>Instead of
>a medium-volume ticking noise, it now alternates between a really loud
>tick/clack and a really loud rattle (with engine speed held constant).

And the rod bearings are literally oozing out around the crank journal,
paper-thin from being pounded on. As they ooze out little bits of schrapnel
break off and are circulated by the oil pump, of which you will need a new
one, getting hung up in the oil cooler, of which you will need a new one,
and scratching every single thing in your crankcase.

Happened to me, too. ;)

--Ken
  68 Westy, 71 Bus