FIELD: mechanical engineering; internal combustion engines. SUBSTANCE: engine has cylindrical spool 2 with port 10 on its side. Spool is rigidly coupled with crankshaft 3. Spool 2 provides periodical communication of space of crankcase 1 with compression spaces 6. Angle between axes of cylinders 4 connected by bypass line 8 is set within 120 and 160 deg, depending on number of cylinders; this angle is equal to central angle of arc of circumference corresponding to length of port 10 in plane square to axis of rotation of crankshaft 3. EFFECT: enlarged operating capabilities. 2 dwg
