Originally Posted by SWGA Boater
Motor is out of boat. Have engine mounts off, alternator, brackets, raw water pump, fuel pump, etc. pretty much everything except waterpump, manifolds and carb. Was thinking of reinstalling freeze plug and then do a coolant pressure test as suggested (if possible). I did not see a crack or anything around the plug hole.
If you truly want a good nondestructive test for cracks (hairline included) take the engine to an engine shop and get them to do a magnet particle test on the engine (typically on the heads and any suspect area from visual observation). Very easy to do, should be inexpensive, and is effective.
You can do the test yourself with the right equipment. Takes a kit (magnet prod and particle matter) and a 110v outlet.