whatever was put on cylinder base to seal it is WRONG.
it looks like rtv was used when it should only be the stock base gasket....that is part of your problem and im sure a huge airleak.And detonation is ocurring/or cylinder is not even sitting flat
looks and sounds like the connecting rod bearing is toast.
sadly...it's time for a full rebuild..... crank rebuilt, new main bearings and seals, and topend