Janowski engines were designed for ultralight aircraft by Jaroslaw Janowski and built by S. Polawski, both from Lodz, Poland. Information on the various Janowski designs and the engine can be found on the J1 page of the Website found here.
O-31 (2-Stroke) -- {2.756 / 2.559 / 30.5} / {70 / 65 / 500}
2cyl; Saturn 500; 25hp@4000rpm; 1969-1988; Wt = 60#.
Single-ignition, direct-drive engine suitable for tractor or pusher use; the 1972 version had dual ignition, weighed 55#, and generated 30hp@N/A rpm for Takeoff.
BGP; J70-71toJ87-88.
Applications: (Poland) Janowski J-1 Don Kichote, J-2 Polonez ultralights.