Special K

The wider background to the K-series roots was an increasing awareness at the European Union of exhaust emissions and their harmful effects on health and smog. High power output, small-capacity engines looked like a path to achieving higher efficiency and low emissions. This implied four valve per cylinder configurations for better engine breathing and aluminium construction to save weight.

This was exactly what BL Technology’s engineers had been researching with the 973cc ECV3 three-pot (there was also a 1.4-litre four-cylinder). Mixture swirl and tumble gave more complete combustion and the team was able to lean off the mixture strength at part-throttle conditions from air/fuel mixtures of 14.7:1 (or stoichiometric) to as lean as 20:1, a technique which was becoming known as ‘Lean Burn’. Ultimately BL, like Lotus, could see the inkling of a possibility of a compression ignition system for the petrol engine, such as that used today by Mazda in its Skyactiv units.

But the most favoured solution to exhaust emissions at the EU level was the exhaust catalyst, already in use in the USA and seen as a way of dealing with hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NOx) emitted from car exhausts. Lean burn, while efficient, can’t do as much as a catalyst to scrub the exhaust of these pollutants and worse, through the effect of increasing the temperature of combustion, lean burn can encourage the dissociation of nitrogen in the air with oxygen to create NOx, which is associated with city air smog, breathing difficulties and the creation and worsening of conditions such as asthma.

At the same time, the role of Tetraethyllead in fuel was coming under increasing scrutiny in the UK and Europe. As well as being a toxic nerve poison, lead also coats the surfaces of an exhaust catalyst drastically reducing its effectiveness. Lead was on its way out seemingly to pave the way for exhaust catalysts, though it took until the late 1990s for the last leaded petrol burning cars to be outlawed.

These issues (lean burn versus catalysts, leaded versus lead-free petrol and, ultimately, diesel versus petrol) were complicated and difficult to understand and unify, not least for politicians who tend to be technically illiterate and also were polarised in their views of maintaining their stake in Britain’s last remaining mass car maker.

As for British Leyland itself, by the end of the Michael Edwardes era in 1982, his preferred British Leyland structure had been signed off by Patrick Jenkin MP, industry secretary. With Canley, Abingdon, Speke and Solihull closed, BL’s total car production had a likely ceiling of three quarters of a million out of Cowley and Longbridge, which was a far cry from its heyday, but compact enough to be attractive to bigger rivals.

The structure consisted of two main divisions, the Land Rover/Leyland group (Land Rover was still seen as a commercial vehicle operation) and the Cars Group under Ray Horrocks. Horrocks’ empire consisted of Unipart, Jaguar (eventually under John Egan) and ARG holdings under Harold Musgrove, which was basically Triumph and Austin Rover. The structure was criticised at the time by industry observers as being unwieldy and by the trade unions as being a precursor to privatisation (both turned out to be true).

The collaboration with Honda on the Rover SD1 and Triumph Acclaim replacements were starting to make waves, however. Local content agreements in the EU consisted of only a ‘gentlemen’s agreement’ in France, and both Renault and Peugeot-Citroën were starting to get antsy about Austin Rover’s work with Honda.

Conscious of these gathering storm clouds over Japanese content (as well as Austin Rover’s identity as an independent car maker), BL’s 1984 corporate plan calculated the Treasury would have to supply an additional £1.5 billion of new car development budget with £250 million of that devoted to the K-series. It was Musgrove who fought tooth and nail for the engine, despite UK Government demands that Rover use Honda or Peugeot engines instead.

In fact, at several points the Government decreed that all development activity should cease at BL, one engineer telling me that he and several others had physically removed prototype engines (I think from Gaydon), which had been headed for the scrap bin, taken them home to hide in their sheds and bringing them back several weeks later when the switcheroo decision on research and development had changed direction once again.

Through this political maze, Horrocks and Musgrove played their cards brilliantly, profoundly understanding the Government’s reluctance to bankroll a new engine, but also its antipathy towards EU diktats. Musgrove sold the idea of lean burn to Norman Tebbit, one of the largest critics of this state-owned car maker, and if lean burn were to succeed, it would need a new engine.

‘It was K-series or me,’ Musgrove told a former colleague over lunch a couple of years ago. Margaret Thatcher went into bat for lean burn, for it was a useful cudgel with which she could beat the eurocrats. The fact that lean burn lost out didn’t really matter, although when it appeared, the K-series was a less efficient device than it could have been thanks to exhaust catalysts of the era requiring a constant diet of 14.7:1 air fuel mix to work properly.

For Hiljemark, none of this was evident from the coal face of engine development. ‘That budget was not a real question,’ he says. ‘I started with about 50 engineers but I was able to recruit anyone I wanted. I went to Ford, Lotus and Ricardo to hire really good, clever engineers.’

He says that while Ford and several others were interested in buying the company, from his position it was a case of press on regardless. And so they did: the early K-series was a top-hung wet-liner engine made of four major castings: a ladder-style casting with the upper cam bearings which the cam cover attaches to; the cylinder head with the lower cam bearing on top; the block; and a racing-type deep-sided ladder, which has the bottom main bearings cast-in and onto which the sump attaches.

The block and head were made of heat-treated L25 aluminium, a good strong corrosion resistant casting material in widespread use in the automotive industry and the bearing carriers were LM24, an alloy well suited to pressure die casting. The whole assembly was bolted together with ten 412mm long bolts, which were relatively loosely torqued so the greater expansion of aluminium locked the assembly together when hot.

On initial pre-production engines the bolts were exposed, but Hiljemark wanted them to be covered with material and part of the construction, which gave the engine a ‘cleaner’ appearance and also provided a series of vertical oil ways through which the lubricant could drain down to the sump.

It was a stiff little engine of a high specification, able to rev at 6500rpm for long periods. But like all advanced engines, you needed to look after it and those early head-gaskets were arguably under-specified, with the later Multi-Layer-Steel gaskets developed by BL Powertrain with Lotus a better sealing solution. And like all aluminium engines if it got too hot the casting material became annealed, which reduced strength and the head could warp, opening a gate into a wild wood of new horrors. The other point is that it was designed as a small capacity unit and subsequent swept volume increase and massive power increases arguably stretched this thin-wall concept beyond breaking point.

Marketing pushed for a 1.6-litre unit, though, which Hiljemark was against, ‘but eventually I said yes’. And gradually the specification of the engine was reduced with more plastic components, which didn’t give the high fixing tolerances the unit required. So is Hiljemark still proud of it? ‘Yes, I am,’ he says. ‘Of course, some have pointed to the quality problems, but much of that was the fault of cost savings. The K-series is a fantastic engine.’

Keith Adams, editor of Parkers and the excellent if poignant website AROnline, which documents the sorry tale of BMC, British Leyland and all who sailed in them, is equally enthusiastic. ‘It’s a brilliant little thing, it really was,’ he says. ‘It was a different tale with the 1.6-litre version and in the Phoenix era where the cheapening process meant that reliability was leaking away year after year, but those initial engines with their sandwich construction were works of art and in 1.4-litre form it was a much better engine than the 1.6-litre Honda alternative. From a classic point of view, it makes all kinds of sense, with all the parts available.’

In the end history hasn’t been very kind to the K-series, but I think that’s unfair. When it was launched there was literally nothing out there like it, and its subsequent reliability issues said more about what it had been asked to do, and the general careless neglect which seems a key part of main dealer servicing these days, than any inherent fault in its original design. Looked after, serviced properly with regular checks on coolant levels, a K-series will prove a loyal servant and many have run well into six-figure mileages.

Ignore that, however (and many have), and you won’t have to go looking for trouble. It will find you all by itself.