The KV6 automotive

petrol engine A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as ''E ...

has a 24-valve quad-cam V6 configuration, and a pressurising

variable-length intake manifold In internal combustion engines, a variable-length intake manifold (VLIM),variable intake manifold (VIM), or variable intake system (VIS) is an automobile internal combustion engine manifold technology. As the name implies, VLIM/VIM/VIS can vary ...

to add hot spots throughout the rev range. Variants exist in capacities. These were built initially by

Rover Group The Rover Group plc was the British vehicle manufacturing conglomerate known as "BL plc" until 1986 (formerly British Leyland), which had been a state-owned company since 1975. It initially included the Austin Rover Group car business (comprisi ...

, then by Powertrain Ltd (a sister company to

MG Rover MG Rover Group was the last domestically owned mass-production car manufacturer in the British motor industry. The company was formed when BMW sold the car-making and engine manufacturing assets of the original Rover Group to the Phoenix Cons ...

KIA Kia Corporation, commonly known as Kia (, ; formerly known as Kyungsung Precision Industry and Kia Motors Corporation), is a South Korean multinational automobile manufacturer headquartered in Seoul, South Korea. It is South Korea's second lar ...

manufactured KV6 in Korea under licence. Production moved from the UK to China in 2005, re-designated NV6.

History

First introduced into the

Rover 800 The Rover 800 series is an executive car (E-segment in Europe) range manufactured by the Austin Rover Group subsidiary of British Leyland, and its successor the Rover Group from 1986 to 1999. It was also marketed as the Sterling in the United St ...

series with the 1996 facelift, including the flagship Sterling saloon and coupe models, it has since also powered the

Rover 75 The Rover 75 is an executive car manufactured initially by the Rover Group and later by MG Rover, under the Rover marque and available over a single generation with front-wheel drive in either saloon/sedan or station wagon/estate configura ...

and its sister car, the

MG ZT The MG ZT is a car which was produced by MG Rover from 2001 to 2005. It was offered in saloon and estate versions, the latter designated as the MG ZT-T. Styling is similar to the Rover 75, upon which it was based, although various modifications, ...

, as well as the

Rover 45 The Rover 400 Series, and later the Rover 45, are a series of small family cars that were produced by the British manufacturer Rover from 1990 to 2005. The cars were co-developed as part of Rover's collaboration with Honda. The first-generation ...

and the

MG ZS The MG ZS is an automobile nameplate of MG used for two different vehicles: * MG ZS (2001), a small family car manufactured between 2001 and 2005 by MG Rover * MG ZS (crossover), a subcompact crossover manufactured since 2017 by MG Motor, a subsi ...

. The engine was designed and developed by Rover at Longbridge to replace the

Honda is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan. Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...

2.7l V6 engine which was about to become non-compliant with tightening emissions legislation. The original unit was designed for low volume production but was later redesigned to fit into the smaller

's bonnet, although performance remained similar. In 2004 the engine was licensed to

Kia Motors Kia Corporation, commonly known as Kia (, ; formerly known as Kyungsung Precision Industry and Kia Motors Corporation), is a South Korean multinational automobile manufacturer headquartered in Seoul, South Korea. It is South Korea's second lar ...

who invested in a new plant at the

Asan Bay Asan Bay is a South Korean bay in the Yellow Sea. Named after the city of Asan immediately to its south, it lies at the mouth of several rivers and separates the provinces of Gyeonggi-do and Chungcheongnam-do South Chungcheong Province ( ko, ...

complex to build the engine. This engine was used in several Kia vehicles. Its introduction in

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

shortly followed its use by Rover in the Sterling.

Applications

Gibbs Aquada The Gibbs Aquada is a high speed amphibious vehicle developed by Gibbs Sports Amphibians. It is capable of speeds over on land and on water. Rather than adding wheels to a boat design, or creating a car that floats, the Aquada was designed f ...

, a high speed amphibious vehicle *

Kia Sedona Kia Corporation, commonly known as Kia (, ; formerly known as Kyungsung Precision Industry and Kia Motors Corporation), is a South Korean multinational corporation, multinational Automotive industry, automobile manufacturer headquartered in Seo ...

(UK and North America, first generation) *

Kia Carnival The Kia Carnival ( ko, 기아 카니발) is a minivan manufactured by Kia since 1998. It is marketed globally under various nameplates — prominently as the Kia Sedona — which is now unused in favor of the Carnival. The first generat ...

(outside the UK and North America) *

Kia Credos The Kia Credos was Kia's first self developed mid-size family sedan, which went on sale in South Korea in 1995, and in Australia in 1998. The Credos is based on the fifth generation Mazda Capella/Cronos, which was sold stateside as the Mazda 62 ...

Land Rover Freelander The Land Rover Freelander is a compact luxury crossover SUV that was manufactured and marketed by Land Rover from 1997 to 2015. The second generation was sold from 2007 to 2015 in North America and the Middle East as the LR2 and in Europe as the ...

(first generation) *

MG ZS 180 The MG ZS was a sports family car that was built by MG Rover from 2001 until 2005. The ZS is essentially a tuned version of the Rover 45 (which was launched in 1999). The 45 in turn is a facelifted version of the Rover 400 which was launched ...

* MG-ZT *

Naza The Naza Group of Companies is a Malaysian business conglomerate involved in many types of business ranging from motoring to education. The group began operations in 1975 as a motor trading company. The motoring sector remains the most impo ...

Ria (Malaysia) * Rover 825 *

The NV6 variant is deployed in

Roewe 750 The Roewe 750 is an executive saloon that was produced by Roewe in China between 2006 and 2016, based on the Rover 75. Overview Launched in October 2006, and codenamed ''SAC528'' during development, the wheelbase of the Roewe 750 is stretched by ...

and

MG 7 The MG7 is a mid-size sports sedan that was built by MG Motor between 2007 and 2013, derived from its British predecessors, Rover 75 and MG ZT to suit Chinese manufacturing and sales. The name was resurrected in 2022 with the launch of the seco ...

cars (China).

Technology

At introduction, the engine enjoyed considerable technological advancement compared with its competition, most notably being the lightest and shortest V6 in its class. It has fully automatically tensioned drive belts and adaptive

Siemens Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...

EMS2000 engine management. The fuelling and ignition timing are constantly varied to match the load on the engine to improve refinement. The engine uses Variable Geometry Induction, whereby air induction pipe lengths vary to optimise engine torque in response to different engine and road speeds, aiding refinement and efficiency. Although it bears the name of K Series, the engine has almost no components in common with the

4-cylinder The engine configuration describes the fundamental operating principles by which internal combustion engines are categorized. Piston engines are often categorized by their cylinder layout, valves and camshafts. Wankel engines are often categorize ...

version. In its Rover setup, the unit delivers peak engine power of at 6,500 rpm, and maximum torque of at 4000 rpm. The automatic gearbox in V6 800s is able to communicate with the engine, briefly easing torque to allow smoother changes. A noticeable feature of the engine is its quietly growling engine note. Cam Drive The engine is fitted with four overhead camshafts driven by synchronous tooth belts. The system was a joint development between Dayco (the belt supplier) and Rover. A long serpentine belt at the front drives the coolant pump and both inlet cams. At the rear, each inlet cam drives its exhaust cam by a short link belt. The single front belt is tensioned by a spring-loaded tensioner pulley incorporating a hydraulic damping element, but the two link belts do not incorporate any tensioning device. Instead, belt tension is set at assembly by very careful control of belt length and each pulley pair is pre-tensioned. An unusual feature of this system is that it incorporates "floating" inlet cam drive pulleys that are not directly keyed to the shafts. This means that special setting tools are required to establish the cam timing before the pulley fixings are tightened. This requirement is the result of the complexity of the cam drive train. In addition to the length and thickness tolerance of the belts, the accuracy of the cam timing is also affected by the positional and diameter tolerance of each pulley and the thickness of each major engine casting. The result is that the required degree of timing accuracy could not otherwise be maintained.

Known issues

Early hand-finished units were affected by inconsistent production tolerances (1996-1998). This caused the height of the cylinder liners to vary, which risked over-compression or under-compression of the head gaskets. The engine was re-engineered and the production facility automated prior to launching the

(1998-2005), the engine having to fit under the sloping Rover 75 bonnet. Those changes resolved head gasket issues and the KV6 has a positive reputation for reliability. Most of the reliability issues relate to "value engineered" bolt on ancillaries, but the base engine is capable of large mileages before rebuild is required. The 1998 redesign of the KV6 by

under BMW included replacing the original metal inlet-manifolds and butterfly valves, with plastic units manufactured in Germany. The redesign also involved replacing the metal thermostat housing with a plastic unit. A costly but uncommon side-effect to using plastic components are breakages in the VIS ( Variable Inlet System)

butterfly valve A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. Principle of operation Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves ...

s that are mounted inside the non-serviceable inlet manifold. The second common fault is failure of the thermostat housing (often failing along the mould line), that will lead to gradual but rarely complete loss of coolant. A third common fault is oil contamination in the VIS motors that are mounted on the sides of the inlet manifold and control air intake. Damage to the butterfly valves or VIS motors is limited to causing a rattling noise in the manifold or minor loss of power at certain engine conditions. A Kia manufactured variant of the engine was also fitted to the

(people mover) with some problems on early model engines. A large percentage of first generation (1999–2005) Kia Carnivals sold in

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

required a new engine— some multiple engines. In most cases KIA provided a reconditioned short (without transmission) engine free of charge and with no questions asked, providing the vehicle was under warranty. For those outside warranty, Kia "covered costs proportional to what should have been the full expected life of components" and charged for labour and consumables.

References

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External links

A Rover 800 KV6 Coupe Owners Site. Includes Replacement of KV6 Head Gaskets!

Rover 800 Enthusiasts forum
K V6 engines Gasoline engines by model