Abstract: An internal combustion engine for vehicle propulsion has a number of cylinders arranged in two parallel planes and connected to two crank shafts within a common engine block. A selectively operable clutch is fitted at at least one of the crank shafts, and a gearing coordinates the output from the two crank shafts. A coupling is provided between the gearing and the output shaft of the engine plant.

Abstract: A vehicle power plant comprising a number of engine working cylinders arranged in two groups with different numbers of cylinders and/or with different power outputs, the parts being individually connectable to a common power take-off shaft by a continuously variable belt transmission. A gearing, including a reverse step, is mounted with its axes of rotation parallel to the crank shafts of the engines and connects the belt transmission to the vehicle output shaft. This vehicle power plant produces good fuel economy, high top power output, low exhaust emissions, and good acceleration capacity.

Abstract: A ceramic turbine rotor fitted to a metal shaft has an integral shaft stub, extending into the hollow end of the metal shaft, and is resiliently retained therein. In order to prevent relative rotation between the rotor and the shaft during torque transfer, the stub shaft and a clamping and tightening member, within the metal shaft, are provided with interengaging parts. The stub shaft, the clamping member and the hollow metal shaft may be formed with mating, interengaging corrugations and grooves running substantially axially. The stub shaft may alternatively have a polygonal cross section, and the clamping member and the void in the hollow shaft will then have mating, but successively bigger cross sections.