Lanz HN 1

The 12/20 HN Verkehr carries a thermosyphon-cooled single-cylinder engine of 4,767 cm3 displacement, running on multiple fuels, producing 8.8 kW, or 12 hp, at 760 rpm. The machine weighs 3,250 kg and measures 2,875 mm in length, 1,630 mm in width and 2,300 mm in height.

Multi-fuel capability allowed the engine to run on a range of fuels, including lower-grade ones, and was a key selling point for Lanz engines of this era against pure diesel units. The name suffix "Verkehr" points to a version set up for road use, as distinct from a pure field version. Thermosyphon cooling dispenses with a water pump and relies solely on the natural circulation of heated coolant.

When buying such an old multi-fuel single-cylinder engine, the condition of the pre-combustion chamber and ignition arrangement matters most, since matching spare parts are barely available new any more. The thermosyphon cooling needs an undisturbed, deposit-free circuit, and the flywheel, clutch and frame should be checked for cracks after up to a century of possible use.