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Essay : Rover 75 revisited

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August 7, 2011 · Keith Adams · 2 Comments

What would Rover produced during the 1990s without Honda or BMW to influence the situation?

Inspired by Roy Axe’s AR18 prototype photos, AROnline‘s very own engineering genius Robert Leitch cooks up an enticing recipe for Rover’s 1990s’ growth…

Words: Robert Leitch

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Doing it Rover’s way…

THE APPEARANCE of those previously unseen Rover 700 pictures made me think, not for the first time, what sort of car Rover might have made to succeed the 600 and 800 without the intercession of BMW, or the legacy of Honda. Briefly, our scenario is that in 1994, Rover have said their last sayonara to former partner Honda. Either British Aerospace, or a new non-carmaker master is funding a replacement for the 600 and 800, which will share the same platform and major components and free the company of expensively licensed Honda heritage.

Even without a very limited project budget this is possibly the hardest challenge the firm’s designers face as they are entering a fiercely fought sector with some excellent competitors.

How big?

	Wheelbase	Front track	Rear track	Length	Width	Height	Weight (kg)	Model
Rover 75	2745	1505	1505	4745	1778	1427	1425	2.0KV6
Rover 620	2727	1475	1480	4645	1715	1380	1255	620Si
Rover 820 R17	2770	1483	1450	4880	1730	1397	1408	820Si
BMW 3-Series (E46)	2725	1481	1493	4471	1739	1415	1360	318i
BMW 5-Series (E39)	2830	1516	1530	4775	1800	1435	1496	520i
Mondeo MkII	2754	1522	1537	4731	1812	1429	1301	2.0LX
Mondeo MkI	2704	1503	1487	4556	1745	1372	1322	2.0LX

The table above shows the dimensions of the ‘BMW’ 75 compared with its predecessors and competitors. In a decade the ‘footprint’ of the mid-size class has grown so large that the 1986 Rover 800 is now scarcely larger than a Mondeo. The closeness of the principal dimensions of the ‘BMW’ Rover 75 to I the 800 bears out the notion that an R17-based predecessor set the dimensions of the design which reached production.

What is notable is how little separates them – around 45mm in track, and around 66mm in wheelbase, excepting the ‘one class up’ BMW 5-Series. That car is included as it points to how a larger Rover 900 could be derived from the same platform.

The dimensions our notional cars would be:

	Wheelbase	Front track	Rear track	Length	Width	Height	Weight (kg)	Model
Rover 700	2750	1525	1525	4650	1750	1430	1400	733 Vitesse 230T
Rover 900	2900	1525	1525	4800	1800	1450	1490	932 V6 Sterling

The ‘dual identity’ of the two cars dictates a width in the upper range, otherwise the dimensions would not deviate beyond the Mondeo territory for the 700. Market placement demands a piece of legerdemain, to build down to Mondeo/Vectra prices while having distinctive enough character and engineering to compete with the BMW 3- and 5-Series and Audi A4 and A6 on their own terms.

Powertrains

The foremost weakness of the Rover 75 was the engine line up – four engines which, each in their own way, fell short of what was expected of them.

1.8 K-Series. Struggled to haul around a car 250kg heavier than Rover’s next heaviest passenger car application, the HH-R 400. The sluggishness might have been bearable in the light of the car’s ‘relaxed’ ethos, but premature engine failures were not. The MGR-era turbocharged version addressed the former weakness and hastened the latter.

2.0 and 2.5 KV6. An answer to a question nobody asked. The 2.5 is almost big enough to make its case, but 2.0 litre buyers saw ‘turbine-like smoothness’ as no compensation for a fragile, thirsty, expensive to maintain engine.

BMW M47 diesel. Considered the best choice at the time, but unloved by those who make their living tending to the needs of middle-aged and elderly BMWs

Ford V8. Enormously appealing but ultimately irrelevant. The heart may yearn, the head will go for a BMW 330d.

My answer to this is a new home-grown engine line which covers most of the above territory. I’d call it the U, or Universal series, not just in compliance with alphabetical sequence, but also to demonstrate its versatility. The new engine would use the T-Series and L-Series cylinder heads, combined with a new block emancipated at last from the dictates of the ADO17 gearbox. Using the existing heads would set the cylinder centres closer than an ideal size, but would save on tooling – the budget for the exercise would be around £250 million.

The new block would have a longer crank than the T-Series and eliminate the offset con-rods which had been a family characteristic since the O series. Wider bearings would therefore be possible. The new cast-iron bottom end would be dimensioned to accommodate a 100mm stroke, to allow a maximum capacity of 2250cc, and would incorporate contra-rotating balance shafts for the larger capacity versions.

A variable valve timing system would be introduced for the upper-level versions, a simple cam-phasing arrangement rather than the complex variable duration K-Series VVC system. The intention would not be to create an 8000rpm screamer, but to optimise breathing across the normal rev range giving smooth running, and torque delivery at low engine speeds without the compromise of the engine being starved of air flow at high revolutions, thereby robbing the driver of the full benefit of the engine’s cylinder capacity and valve area. As well as increasing power, the system would reduce fuel consumption and emissions.

The U series range could encompass everything from a basic but competitive 16V entry level 1.8 litre to a turbocharged 2.2 with an output close to the Ford V8 in the ZT 260.

U-4 1.8 16v – 125bhp
U-4 2.0 16V – 140bhp
U-4 2.0 VVT 16V – 160 bhp
U-4 2.2 VVT 16V – 175bhp
U-4 2.0 16V Turbo – 190bhp
U-4 2.2 16V VVT Turbo – 230bhp

U-4 1.8 Diesel – 85 / 100bhp
U-4 2.0 Diesel – 95 / 110bhp
U-4 2.2 Diesel – 110 / 125bhp

Although these cover about 90% of the market’s needs, there would still be a place for a larger, multi cylinder option. Imagining for a moment that the men from Kia had not turned up one day on Rover’s doorstep with several suitcases full of Won, and the KV6 was consigned to the roster of ‘engines that might have been’, a bought-in V6 would be the logical option. GM, Ford, Alfa Romeo, VW, or Peugeot could well have been delighted to sell a few more petrol V6s – even in the mid-’90s they were not a popular option.

Another possibility would be a home-grown U-5, which could also serve in place of the Land Rover TD-5. This would favour the wide track approach, but was perfectly feasible technically and in market acceptability, as Volvo were already demonstrating with the well-regarded and successful 850.

The question of which end should be driven is, at first glance, wide open. A move to rear wheel drive has strong appeal, allowing a wider range of engines to be accommodated, and affirming an aspiration to BMW and Mercedes Benz territory. However the need to share parts with the smaller Rovers, and the time required to develop a new RWD chassis, with nothing in the range as a starting point, would dictate front wheel drive as the cost and time effective choice. The key to the project is evolution – build on what had been produced previously rather than starting anew.

Transmissions are an easy enough matter. Breaking the ‘no-Honda parts’ rule just for once, I’d go for the PG1 gearbox for the lower powered versions, with the Chrysler gearbox used in the 825D for the most powerful diesels. By the mid-’90s the choice of suitable proprietary automatics was considerable. Choose with care from the offerings of ZF, Jatco, or Aisin.

Chassis

Here there is but one way to go – a full Hydragas set up updated for the 21st century, retaining the classic double wishbones and trailing arms, but also enhanced by self levelling and active damping control, to give a ride and handling experience only Citröen could come close to matching.

That’s the dream. Regrettably the new car was entering a world almost as cynical as the one we now inhabit, where suspension does not sell cars – NCAP ratings, ECE fuel consumption figures, CO2 tax breaks and litanies of largely un-necessary equipment and technology do. Therefore we shall go to the opposite extreme, and opt for a scaled up version of the R3 200’s MacPherson strut/torsion beam set-up. Remember this is happening a few years before the Focus’s control blade rear suspension challenged the torsion beam orthodoxy. Rover had been saddled with complicated Honda suspensions which promised far more than they delivered, and a return to LC10-era simplicity would stand a chance of delivering acceptable results at low cost.

Body Engineering

Once more we face the dichotomy of the idealistic and acceptable realism. It would be wonderful to bring the ideas embodied in Spen King and Gordon Bashford’s ECV3 to production reality to produce something far lighter and more efficient than the competition. Again constraints of time, money, and a far less adventurous and individualistic customer base would dictate a conventional steel monocoque, possibly taking the ‘soft presses’ idea used successfully for the R8 derivatives forward in concert with aluminium and plastic panels to allow variants and facelifts to be achieved at low cost.

Building in a greater than normal degree of adaptability into the body design and tooling would be high on the wish list. It is notable that around the same time as the ‘BMW’ 75 appeared, Fiat were making much of the ‘spaceframe’ construction of their new Multipla, which allowed substantially different body variants to be engineered at a fraction of the cost of a traditional monocoque. Little has been heard of the idea since.

The long wheelbase flagship car could provide the better opportunity for adventures in aluminium, anticipating the road on which Jaguar were about to embark.

Body variations would be the lifeblood of the new car – by the end of the 20th century it was unthinkable to offer one body style. A four/five-seat saloon would be a given, but why not pair it with a close coupled four-seat, four-door fastback. The obvious second bodystyle would be an estate car – the ‘BMW’ 75 wagon nearly never happened, but was one of the rare success stories of the MGR era. Rather than the obvious coupe or convertible, there could be more profit in seizing the Zeitgeist with a high riding Volvo XC style estate, or even a luxury seven seat MPV – imagine a better looking Subaru Tribeca.

Rover would remain the core brand, but with no in house competition from Honda or BMW, there would be a strong case for reviving the Triumph identity, or producing MG versions. My own pet idea, never attempted even in the MGR era, would be an honest-to-goodness Morris Oxford, in saloon and estate car versions, as a sort of proto-Skoda Superb.

Finding a style

Imagine yourself as a technologically aware 35-year old, in possession of a modest fortune, and approaching the peak of your career. The truth universally acknowledged is that you will be in the market for one of the aspirational mid liners which are our new Rover’s rivals. Do you see yourself surrounded by sitting on over stuffed chairs, facing swathes of veneer and instruments evoking 1930s radio set designs, in an evocation of a gentleman’s club ambience rendered absurd by a television screen at its centre, and a buttock-sized airbag in the steering wheel boss?

Of course you don’t. You’re looking for a cool, minimalist, ergonomic driving environment, of exactly the sort which the 1963 Rover P6 introduced to a startled world and initiated a design progression which continued through to the SD1 and XX.

For once it’s surprisingly easy to pinpoint where it did all go wrong – the sequence of events which led to the ‘BMW’ 75 started with the airbrushing of the P6 and SD1 from Rover’s history in favour of the 1959 P5 Three Litre. That car was overweight, underpowered, grew too big and heavy to replace the P4 as was intended, and failed to match its predecessor’s legendary refinement and quality and certainly not the audacious radicalism of its design. The P5’s afterlife status as a signifier of a certain type of British identity has more to do with its association with royalty and the top tier of government than its engineering or general competence.

The P5s exterior and interior styling is rightly admired as a snapshot of a bygone age, but doomed it to be a marginal product in an era when the market wanted drivers cars, like the Jaguar Mk2, rather than gentleman’s carriages. By the early-’60s a strengthening economy and wider availability of tertiary education saw Britain’s professional and managerial class growing in number and becoming ever younger and more ambitious – these were not people prepared to wait to step into dead mens’ shoes.

Thankfully by the time the P5 went on sale, the Rover Company had released the safety catches on their own young guns, and showed they knew exactly what was wanted with the P6. The parallel with the 1998 75 is clear. Until the R17, the Honda-era Rover design vocabulary had a clear lineage back to the SD1 and P6 – with the wedge/fastback interplay, proudly grille-less noses, floating roofs and flush glazing. The XX interior is more like an evolution of the P6 than the SD1′s was. Like the P6 and SD1, the aesthetic of the XX, R8, and the doomed AR6 was rational, minimal and forward looking.

Move forward to the early ‘90s and the signs were that the customers rather liked the new style which arrived with the R17 – witness the eventual adoption of the chrome grille across the R8 range. In retrospect it’s a pity that Rover fell into that particularly narrow trough of design identity, from which only the MGR-era MG offerings represented any sort of escape. What was desperately needed for the new range-topper was an ‘XF moment’ a convincing break from a referential aesthetic which had no place left to go but up its own fundament. Other manufacturers were unhealthily bound to their past – Jaguar and Saab spring to mind, but elsewhere there was positive design progression particularly at Volvo, and to a lesser extent in the Alfa Romeo 156 and 147. Jaguar have – fingers crossed – set themselves free in two bounds. The jury is out on Saab.

I have looked at the possibilities, and tempered them with reality. The budget for any new medium/large Rover would inevitably be a fraction of that of a new Audi A4 or BMW 3-Series, and there is a huge risk that these constraints would result in a product offering no obvious advantage over its mass market rivals. Notwithstanding this, I think it would have been a job worth doing – one of the industry’s toughest challenges. With bulletproof mechanicals, a ‘bespoke’ approach to range options and development, and exterior and interior design with wide appeal, we could even have seen a true British Rover once more.

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