of anti-freeze come up in the spark plug hole when I got it busted loose and spinning over.

So, since no anti-freeze on the dip stick or in the oil it appears, what is my issue? Blown head gasket, or cracked head? Generally if a block is cracked, wouldn't I see anti freeze in the oil? Car shows 58K miles on it.

For some reason pic shows upside down, but you get the idea.

I would agree usually a head gasket issue but unless you know why the car was laid up anyone's guess, could have been overheated and warped the head. If it was me dealing with this I would get it running and then check for bubbles in the rad first to see if it is head related. With an intake valve open water/moisture could possible have gotten into the cylinder if left that way for a while under the right conditions. Hope for the best expect the worst. Good luck!

Thanks for the reply. i agree with your assessment, but I don't know a lot about these car's.

Before I went to the trouble to get it running I would do a compression test and/or a Leak down test. Leak down will tell you if you have a crack or blown head gasket into the water jacket and other areas. Pump it up and listing to the radiator, the carb, the tailpipe. Great diagnostic tool. Compression will tell you condition of the cylinders.

These engines were famous for overheating and cracking something primarily due to ignorance of proper antifreeze protocol with aluminum engines.