The LIBERTY was born in mid 1990 after we had many requests from people looking for a small steam engine they could use in remote areas to generate power by burning fire wood.
It is a 3 inch bore by 4 inch stroke double acting single cylinder engine with a slide valve, a more robust, simpler engine one could not find.
We have supplied many Liberty engines over the years to people all over the world there being one in Tuscany Italy operating an olive crushing plant for oil extraction, another one runs part of a Eucalyptus oil distillation plant in Australia which has probably done in excess or 10,000 hours now, while a number of them are used for pumping water and the most remote one is on an island off the coast of Ketchikan up in Alaska powering and heating a cabin.
The crankshaft is made up of two casting incorporating the webs and counter weights and has a hardened steel crankpin using a greaseable needle roller as the big end bearing while the main bearings are twin 6206 sealed ball races on both sides. The rest of the engine is the same as the marine engines using the same lubrication system for the wrist pin and crosshead slide. The valve rod has a sealed ball race as well.
The valve spindle and piston rod are hardchromed steel with graphited teflon gland packing's. The piston ,cylinder and piston rings are all cast iron so providing the engine is run on wet steam and not under huge loads then there is no need for top end oil injection.
They measure approx 28" (725 mm) long by 12" (300 mm) wide by 12" (300 high) and weigh in at about 70 Kgs (120 pounds) but keep in mind the boiler weighs about 1/2 ton.

Their recommended speed is 500 rpm and provided a efficient permanent magnet alternator is used can put out up to 2 kva at around 100 psi but we always recommend running them at half pace for twice as long as you will still burn the same amount of wood but be much kinder to your engine and boiler.
These systems have the ability to heat huge amounts of water via a condenser with the exhaust steam which can be used domestically or for house heating, a swimming pool or hothouses and food drying so one must consider this as part of the package and by using a float control bypass to control the water level in the boiler you can use the boiler water over and over.

The engine in the picture below is a piston valve Liberty with Stephenson's link reversing gear and was specially built for use in a 20 foot (6 metre) paddle steamer and it runs the vessel just beautifully.