A compact four-stroke opposed engine with a displacement of 140 cm³ and an increased service life of the cylinder-piston group has been developed in St. Petersburg. The new design allows for the replacement of worn liners without a complete replacement of the cylinder block, which simplifies repairs and extends the service life of the power unit. The developer was OOO "Scientific and Production Association "AMB"".
The development is primarily aimed at aircraft-type unmanned aerial vehicles and other small-sized equipment where the engine operates under high mechanical and thermal loads.
The main feature of the new design is replaceable cylinder liners made of high-strength cast iron VCh80 with a tensile strength of at least 400 MPa.
The power unit is designed according to the classic opposed scheme with two cylinders, equipped with air cooling and a carburetor fuel system. The engine's displacement is 140 cm³, and the compression ratio reaches 11:1.
According to the developers, tests showed an increase in the service life of the cylinder-piston group by approximately 40% compared to the closest existing design. This result was made possible by combining wear-resistant cast iron liners, their external finning, and the ability to replace worn elements without disassembling the entire cylinder block.
The authors of the development expect that such a design will increase the operational reliability of compact internal combustion engines used in unmanned aviation and other equipment where small weight, durability, and ease of maintenance are especially important.