She built a new family of engines around a common combustion chamber for all motors, spending a lot of money and time on debugging the workflow. Now they have unified 24-valve heads and pistons of a single diameter - 127 mm. The in-line 9-liter “six” DS9 turbodiesel will be replaced by the “five”, preserving the volume. To balance, I had to install two balancer shafts in the lower part of the cylinder block. According to the Swedes, the "extra" nodes will not reduce the resource (they promise two million kilometers). A six-cylinder engine with standardized parts becomes already 11-liter, and with a 17 mm increase in piston stroke it reaches a volume of 12 liters.
Already three years ago, the V-shaped 14-liter G8s were discontinued. Now they have developed new V8 engines, and with unified pistons the volume has grown to 16 liters. Thanks to the modular design, the new family is easier to provide with spare parts and to train mechanics on repair features. In total, 22 engine modifications from 230 liters were obtained. with. the "fives" to 620 liters. with. V-shaped "eight".
For modern diesels, the idle fuel cycle rate is almost 10 times less than the raindrop, and for soft work it is necessary to divide it into two portions - preliminary and main, about 1: 5. Conventional fuel pump does not work so thinly, only electronics!
Unlike competitors - supporters of individual fuel injection pumps for each cylinder or “common rail”, “Scania” remains faithful to pump nozzles. At the "fives" and "eights" they are with an injection pressure of 1800 kgf / cm2. Six-cylinder pressure is even higher - up to 2500 kgf / cm2. All new engines are equipped with EGR, pre-cooled exhaust gas recirculation. Mixing them with the supply air reduces the temperature of the cycle and thereby the formation of nitrogen oxides - this is great, but the concentration of oxygen in the combustion chamber decreases - this is bad. Power is falling, fuel consumption is growing. A magic wand was found - turbocompound, a long-standing development of Scania. Part of the exhaust gas spins the second turbine installed after the turbocharger. Through a two-stage gearbox and fluid coupling, it returns about 50 liters. with. on the crankshaft, as a result, power and consumption remain at the level of engines performed by Euro III, and emissions correspond to Euro IV. There is much to be proud of the Scania engineers. After all, competitors are seeking Euro IV injection of urea solution (Blue Tech technology).