Originally Posted by michau32
Could you explain how valves work? I can't imagine it. Maybe you can attach some drawings?
The valves consist of a rod that is a close sliding fit in its hole, and the rod has two narrowed down sections that connect the piston to the air/steam inlet at the top of the stroke, and connects the piston to the exhaust at the bottom of the stroke. Rather than have an exhaust tube, the valve rod just extends out the top of the block, connecting the piston opening to the open air.