Unsung Heroes: Montego Turbo Diesel
Mike Humble takes a sideways look at one of the sheds that littered the highways and by-ways of the UK. The Montego might have been a little tired by 1989, but the addition of a turbodiesel breathed new life into it.
And for Mike Humble, that record breaking economy and unburstability should be celebrated.
New Light Through Old Windows
Now I know for a fact that many people out there will be either laughing or shaking their heads at the thought of a diesel Montego being described as a ‘hero’. But, I ask for a bit of hush and to bear with me as I try to decipher the reasons why the utterly average Montego Diesel rates as being a past master in its field.
I have often regarded the Montego as Austin Rover’s turning point. Where a slim profit was almost within grasp, by throwing away BL traditions of grease nipples and displacers à la Ital or Maxi and replacing them with high technology cars and innovative ideas, which even made Ford sit up and rub its eyes. Soon after launch however, it became obvious that the Montego was not the super car ARG hoped it would be. The launch of the MG Turbo in 1985 picked up morale somewhat, but in all fairness, the Montego was left to soldier on with only very minor revisions until it’s major re-vamp for the 1989 model year.
Since 1986, the Maestro van had been available with the Austin Rover MDi/Perkins Prima 2.0 diesel which was one of the first high speed direct injection for use in a van (the Fiat Croma beat it into car production, though). Perkins, a world leader in diesel technology. It built the engine in kit form in Peterborough, with raw castings such as the engine block, crank and cylinder head coming from Longbridge.
The engine was based on the 2.0-litre O-Series unit and shared its bore/stroke as well as having a visual similarity, but here was where the comparisons ended. The Prima had an amazingly rigid crankcase and strong cylinder block resulting in a low mortality rate. Even in hard use, Perkins really tested and developed these engines to the hilt.
In standard naturally-aspirated form, the Prima developed an average sounding 60bhp but also had a torque curve that started to peak just a few hundred rpm above idle speed. Fuel economy was outstanding – with mpg figures in the high 50s even in a van, the engine was well within it’s design limitations and developers were soon testing turbo versions in secret.
Plans had been afoot for some time regarding a new diesel engine. The only small BL diesel was a derivative of the 1800cc B-Series – and as we know the petrol unit gave way to the O-Series in 1978. And that resulted in the new diesel having a direct bloodline with BMC.
The Montego was fighting its corner in the most aggressive sector. In the mid-’80s, diesel cars were still pretty much the mainstay of taxi fleets – company car drivers would still pound the tarmac with petrol vehicles. But sales of diesels were slowly gathering momentum and Austin Rover – for once it seemed – was on top of the situation with plans in hand for a mid-range diesel car. With revisions to its fueling systems (using a Bosch fuel pump over the traditional C.A.V system) and Garrett turbocharger, the MDi/Prima now developed 80bhp along with an improved torque curve.
In one fell swoop, Austin Rover now had a superb low-cost engine to fit the needs of not only the car range of Maestro/Montego but also Freight Rover with this engine being ideal for the 200 series van. The 1988 motor show was a big event for ARG – now simply named The Rover Group – with a range of improved Maestro/Montegos now sporting diesels and turbo diesels.
The main recipient of this engine was the Montego. For the ’89 model year it sported a revised dash with updated heater controls, clocks, seats, gearboxes and engine management systems – and of course, a turbo diesel. Rover was now back in private ownership being now owned by BAe – and considerable attention was given to quality and branding. It now seemed that Rover could almost, just almost, be a viable long term winner.
Morale at both Longbridge and Cowley was at an all time high. Thanks in part to a good pricing structure, low servicing requirements and class leading fuel economy, the Montego turbo diesel was an instant hit with the public and of course, the motoring journalists.
What Car? magazine named the Montego Turbo Diesel as its family car of the year; quite amazing considering by this time the range was viewed by many as being staid and tired – certainly when compared to the Cavalier and Sierra. Fleet companies were keen to get into the Montego Diesel as no rival could offer 12,000 mile servicing intervals and a cam belt change requirement of an unbelievable 70,000 miles. Even more staggering was the fuel consumption – the Montego Diesel would achieve over 60mpg at 56mph. This was not only class leading, but also a World Record. And Rover wrung the most publicity out of this fantastic engine by doing an AA sponsored economy run gaining over 100 mpg – none too shabby even by today’s standards.
Obviously, with only 80bhp on tap, performance was at best described as average and certainly quicker than the 1.6-litre Cavalier or Peugeot powered Sierra. Early models suffered from gearing that was slightly too high for the engine but Rover saw wise to cure this by altering the final drive and closing the ratios – thus giving much better in gear acceleration while still offering a relaxed top gear for cruising.
At the same time, Perkins engineers with help from Bosch developed clever two stage injectors which drastically reduced the loud diesel ‘crackle’ under heavy engine load. This gave the Montego a quieter drive both in and outside the car. The principle behind this improvement was due to fuel was injected softly at the start of the combustion cycle followed by a high pressure burst to complete the power stroke. Exhaust gas recirculation (EGR) also became a standard fit helping to reduce the smoke under turbo boost, a visual effect which the Montego became famous for.
Soon after introduction, sales of the Montego soared both in the company and private sector. The most popular model was the carvernous estate in LX trim, and often specified with power steering – the Montego diesel was a difficult car to manoever at parking speeds.
So in all, the Montego was given a healthy boost by the fitment of this engine. Costs were low, thanks to collaboration with Perkins and – above all – the engine was reliable with recorded mileages in excess of 300,000 miles being regularly noted. The Montego Turbo Diesel officially died in 1995, but the spirit of this engine lived on for another 10 years in the form of the L-Series which was a major re-work of the Rover/Perkins unit.