The sand on the beach at Petrel Cove in Victor Harbor comes and goes, and it does so quite regularly. When the sand is washed away during the winter months and only the rocks remain, an old, rusty engine is exposed.
My guess is that the engine was dumped over the cliffs as rubbish quite some time ago. It's more than likely that it is an old car engine, rather than a tractor engine due to its size. Then the sand returns and the engine disappears from view. The dumping of household rubbish on the side of the back country roads is still quite common around Victor Harbor and Waitpinga.