As part of our Rover SD1 at 40 special, here’s what Leyland Cars’ Director of Engineering and Product Planning, Spen King, had to say on the subject. This article is taken from the British Leyland Mirror, 30 June 1976.
Spen King (second from left) outlines the engineering philosophy behind the Rover 3500
The one word, simplicity, encapsulates the engineering philosophy of the new Rover 3500, a philosophy conceived by Spen King, Leyland Cars’ Director of Engineering and Product Planning. The car is the second, new-generation Rover for which Spen King and his team have been responsible. The first was the 2000 series.
Yet, despite the different approach, comparitive complexity in the 2000, refined simplicity in the 3500, the new car is solidly in the finest Rover tradition. But that tradition has not prevented the team’s engineering philosophy from evolving quite radically in some areas.
Said Spen King: ‘We have learned a great deal about design and development, particularly with regard to the fundamental engineering axiom that the best solution to a design problem is the simplest, all other factors being equal. The key to that statement is: how do you get the other factors to be equal, or how do you achieve extremely high standards of performance without using complex or costly mechanisms or structures?
‘We found the answer in a strictly disciplined development and refinement programme. This meant, then, that we consciously avoided over-complicated structures. We minimised the number of components in the suspension. We simplified all design aspects as far as possible and then we refined and refined again until we have what we believe is a superb end product.
‘It is easy to appreciate the economic sense of this approach. It minimises tooling charges, cuts production costs and reduces the number working and hence wearing parts of the car, thus reducing the frequency and cost of service replacements.’
Using advanced computer techniques the Engineering Team evolved an integral construction body which surpasses any previous designs in terms of safety and integrity but which is simpler to produce than its predecessors. Long-term durability was the next priority. A tremendous amount of engineering time was invested in all aspects of anti-corrosion protection, even to the extent of force ventilating some of the box sections to prevent a build up of corrosive damp, as well as the use of zinc coated panels.
One of the cars biggest surprises is the simplicity of the suspension layout with MacPherson struts at the front and a new variation on the live-axle theme at the rear.
Added Spen King: ‘By using very carefully developed geometry and self-levelling rear damper units, we think we have achieved a better combination of ride and handling than in any other product in the new Rover’s class.’
The superb light-alloy V8 engine is familiar to everyone with an interest in the motor car. It has established a fine reputation for power and reliability. But the Engineers decided to improve it even further. It is now a freer revving unit going up to a maximum 6000rpm from the original 5200rpm with a consequent extension of the power and torque curve.
He said: ‘Some people may well compare the new Rover with the old 2000 series and say that it is not so technical in its specification. This is absolutely true and it is quite deliberate. With the 2000, in an age when people set great store by impressive specification, Engineers enjoyed themselves using quite complex solutions to achieve the design requirements. On this car we had to use much more subtly and more intensive development to get equally impressive results from a simpler design which would offer easier servicing, better reliability and generally better cost-effectiveness.’
On all aspects of our design work we had to remember the need to get the quality and safety we wanted without excessive weight or cost which would affect performance, economy and value. It wasn’t an easy job, but we are pleased with the results.’