Abstract: The invention proposes an electricity producing assembly comprising a steam engine coupled to an electric generator (19), the steam engine comprising at least one cylinder (11) and piston (12) assembly (10), a mobile coupling (13) between the cylinder (11) and a drive shaft (14) of the electric generator (10), and a timing device (15) comprising a timing bottom part (16) controlled by a cam mechanism, and a timing top part (17) comprising at least one valve and connected to the bottom part (16) by at least one valve operating stem, and an oil-based lubricating system (201), characterized in that only the timing bottom part (16) is served by the oil-based lubricating system (201).