Engines : K-Series
In taking over from the venerable A-series, Rover’s hi-tech new engine had a hard act to follow. However, it went on to earn itself an enviable reputation for fragility in both four- and six-cylinder forms.
KEITH ADAMS discusses this controversial engine…
The light fantastic
HOW to replace the irreplaceable A-series engine? Build a light, powerful and technically advanced power unit, spend years developing it to perfection; then introduce it in a highly impressive new medium sized car, quickly follow this up with a new small car which is a quantum leap ahead of the existing one. Rover employed this tactic to perfection during 1989 and 1990 – first with the Honda collaborative effort, the 200/400, then the revitalised Metro.
Austin Rover demonstrated that they were able to build a competitive and advanced engine, when they created the M16 out of the rather average O-series back in 1986. That development programme, headed by Roland Bertodo had been hamstrung by the fact that it used an existing engine as its base: with the K-series unit, the engine men started from scratch and used the opportunity to really stretch their creative impulses. Development had been started in 1984, had been placed under jeopardy by the Government of the day, who in an effort to reduce BL’s capital burden on the country’s finances.
As explained in The Whole Story, the 1983/84 BL corporate plan had required the additional borrowing of £1.5 billion in order to see through the development of the next generation of cars and their engines. £250 million of this would be swallowed up by the K-series engine development programme – and it made an appealing economy for the government to suggest that BL could in fact use a Honda engine, thereby reducing the proposed investment.
Maintaining independence from Honda
IT may have seemed like a good idea to the Government, but Ray Horrocks and Harold Musgrove certainly did not agree – both fearing that Austin Rover would have lost a great deal of their independence if they no longer produced their own mid-market engine. Musgrove was especially passionate bout this – and barracked the then trade and industry Norman Tebbitt into seeing the BL point of view: it worked – Tebbitt was persuaded and the government capitulated, allowing the continued funding of the K-series.
The company knew that in order to replace the A-Series engine, the engine would need to be both powerful and compact – and in order to achieve these goals, it would need to be highly advanced. Another consideration was that the changing tide within European legislation meant that emissions were being pushed further up the agenda and because of this, the design would need to be such that it would meet and succeed any potential new regulations. Needless to say, the company were right in this assertion and before long, lean burn engines would be all the rage – because of Austin Rover’s foresight, they were most definitely ahead of the game when the new engine appeared in 1989.
To meet these goals, the engine was constructed of alloy, and ingeniously, to ensure that the pressures within the engine were evenly distributed, a long bolt configuration was adopted. In other words, the engine was basically of a sandwich design and holding it all together were 16-inch long bolts that plunged from the cylinder head to the sump, top to bottom. Other advances were that the K-Series unit was designed from the outset to be used with a twin cam, 16-valve cylinder head; a quite exotic configuration back in 1983, but necessary in order to gain enough specific output in order to meet upcoming emissions regulations.
INTIALLY launched in 1.4-litre 16v form, the engine range was soon extended to encompass 1.1 and 1.4-litre 8v versions, which were then followed by 1.6 and 1.8-litre 16v units. This ensured that Rover would not be dependent on Honda for their mid-sized engine range and paved the way for the hot versions of the Rover 200 and MGF. With Honda power, these cars would in most likelihood been just as impressive, but less British. This power unit also formed the basis of the company’s KV6 engine (of which over 100,000 had been built by 2001) – which was used to great effect initially in the Rover 800, then the Rover 75 and MG ZT.
Like the A-series before it and also the group’s V8 engine, the K-series engine soon became the darling of the British specialist manufacturers, becoming the motive force for Caterham and Lotus.
The KV6 version of this engine was first used in the Rover 825, but it should be noted that this was a very different beast to the similarly-named power unit that would find its way into the Rover 75 and MG ZT. An insider described the earlier engine as very much a practice run, produced in an almost hand-built way – unfortunately, that led to fragility in the 825, and many power units expired before they hit the 60,000 mile mark.
When discussing the KV6 with a Longbridge engineer, Julian Donald was told of the changes: “I asked him if the cylinder head design of the KV6 was basically just ¾ of a four-cylinder engine. He said that it was on the early ones used in the 800 but that the whole engine had been redesigned for the 75 to make it narrower to fit under the shorter bonnet.”
According to Brian Gunn, other differences between the early and late K-Series engines were put in place to improve reliability: “The differences between the early and late KV6 are that the block/liners are dimensionally more accurate, with more tolerance bands. The heads are the same, although Rover changed the top covers. The inlet manifold is totally different – it does not have the dual butterfly-type throttle body like the early one. The engine management has also been changed in favour of the Siemens 2000 system over the earlier MEMS 2J system. Things like the acoustic cover have been changed in appearance, as well as detail plumbing – and other things that go with an “improvement”.
IN the 75 and MG ZT, the KV6 has proved to be a strong and sporting power unit – only over-average fuel consumption denyng it genuine greatness, but the earlier, almost handbuilt versions that found themselves under the bonnet of the 800 suffered from nightmare reliability issues – mainly with their head gaskets.
Many of the early ones were replaced under warranty at around 50,000 miles – with reliability only improving during the later years.
The K4 engine, on the other hand, seems to have become worse later in life. Early 1.1- and 1.4-litre cars seem strong and dependable, but the 1.6- and 1.8-litre cars, have developed a reputation for eating head gaskets, sometimes as early as 18,000 miles. Although the company claimed to have fixed the problem at several times during the production run – some blame the plastic dowels used in its construction, others flaws in the design of the cooling system – owners of 2000-2005 cars were still regularly suffering regular head gasket failure.
Such was the extent of the problem, it was highlighted on BBC TV’s Watchdog programme – and an MG Rover representative’s dismissive stance on the show shocked many existing customers, and scared off future ones.
Today, the K-Series engine has been heavily tarnished by its reputation for fragility, and although there are many more satisfied than dissatisfied customers out there, once an image is established, it’s fate is sealed.
The real shame of it is, the K-Series engine remains an impressive design to this day. And with it, Rover proved it could maintained the ability to produce its own power unit, and with that, maintain their independence and identity. It’s just a pity that this light and efficient engine wasn’t allowed to escape from the shadow of unreliability, because if it had, we’d still be marvelling its huge armoury of positive points to this day…
Specifications & applications
|Capacity||Bore||Stroke||Type||Max. Power||Max. Torque||Applications|
|1120cc||8v||60Ps @ 5700rpm||90Nm @ 3900rpm||1995-1998: Rover 100|
|16v||75Ps @ 6000rpm||95Nm @ 5000rpm||1999-date: Rover 25|
|1396cc||75mm||79mm||8v SPi||75Ps @ 5500rpm||117Nm @ 4000rpm||1990-95: Rover Metro GTa
1995-98: Rover 100
1990-96: Rover 214i
|16v||84Ps @ 6000rpm||110Nm @ 4500rpm||1999-date: Rover 25|
|16v MPi||95Ps @ 6000rpm||1989-95: Rover 214 / Rover 414
1990-95: Rover Metro GTi
|16v MPi||103Ps @ 6000rpm||123Nm @ 4500rpm||1995-99: Rover 214 / Rover 414
1999-date: Rover 25 / Rover 45
2001-date: MG ZR 105
|1589cc||16v MPi||109Ps @ 6000rpm||138Nm @ 4500rpm||1995-99: Rover 216 / Rover 416
1999-date: Rover 25 / Rover 45
|16v||116Ps @ 6250rpm||145Nm @ 4700rpm||2002-date: MG TF 115
2003-date: MG ZS 115
|1796cc||80.0mm||89.3mm||16v||117Ps @ 5500rpm||160Nm @ 2750rpm||1999-date: Rover 45
2001-date: MG ZR 120 / ZS 120
|16v||120Ps @ 5500rpm||160Nm @ 4000rpm||1999-date: Rover 75
2003-date: MG ZT 120
|16v||120Ps @ 5500rpm||165Nm @ 3000rpm||1995-2002: MG F 1.8i/1.8i Stepspeed
2002-date: MG TF 120 Stepspeed
|16v||136Ps @ 6750rpm||165Nm @ 5000rpm||2002-date: MG TF 135|
|16v VVC||145Ps @ 6900rpm||173Nm @ 4500rpm||1995-99: Rover 200 Vi|
|16v VVC||145Ps @ 7000rpm||174Nm @ 4500rpm||1995-1999: Rover 200 Coupe|
|16v VVC||145Ps @ 6750rpm||174Nm @ 4000rpm||1998: Rover 200 BRM|
|16v VVC||145Ps @ 7000rpm||174Nm @ 4500rpm||1995-2002: MG F 1.8i VVC|
|16v Turbo||150Ps @ xx00rpm||215Nm @ 2100rpm||2002-date: Rover 75 1.8T|
|16v VVC||160Ps @ 6900rpm||174Nm @ 4700rpm||2001-2002: MG F Trophy 160 SE
2002-date: MG TF 160
|16v VVC||160Ps @ 7000rpm||174Nm @ 4500rpm||2001-date: MG ZR 160|
|16v Turbo||160Ps @ 5500rpm||215Nm @ 2100rpm||2002-date: MG ZT/ZT-T 160 1.8T|
|1997cc||24v KV6||150Ps @ 6500rpm||185Nm @ 4000rpm||1999-date: Rover 45
1999-date: Rover 75
|2497cc||24v KV6||160Ps @ 6250rpm||230Nm @ 4000rpm||2001-date: MG ZT/ZT-T 160|
|24v KV6||177Ps @ 6500rpm||240Nm @ 4000rpm||1996-1999: Rover 825
1999-date: Rover 75
2001-date: MG ZS 180
|24v KV6||190Ps @ 6500rpm||245Nm @ 4000rpm||2001-date: MG ZT/ZT-T 190|