The new Volvo Penta D9: Electronically controlled marine diesel engine combines performance with maximum comfort

Volvo Penta’s new D9 diesel engine offers very high performance characteristics combined with low exhaust and noise emissions as well as minimal vibrations resulting in a high degree of onboard comfort. Available in two power output alternatives, 500 and 575 horsepower, the Volvo Penta D9 is a powerful alternative for flybridge boats, sportcruisers and sport fishers of about 40 to as much as 50 feet in length. Due to its compact format, the D9 does not occupy much more space than the Volvo Penta 7-liter TAMD75, but it offers almost 100 horsepower more and 30% greater cylinder volume.
The new in-line 6-cylinder marine diesel engine with a cylinder volume of 9.4 liters has a great deal in common with the larger D12 engine, with which Volvo Penta is market leading in its segment. Together with the highly popular 7-liter TAMD75 engine, Volvo Penta has had the strongest product program for inboard diesel engines in the industry.

The addition of the D9 will further strengthen this program.

“With the D9, the aim has been to develop an engine that would give higher power output and even better torque characteristics than the TAMD75, without having larger external dimensions. Using modern technology and several advanced technical solutions, we achieved this aim,” says Thorbjörn Lundqvist, Volvo Penta’s technical project manager for the D9 engine.

The D9 was developed for the entire Volvo Group, which implies significant coordination advantages and access to the latest in diesel engine technology. The engine is built entirely in Volvo’s automated engine plant in Skövde, Sweden. The plant has designed its assembly line to be able to perform the marine adaptation, resulting in a high and consistent level of quality.

New turbo for even better torque characteristics
Volvo Penta’s marine diesel engines are known for their torque characteristics, optimized for their marine applications, which creates rapid acceleration on to the plane and low load sensitivity at cruise speed. The new D9 is no exception.

The 575-horsepower version has a torque of not less than 1,910 Nm at as low as 1,500 rpms. During the acceleration phase, the D9 is a full 35% better than the TAMD75 – an engine that is highly rated for its excellent acceleration resources.
The high torque is due to the combination of large cylinder volume, electronically controlled unit injectors and, particularly, the completely new turbo. This is a center-mounted, twin-entry turbo that creates the possibility of pulse charging. This means that the power in each exhaust pulse can be used to produce charge pressure, which enables the engine to respond very quickly at low rpms. The charge-air cooling is highly effective and create a low temperature in the intake air, which is an essential prerequisite of the low emission levels.

The turbo is supplemented by electronically controlled unit injectors that at 1,800 bar produce a good fuel-to-air ratio. Four-valve technology also helps ensure the efficient flow of gas.

New generation of electronic control and EVC
The electronic control system of the D9 is called EMS 2 and it was developed by Volvo to meet the coming emission requirements. Faster, more effective electronics make it possible to monitor and control additional engine functions – for example, the engine fuel requirement is analyzed up to 100 times a second. The EMS 2 ensures that the engine always receives the right amount in all operating conditions. The result is a fast response to the driver’s commands, low fuel consumption for long cruise range and minimal exhaust emissions.

The low exhaust emissions will meet overall emission requirements that are to be introduced in Europe and the US in 2006 and satisfy Volvo Penta’s own, very stringent standards regarding smoke.

The electronics also include further improved monitoring. The condition of the piston rings is monitored by the EMS 2 and the level of cooling fluid is also monitored by the system. Engine, controls and instruments are all integrated in Volvo Penta EVC – Electronic Vessel Control – which makes installation simpler and improves operating reliability. EVC, which is based on CAN bus technology, makes it possible to replace all cables usually required for instruments and control with a single serial data cable. Electronic control for shift and throttle is standard.

Highly robust basic construction
Due to its powerful, robust basic construction, not only does the engine have a long life and high degree of reliability but the level of comfort is also enhanced due to reduced engine vibrations. The D9 has an very powerful engine block that is further strengthened by a fully cast cylinder head and a special ladder frame bolted onto the bottom of the engine block. In-line 6-cylinder configuration that allows room for a well dimensioned crankshaft with large bearing surfaces also helps to produce low vibrations.

Compact and service-friendly
“The D9 was developed to be easy to install, even in confined engine spaces. Compact exterior dimensions are an essential characteristic, but the D9 is also fully symmetrical, which further simplifies installation. Due to the absence of service points on the front edge of the engine, it can be mounted right against the fore bulkhead,” says Thorbjörn Lundqvist.

All important service points are easily accessible, making daily inspection a simple matter. For testing, error detection and diagnostics, Volvo Penta’s service technicians use the new, common tool, VODIA, which can also be used to adjust a number of engine parameters.

Electronically controlled transmissions with a low speed option
The D9 is available with different reverse gears with straight axle and even with V-drive. All versions have electronically controlled gear shift integrated with the engine through the EVC system. Using a low speed slip option, the transmission makes it possible to creep, which is useful for maneuvering into a harbor and in trawling.
Technical data

Model D9-500 D9-575
Crankshaft power 500 hp at 2,600 rpm 575 hp at 2,500 rpm
Max. torque 1,628 Nm at 2,000 rpm 1,955 Nm at 1,700 rpm
Configuration In-line 6-cylinder diesel with turbo and charge-air cooler
Generator 115 A 115 A
Cyl. volume 9.4 l 9.4 l
Transmissions Hydraulic reverse gear and V-drive with electronically controlled shifting
Weight, excl. transmission 1,075 kg 1,075 kg
Emissions Will meet comprehensive emission requirements to be introduced in Europe and the US in 2006/2007.