Known for its compact diesel engines below 100 hp (75 kW), Kubota unveils its first diesel engine above that threshold, the 5-L V5009 with an output of 210 hp (157 kW) at 2200 rpm. The new 4-cylinder engine will be Tier 4 Final and EU Stage V ready when mass production begins in 2020.

With its new 09 Series of diesel engines, Kubota ultimately will expand its offerings from 100 to 200 hp. Engineers expect to have all engineering and supply work for the new V5009, the first engine in the 09 Series, completed ahead of the upcoming Stage V emissions standards, which take effect in 2019 or 2020 depending on engine output.

Aftertreatment devices include a diesel particulate filter (DPF) and selective catalytic reduction (SCR).

“The uniqueness of this engine is we are bringing out 210 hp from only five liters and four cylinders,” Ko Shiozaki, product manager in Engine Global Marketing at Kubota Corp., told Truck & Off-Highway Engineering. “If you look around, there are a couple engine manufacturers providing 210 [hp] out of six cylinders, or maybe higher displacement, but we have made it very compact.”

The engine is small enough to be easily installed in customers' current machines, he said. “Our customers have some machines that require higher output and have been asking to get more output. So we've been working to make the higher horsepower with the existing [platform], but going above 150 or 170 hp, we've got to work on something completely new,” he explained. Thus, the 09 Series engine platform, with newly designed engine block, crankcase and cylinder heads for the 5-L.

The engine design team opted for a ladder frame structure to ensure durability and maintain strong rigidity. A variety of power take-off (PTO) options have been added for different accessories such as hydraulic pumps for ease of use. In addition, the engine is equipped with hydraulic lash adjusters and an automatic belt tensioner to improve maintainability.

Shiozaki noted two keys to achieving high output and low fuel consumption with the V5009: securing the intake airflow through high-pressure turbocharging, and achieving high in-cylinder pressure through combustion matching.

“To have the higher output, we have very high combustion in the cylinders which generates a lot of heat, so we need to make it as cool as possible otherwise we will lose efficiency or we’ll lose robustness,” he said. 

For enhanced cooling performance, engineers made considerable improvements to the water cooling channel. “Fortunately, we have a foundry company within Kubota,” Shiozaki said. “Having the same Kubota terminologies, the engineers can talk with the foundry [folks] and come up with a new design.”

A 4.3-L diesel engine variant will also be available in 2020 as part of the 09 Series. It will use the same platform and footprint, with an output in the range of 120 to 130 kW (160 to 174 hp), according to Shiozaki.

“It’s exciting. This is a really big surprise for the customers because they never thought Kubota as bringing out 200-hp engines,” he said.

Applications for the V5009 diesel include construction equipment and material handling like telehandlers and forklifts, which require low speed high torque.