Volvo’s new S80 – luxury, V8 Power, AWD Poise

“A compact format is a matter of safety,” explains Crabb. “It is particularly important that the engine takes up minimal space longitudinally in the vehicle. Volvo’s engines are fitted transversely and a compact engine thus has more space to move inside the engine compartment in the event of an impact that deforms the car’s front. This helps reduce the risk of engine penetration into the passenger compartment.”

The engine itself cannot be made all that much smaller since the cylinder spacing and block structure are roughly the same as in the five-cylinder engine. Instead, the focus was on building the entire installation, encompassing the engine, automatic transmission and ancillaries, in as compact a package as possible. One additional condition that had to be taken into account was that the transmission would be a six-speed automatic.

The compact dimensions of the transversely mounted, inline six-cylinder engine are ensured by locating the ancillaries, such as the power-assisted steering pump and air conditioning compressor behind the engine in the space above the gearbox.

Consequently, there is no front-end drive of the ancillaries. Instead they are driven via gears by the rear end of the crankshaft. This engineering solution is known as READ – Rear End Ancillary Drive.

The alternator is directly driven and installed on the engine block. This solution means that the entire engine and transmission package takes up minimum space, particularly in the car’s longitudinal direction.

By designing the drive system in the form of a small gearbox with an intermediate shaft inside the driveshaft – known as a Shaft-In-Shaft design – it was possible to ensure a very short package. The two shafts are driven by different gears that give them different speeds (one speed for camshaft drive and one for the ancillaries).

“We are very proud of this compact solution,” relates Crabb. “A lot of highly advanced development work was required in order to arrive at a design that ensures smooth and quiet operation.”

The vibration damper too, which compensates for vibration in the six-cylinder engine’s relatively long crankshaft, has been moved inside the engine block. The IVD (Internal Viscous Damper) is of the fluid type and is an unusual solution in the context of passenger cars.

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