The vibrodynamic parameters of six-stroke engines with water injection into cylinders and engines with cylinder shutdown are considered. In both cases, a deterioration in the uniformity of stroke and torque, a decrease in the loading of the necks and bearings of the crankshaft, as well as low-frequency vibration, were found. High-frequency vibration also worsens, but less significantly. Keywords six-stroke engine, cylinder shutdown, uniformity of stroke and torque, load on the necks and bearings of the crankshaft, mean square value, vibration speed of bearings. a_yam@mail.ru