New Generation V8 − Refined power for demanding operations
8 JUNE 2017
Scania V8 trucks are made for drivers and operators who demand high average speeds, enduring value and power. The new generation V8 offers all of these qualities – and improves the owners’ profitability.
Simplified yet refined
Scania is continuously improving its products. And the all-new V8 engine is another leap forward in the company’s offering. The new V8 builds on many of the successful features from the earlier generations. But this time, out of approximately 650 components that make up the entire engine, 200 are completely new.
The cross-functional team that developed the new V8 engine focused on four key areas: fuel efficiency to improve customers’ profitability, serviceability to increase the vehicles’ uptime, improved production processes to increase quality for even better robustness, and a contemporary design to match the New Generation Scania trucks.
Fuel efficieny at the heart
Several factors have contributed to improved fuel efficiency, such as reducing the number of components and introducing components that are engaged only when needed. In the following paragraphs the most important ways that a better fuel-efficiency has been achieved are highlighted.
While the 16.4-litre cylinder block remains the same, the complete engine weighs approximately 80 kilograms less than its predecessor. This is mainly due to a simplified engine layout with fewer parts overall – for example, the exhaust gas recirculation unit has now been removed. Consequently, the new V8 trucks have a higher load-carrying capacity.
SCR only – made possible by the new exhaust gas eftertreatment system
The new V8 engine meets emissions legislation together with decreased fuel consumption by increased aftertreatment efficiency. This has optimised the engine for fuel efficiency and power to a larger extent than when partly reducing emissions with exhaust gas recirculation (EGR) and conventional aftertreatment system. This also results in better engine breathing, which helps to improve fuel consumption.
The new aftertreatment system includes improved evaporation, improved SCR catalysts (selective catalytic reduction) and an improved diesel particulate filter. The new aftertreatment system is an enabler for reaching Euro 6 emission levels without the need for an EGR.
Rotated twin scroll fixed geometry turbo
The new rotated twin scroll fixed geometry turbo is common in the racing industry, but this is its first use in the heavy vehicle industry. The fixed geometry increases efficiency and results in a 0.5 percent reduction in fuel consumption. The new turbo unit also allows for a higher boost pressure, resulting in improved combustion.
The turbo unit also helps reduce the overall weight of the engine. This is because the exhaust manifolds meet in the turbine housing from both sides instead of meeting in the turbo manifold, as they did in the previous generation, which was a more expensive and heavy solution.
With the introduction of a single bank exhaust gas manifold, the overall weight of the engine has been reduced, while at the same time the legendary V8 sound has been improved.
Variable coolant pump
The coolant pump utilises a viscose coupling that is only engaged when needed. This results in adjustable cooling, which means that less coolant is pumped through the engine when it is not needed. Lower friction losses and the reduced energy used for pumping help to decrease fuel consumption by up to 0.5 percent.
Pilot-controlled oil pump
The new pilot-controlled oil pump adapts the oil pressure to the necessary amount at every moment. This helps to minimise the friction losses in the engine and results in a 0.5 percent reduction in fuel consumption.
The introduction of an oil thermostat has reduced the fuel consumption between 0.5 and 1 percent. The thermostat provides faster oil-pressure build-up during cold starts and, more importantly, maintains an optimal oil temperature under normal operation.
The Miller camshaft used in the new 520 hp V8 engine reduces airflow through the engine at low load. This in turn increases the exhaust temperature, which helps to reduce the fuel consumption by 0.5 percent. At high load, compression work is moved out from the engine to the turbo compressor. More energy is extracted from the exhaust gases, which increases engine efficiency. This is possible because the inlet port is held open for a longer time and the effective inlet stroke is shorter than the expansion stroke. This will over-expand the in-cylinder gases, with more power to the crankshaft for the same amount of fuel.
The new clutch compressor engages automatically when needed. This helps to reduce fuel consumption by approximately 0.5 percent, while at the same time reducing noise emissions.
Increased service ability
The completely new engine layout gives service technicians better access to the engine when servicing a vehicle. This means a more robust engine and reduces the time spent in the workshop, thus helping the vehicle owner achieve higher profitability.
The development team left no stone unturned in its quest to improve serviceability. The new single high-pressure rail, for example, makes failure diagnostics easier, which improves the vehicle’s uptime. And the slotted holes on the intake manifold flange also make life easier for the service technicians should they need to remove the intake manifold for some reason. With the slotted holes, only the two top screws need to be loosened completely; the two lower screws will support the heavy intake manifold while it is being worked on.
Improved production process
The development team has optimised the manufacturing process and introduced small but ingenious solutions to minimise the risk of mistakes in the assembly. One example is a small mesh grid covering a hole where there was a risk of losing small objects that could harm the engine. In the process, care has also been taken to improve the ergonomics for the people actually building the engine on the production line, the slotted holes on the aforementioned intake manifold being one contribution. The end result is an engine with an even higher quality than previous generation engines.
The new engine layout in itself makes the engine look different. Details such as the rocker covers, charge air pipe, heat shield and high pressure pump have also been designed to visually fit the New Generation Scania trucks.
Improvements in current engine platform
The new V8 engine platform ranges from 520 to 650 hp. The current engine platform will still be used for the 730 hp version Scania V8 engine. It has, however, not been left untouched. The updated 730 hp will for example feature the pilot-controlled oil pump, the variable water pump and the new larger aftertreatment system as well as an updated engine management system, which will improve its fuel efficiency – especially at low load.