Piston

This shaft links with a piston.

The piston does not come into contact with the cylinder cover.

The settling of piston rings into a cylinder's wall is the goal of modern engine break-ins.

The timing belt ensures the choreography of piston, valve and plug continues unabated.

The Latino warrior fucked like a man possessed. His lean hips powered the pistoning rod in short, vicious jabs, so rapidly that the shit-streaked cock was a blur as it pounded Captain Randall's butthole, churning the screaming soldier's ass-juices, rectal blood, and smashed turds into a slimy froth.