Scania reveals how they squeeze an extra 3% fuel savings from their new V8
Posted: 28-Oct-2020 |
Scania’s constant quest to develop its V8 engines further continues into the 2020s and the result is even more fuel efficient engines suited for the most demanding transportation tasks.
“We build upon Scania’s vast V8 experience and continue to improve what generations of skilled engineers have learnt, created and achieved before us,” says Göran Lindh, Chief Engineer for Scania’s V8 engines. “There are no quantum leaps, it is all about refining things and adding the latest technology. The new EMS enables a smarter and more advanced engine control software with higher accuracy. We can, for instance, calculate more precisely how much fuel that is needed and when.”
The EMS (Engine Management System) interacts with the AMS (Aftertreatment Management System). They are both highly critical to meet the current and coming Euro 6 regulations regarding NOx and particles. (And not only when the truck is new, but also over time; the legal demand is at least seven years or 700,000 kilometres.)
Scania has added a new solution where AdBlue fluid is actually injected twice: once directly after the exhaust brake and a second dose at the “normal” position in the silencer itself. With the extra dosing, the evaporation of the AdBlue is improved during low load cycles since the temperature is higher near the outlet manifold. With the extra dosing, the aftertreatment strategy is improved and also contributes to better fuel efficiency.
The updated V8 range is now equipped with a new high-pressure fuel pump where the pumping elements are individually controlled (AIM, Active Inlet Metering). The overall pressure and inlet control will be enhanced with improved diagnostics for increased uptime and performance. The new pump is also optimised for minimising engine oil consumption. Also, the compression ratio and the maximum cylinder pressure has been raised, to further improve combustion and fuel efficiency.
An ever-important aim when designing modern, high-performance engines is to reduce internal friction. By reducing internal losses, substantial gains have been achieved. One alternative is, of course, to use thinner, more effective modern oils with qualities that were unheard of only 10–15 years ago. But the tremendous improvements with more advanced long-life oils in recent years are not sufficient. The engine itself must also be developed to make use of the new opportunities.
“Raising the pressure and the power output requires that several components inside the engine, including gears, pistons, rings, cylinder heads and valves, are refined and reinforced,” says Lindh. This necessitates advanced fine-tuning and improvements
to reduce internal losses, especially since we also wanted to extend maintenance intervals and strengthen durability. I am proud to say that we have managed to reconcile these somewhat conflicting objectives”.
The most impressive member of Scania’s V8 family is, of course, the new DC16 123 engine. With its massive output of 770 hp, it replaces the previous top-of-the-line showpiece that sported 730 hp. A difference between them is that the 770 hp V8 is based on the same, updated platform as the rest of the new V8 range, delivering the same level of outstanding robustness that all Scania’s V8s are renowned for.
“Here the biggest difference is evident,” says Lindh. “The increased power comes together with fuel savings, savings that we were able to reach thanks to the introduction of the latest technologies. It has a SCR-only after-treatment system, a robust, fixed geometry turbocharger and the same kind of single-bank exhaust manifolds as the other three V8s”.
Shedding certain heavy components and simplifying others, has lowered the weight by up to 75 kg, compared to its predecessor. Another novelty is that the 770 hp engine, for increased responsiveness, has a unique, fixed geometry turbocharger with ball bearings rather than traditional journal bearings.
“The new single-bank manifolds actually come with a little perk,” explains Lindh. “Not only are they lighter and more efficient but they also contribute to the distinctive V8 sound, the typical blur that so many Scania customers and V8 fans appreciate. It does not generate more noise but this is rather the result of how the exhaust gases are allowed to collide, due to the firing order, inside the manifold on their way out.”
“These are truly magnificent engines, with a short, sturdy crankshaft and smooth power delivery from the multi cylinder configuration. Our famous Scania V8s are without comparison when both transport efficiency and load carrying capacity are in the equation,” says Lindh.