Here is the list of engine specs that Norden released for the 901. There's a LOT of information to sift through here!
From the press kit:
The horizontally split crankcases allow for the engine’s large bore. They are aluminium high-pressure cast which allows for reduced wall thickness for weight optimisation, and optimised surfaces allow the engine designers more freedom in their design. The Nikasil-coated aluminium cylinders are an integral part of the sleeveless engine casing. The open-deck cylinder construction allows for optimal cooling, reduced production tolerances, and minimises the potential for cylinder warpage during production.
The 889 cc, double overhead camshaft, liquid-cooled, parallel-twin cylinder engine features the latest technology in terms of design and electronics. The maximum power output of 77 kW (105 hp) at 8000 rpm and torque of 100 Nm at 6500 rpm are outstanding figures that leave riders in no doubt of the performance potential of this state-of-the-art masterpiece. The extremely lightweight engine weighs only 53.4 kg without oil but including all components such as electric start, throttle bodies, clutch and coolant lines. Reliability, durability and efficiency are guaranteed by technical solutions such as active crankcase evacuation and a semi dry-sump lubrication which reduce oil friction and pump losses contributing to the long 15,000 km service intervals and extremely low fuel consumption, in-turn lowering the cost of ownership of this class-leading twin cylinder power plant.
- Performance → 105 hp / 100 Nm
- Long service intervals and low fuel consumption → low cost of ownership
- Cutting-edge ride-by-wire electronics → class-leading twin cylinder technology and performance
A smooth power delivery is guaranteed thanks to the state-of-the-art four-valve twin cylinder head with chain-driven camshafts and single-spark ignition. The camshafts are assembled from lightweight materials to achieve a weight advantage compared with forged camshafts, and the cam profile has been developed to create an especially torquey engine. The 37 mm steel intake and 30 mm exhaust valves with oval steel springs are actuated via DLC (diamond-like carbon) coated finger followers for minimal friction while delivering exact valve timing at higher engine speeds. The camchain is tensioned by a hydraulic chain tensioner which provides outstanding reliability.
In addition, the intake ports have been computer fluid dynamics (CFD) flow-optimised for the maximum air flow needed for high performance.
- Double overhead camshaft → compact cylinder head design, low friction and lightweight
- Flow-optimised intake ports → maximum airflow for high performance and smooth engine character
The crankshaft features a 68.8 mm stroke and runs on plain bearings to ensure high reliability and long service intervals. The rotating mass of the crankshaft has been specifically calculated for improved engine behavior at part throttle and constant speed. In addition, it is beneficial for cornering stability without compromising the agile riding character.
The plain bearing-type connecting rod links to the large-bore 90.7 mm piston at a trapezoidal (V-shaped) recess which helps reduce oscillating mass. The connecting rod bearing at the top end is bronze.
The forged pistons feature a bridged-box design with three piston rings. Due to the box construction, the piston weight is kept to a minimum while providing long durability. Additionally, the engine features two oil jets per piston for optimal cooling of the piston. Compression ratio is a high 13.5:1.
To increase comfort and reduce vibration, the engine is fitted with two balancer shafts, one in front of the crankshaft and the other in the cylinder head between the two camshafts, reducing inertia forces for a smooth ride.
- Large bore and long stroke → 90.7 mm/68.8 mm
- Forged aluminium bridged-box pistons → high performance and durability with minimal weight
- Two counter-balancer shafts and minimised oscillating masses → lower vibration
The powerful and torquey twin-cylinder engine is fitted with two 46 mm throttle bodies made by Dell´Orto. There is no mechanical linkage to the throttle grip. Instead, as the rider twists the throttle open or closed, the throttle valves are electronically controlled by the engine management system (EMS). The EMS continuously compares engine parameters with data from sensors and adjusts the throttle valves accordingly, resulting in perfect power delivery and throttle response.
To eliminate interferences between the cylinders at small throttle openings, each cylinder features a separate intake tract while a sensor in each throttle body measures and regulates the manifold pressure.
Additionally, a knock sensor on the cylinder head is fitted to detect pre-ignition or ‘knock’ in the combustion chambers – an important feature should poor quality fuel be encountered when travelling the world. The engine electronics react to vibration caused by knock by retarding the ignition and consequently protecting the engine against possible damage.
- Electronically controlled throttle → perfect power delivery and throttle response
- Active knock control → protects the engine from possible damage due to poor fuel quality
The Power Assist Slipper Clutch (PASC) maximises rear wheel grip under hard acceleration as well as preventing rear wheel instability and hopping when braking hard and coming down the gearbox into a turn, ensuring maximum control and smooth down-shifting. As the slipper clutch opens when the engine back-torque becomes too high, it prevents destabilising rear wheel chatter when braking sharply or decelerating. When the rider opens the throttle, it reduces the hand effort required at the clutch lever for changing gear and reduces lever vibration. This allows the clutch to be controlled with just the little finger, saving rider energy for extended trips and challenging conditions.
The specifically engineered friction plates provide a high friction value to increase durability and heat resistance while the steel discs guarantee sufficient oil separation for easy engagement of neutral.
PASC slipper clutch → maximum control under hard acceleration, braking and down-shifting
The engine features a six-speed sequential gearbox which ensures quick and precise gear changing due to a short shift-lever travel, light spring action and sophisticated settings of the Easy Shift feature that comes as standard.
For added confidence in challenging environments, the gearbox is linked to an Easy Shift sensor which allows the rider to make seamless up- and down-shifts without the use of the clutch. The sensor works by relaying the moment the rider actuates the gear lever to the ECU which in turn matches engine parameters to allow a simple gear change at any revs or engine load.
Based on extensive experience from Husqvarna Motorsport development, the drive sprocket features a screw-retained design as on the FR 450 Rally race engine. This allows for easier maintenance and quick gearing changes when required.
Additionally, the glass bead-blasted teeth of the fourth, fifth and sixth gears provide exceptional reliability.
The engine’s oil circulation is based on a semi-dry sump system to reduce friction losses and allow for a compact build. The compact engine provides the engineers with more freedom as to where they place the engine in the chassis, resulting in a low centre of gravity and reducing the height of the seat.
In the state-of-the-art engine, oil is actively pumped out of the crankcase, clutch housing and gearbox. An oil underpressure of 0.45 bar ensures that lubricant does not flow through the engine unnecessarily, reducing friction losses and increasing performance. The oil sump is integrated into the oil pump housing, together with two pumps (one scavenge, one supply) and a pressure regulation valve. Additionally, to maintain efficient oil temperature, the engine is equipped with a large oil cooler.
Emissions and Consumption
The Norden 901 is EURO 5 compliant: with a fuel consumption of just 4,5 litres / 100 km it combines outstanding performance with economy. It also produces just 105 g/km of CO2.