Abstract: In a turbocharged internal-combustion engine, especially a Diesel engine, the turbocharger air delivery is arranged to match the air demand of the engine at low r.p.m., with the suction duct of the turbocompressor being provided with a throttle valve actuated to prevent the permitted charging pressure from being exceeded at higher r.p.m. by means of a regulating valve responsive to the charging pressure of the turbocompressor the actuation threshold of which is set to the permitted nominal supercharging pressure.

Abstract: Internal combustion engines are turbocharged by operating a turbocompressor with exhaust gases from an internal combustion engine. Compressed air is fed from the turbocompressor to the engine at a rate such that all the air compressed by the turbocompressor is fed to the engine when the engine is at the highest altitude for which the engine is designed and is operating at full load and is running at its lowest normal operating speed. But when the engine is operating at lower altitude and/or higher speed and/or at less than full load, then some of the air compressed by the turbocompressor is automatically discharged.