Scania Adapts On-Highway Diesel for New Off-Highway Engine Platform
Scania Power Solutions tailors engine variants to suit unique requirements such as transient response in excavator operation and power generation.
Scania Power Solutions has launched a new engine platform designed to provide new power outputs, longer service intervals, longer base-engine operational life and reduced carbon dioxide emissions. The engines will be available for industrial, heavy machinery and power generation applications. Series production is due to begin in 2024.
The starting point for the new platform is the 12.74-liter inline-six-cylinder diesel engine designed for Scania’s road-going vehicles, which was launched in late 2021. This engine delivered a claimed reduction in fuel consumption of 8% and thermal efficiency approaching 50%. Design features include dual overhead camshafts and a single cylinder head casting, replacing the individual cylinder heads of the previous engine.
For Scania Power Solutions, there will be two new engines. The first is a variant of the 12.74-liter engine described above; the other is a five-cylinder inline variant offering a capacity of 11-liters. The 13-liter variant provides a range of power outputs between 368 and 450 kW (493 and 603 hp), while the 11-liter engine offers power outputs between 202 and 368 kW (271 and 493 hp). Scania also claims that torque has risen by up to 21% compared with the current engine.
For the 13-liter engine, Scania Power Solutions claims that fuel consumption is reduced by up to 7% compared with its predecessor. The company also suggests that the period between service intervals could be up to 25,000 hours.
“Power Solutions within Scania is a synergy business area, which means that we derive the products from our colleagues working with the on-highway business and then we adapt the engines for the particular segments that we work in, whether it’s industrial, power generation or marine,” explained Henrik Nilsson, Power Solutions product management director at Scania. “That strategy has stayed the same for a few years. What changes of course is the application areas and the legislation that we work with.”
Fuel consumption and the working life of the engines were key focus areas for the development team. Nilsson says that because the engine was a completely new design, the team was able to focus on what really matters. “We’ve done everything we can in order to achieve the fuel consumption goals and the life length,” he said. “It goes down to the placement of the cooling channels in the engine block and the rigidity of the engine block and the new cylinder head. There are differences in the oil system, small differences, but it makes a huge difference when talking about longevity.”
To reduce fuel consumption, Scania has pursued traditional practice in reducing internal friction, while improved cooling has allowed the compression ratio to be increased. Engine calibration also has played a part. “I would say it’s a quite big combination of hardware development and design, together with calibration and know-how about the industries where we operate,” Nilsson said.
Balancing fuel consumption and transient response
One reason why Scania quotes a fuel-consumption reduction of 8% for the road-going engines and 7% for the Power Solutions variants is because of the applications for the engines. While road-going versions are offering around 50% thermal efficiency, there are other factors to consider for the Power Solutions engines, according to Nilsson.
“Our customers have in some respects other requirements as well, which is transient response in excavator operation and power generation and it’s a balance between the two,” he explained. “So, I would say that the guideline was not the overall efficiency of the engine as such, but to make the engine based on the truck engine and make it tailored to the applications that we’re supplying. By that we are decreasing the fuel consumption, depending on operation by some five to seven percent.”
The need for good transient response means that Scania has paid attention to turbocharger control, too. “When we work with industrial applications where we had a high customer or application demand on transient response, then we put a lot of effort into optimizing how we control our variable geometry turbo to make sure that we get as high an efficiency as possible,” Nilsson said. “Then, not only measuring efficiency, but measuring the transient response and how the engine will behave in a certain operational cycle where you have a lot of transients. To just say that we increased turbocharger efficiency alone is maybe not enough. It’s really related to the application – where you install the engine and how we can control the VGT in that application specifically.”
These engines are likely to be operating in harsh environments and in a wide range of ambient temperatures. This has meant that Scania has focused on cold-starting ability for some time with the current engine platform. “Now we’ve made a big leap forward,” Nilsson said, explaining two reasons for the improvement.
“One is an electrical feed pump. Cold diesel is very slow moving, so that is one thing, we can push the fuel through the system,” he said. “And [the second is] the sensor measuring where the engine is rotating, [determining] when we should inject the fuel. That improves capability at lower engine speeds. We’re able to sense the position of the engine earlier in the starting process, so we don’t have to get up to a certain engine speed before we can start injecting fuel.”
Reducing operating costs is not only about reduced fuel consumption and extending service intervals. Engines that are easier to service save time and potentially cost in maintenance programs.
“If you look at our current engine lineup, we don’t have all the service points on the same side of the engine,” Nilsson said. “With this new engine, we’ve tried to gather them in the same area location-wise on the engine, to make it easier. We can service from one side rather than having service points spread out on the engine. We are also offering various options of cartridge filters and spin-on filters, depending on customers’ demands. So, from that perspective, with a spin-on filter, in some applications it is easier to service as well.”
The engines have been designed to conform to the emissions regulations in markets with the strictest legislation, effectively Europe, the United States and China. This means conformity to EU Stage 5 for power generation and industrial use, China Phase 4 for industrial applications and U.S. Tier 4 Final certification level. “All these engines will be available for non-regulated markets, where we can really focus on CO2 optimization and fuel efficiency,” Nilsson said.