ljsmith1

Did you take out the starter yet? If not, the grinding noise may be the starter gear hitting the flywheel - or a little rust in the cylinders.

*Most* hydrolocking does not occur during running as the volume of water leaking into the cylinder is typically too low to actually fill it up very quickly. It will probably turn to steam before that happens. However, if you stop the engine, the water will drain into the manifold or block, and then into the cylinder, and then when you go turn it over - hydrolock. The starter is not powerful enough to damage con rods. In rare instances, a cylinder head jacket might crack, and allow copius amounts of water in a cylinder while the motor is running. If the leak volume exceeds the volume of the combustion chamber in between cycles, a con rod will bend because the water will not compress.

Maybe the riser bolts were not correctly torqued and re-torqued after heating. Also, if the mating surfaces were not very clean, that would cause quite a leak. I assume that you used a new gasket (S.S. Shim stock, Teflon/graphite coated type) with no sealer. Stock risers require 30-35 ft lbs of torque. I use lockwashers under mine to prevent loosening.

If the stud was brass, odds are you might not have any other significant damage. If you have it together at this point, might as well throw a new starter in and fix the riser and fire it up.

Good Luck!