Abstract
The effects of the air pollution due to the running cars, trucks and buses, strong manifested in the last years, imply powerful measures to the Diesel engine designers and manufacturers, imposed by legislative limits, which have been adopted in Europe - ECE-UNO 24 and 49 Regulations, more and more stringent through recent amendments. In order to achieve the targets to reduce the exhaust gas emission, meaning obeying the limits for total hydrocarbon, nitrogen oxides, carbon monoxide and particles, the research work in the field of the internal combustion engine must be highly activated, equally for new designs as for old running engines. The recent pollution taxes in Romania will have the effect to support the programs regarding the toxic emission abatement for new and used Diesel engines. The present material shows some solutions already applied in production process for a 10 liter Diesel engine and a proposal for old similar engines, in major overhaul in order to improve performances and mainly to reduce pollutants in the exhaust gas.
Keywords: diesel engine, direct injection, injection pressure