FIELD: heat engines. SUBSTANCE: heat engines that convert low-grade heat into mechanical or electrical energy, using different types of low-boiling liquids for specific conditions as a working fluid, and can be widely used in the national economy. A two-phase gravitational engine contains a thermosyphon with a housing partially filled with liquid and a turbine installed in it, the turbine being made of vapour-liquid type. Moreover, a thermosiphon is used, in which the lower evaporation chamber and the upper condensing chamber are connected by a vertical steam pipe for the vapour-liquid mixture. The lower part of the pipe is equipped with a funnel, the edges of which are adjacent to the inner surface of the engine housing along the circumference. In the area where the funnel adjoins the inner surface of the housing, check valves are installed around the circumference, and in the upper part of the steam pipe in front of the condenser there is a cut-out in which the turbine is installed. The steam line pipe is equipped with a nozzle the size of the turbine inlet, and the turbine shaft is brought out through the housing wall. An annular fine-mesh filler with high thermal conductivity is introduced into the lower evaporation chamber, and a condenser with cooling fins is inserted into the upper condensing chamber, inside of which a part of the steam pipe connected to an inverted glass is inserted; holes are also made in the condenser, and an additional funnel having an annular gap with the body is placed below them. EFFECT: new design. 2 cl, 1 dwg.