Editing Rover K-series engine (section)

==Design history==
[[File:KseriesK18.jpg|thumb|right|The cylinder block of a United Kingdom Rover K-series 16-valve DOHC engine with ''damp liner'' cylinders]]
The K series was introduced in 1988 by [[Rover Group]] as a powerplant for the [[Rover 200 / 25|Rover 200]] car. It was the second volume-production implementation of the low-pressure sand-casting (or LPS) technique in a new plant sited between East Works and [[Cofton Hackett]]. (The first volume application of the LPS process had been for the [[Rover M-series engine|M-16]] cylinder head, produced in South Works, adjacent to the former forge). The LPS process pumped liquid aluminium into a chemically-bonded sand mould from below. This reduced oxide inclusions and gave a casting yield of around 90%, compared with 60% for more conventional gravity casting processes. The process avoided many of the inherent problems of casting aluminium components and consequently permitted lower casting wall thickness and higher strength-to-weight ratios. However, the process required the use of heat-treated LM25 material which gave the engines a reputation for being fragile. An engine overheat would often result in the material becoming annealed and rendering the components scrap. The layout of the engine bay on some Rover cars fitted with K-series engines – particularly the MGF with its mid-engined layout – means that a commonly-occurring coolant leak under the inlet manifold can go undetected until severe damage has been done to the head. The aluminium engine blocks were fitted with [[centrifugal casting (industrial)|spun-cast]] iron [[cylinder liner]]s that were initially manufactured by [[GKN]]'s Sheepbridge Stokes of [[Chesterfield, Derbyshire|Chesterfield]], but these were replaced by liners made by Goetze. Unfortunately a large number of aftermarket engines, the so-called "VHPDs", were built with the old substandard GKN liners by Minister, Lotus and PTP well after the introduction of the Goetze liners to production in 2000.

The engine was introduced initially in 1.1-litre [[single overhead cam]] and 1.4-litre [[dual overhead cam]] versions. Because Honda stopped providing Rover with engines after the end of their relationship, but well before the BMW takeover, an enlargement of the K Series design to 1.6 and 1.8&nbsp;litres was carried out. This was done by using larger diameter cylinder liners and also increasing the stroke. The change required a block redesign with the removal of the cylinder block's top deck and a change from "wet" liners to "damp" liners.<ref name="MGF, damp liner" >{{Cite book
  |title=Project Phoenix: the birth of the MGF
  |last=Adcock  |first=Ian
  |year=1996
  |publisher=Bloomsbury
  |isbn=0-7475-2695-8
  |page=175
}}</ref> The plastic throttle body fitted to the engine until 2001 was manufactured by the [[SU Carburettor]] company. They also included aluminium and larger sized bodies.

The four-cylinder engines were held together as a sandwich of components by [[long-bolt engine|long through-bolts]] which held the engine under compression, though this construction is not unknown, and was used in early lightweight fighter engines from the [[World War I|First World War]]. It had also been used in motorcycle engines and Triumph's "[[Triumph Sabrina engine|Sabrina]]" Le Mans race engine.<ref name="krausebook-ch3">{{cite book |last=Krause |first=G. William |author-link= |date=8 September 2017 |title=The Illustrated History of Triumph Sports and Racing Cars |chapter=The Italian Job |url=https://static.summitracing.com/global/images/technicalarticles/sad-ct596.pdf |location= |publisher=CarTech |pages=42–63 |isbn=978-1613253397 }}</ref><ref name="cad-jun1961">{{cite magazine |last=May |first=Dennis |date=June 1961 |title=Triumph's Twin-Cam! |url=https://archive.org/details/sim_car-and-driver_1961-06_6/page/n65/mode/2up?view=theater |magazine=[[Car and Driver]] |pages=59–61, 64|location= |publisher= |access-date=}}</ref>

The two types of head that were bolted to the common four-cylinder block were designated K8 (8 valves) and K16 (16 valves). A later head design also incorporated a Rover-designed [[Variable Valve Control]] (VVC) unit (derived from an expired AP patent). This allowed more power to be developed without compromising low-speed torque and flexibility. The VVC system constantly alters the inlet cam period, resulting in a remarkably flexible drive: the torque curve of a VVC K-series engine is virtually flat throughout the rev range and power climbs steadily with no fall-off whatsoever until the rev limiter kicks in at 7,200&nbsp;rpm.{{cn|date=March 2019}}

Following the collapse of [[MG Rover Group]] in 2005, the K Series engine started a new and rather interesting chapter in its history.
Two separate re-developments of the engine were taking place by at the time two rival Chinese car firms.{{cn|date=March 2019}}

The Chinese automaker [[Nanjing Automobile]] (NAC) purchased the assets of MG Rover and in doing so acquired use of the [[Longbridge plant]] and the intellectual property rights and production tooling to many designs, including those of the K series engine.{{cn|date=March 2019}}

With the help of Lotus Engineering, NAC went on to produce the N Series an improved version of the K Series with redesigned headgasket and oil rail built on the original tooling.{{cn|date=March 2019}}

This engine featured in the relaunched MG TF in the UK and the MG3 SW and MG7 in China. Contrary to popular belief, the N Series was never fitted to the [[MG 6]].{{cn|date=March 2019}}

When the MG TF ceased production for the final time in 2011, so did the N Series.{{cn|date=March 2019}}

The second development was by the larger Chinese conglomerate [[SAIC Motor]]. SAIC had also previously purchased the rights and blueprints to several of MG Rovers designs. Whilst they had the necessary know-how they didn't have any tooling so had to essentially reverse engineer their version of the engine.{{cn|date=March 2019}}

The advantage of this was it allowed Ricardo 2010, the company tasked by SAIC to carry out development the opportunity to improve the engine in a number of areas.{{cn|date=March 2019}}

The main areas of improvement included the head being redesigned to improve the waterways and structural rigidity and the block was also strengthened.{{cn|date=March 2019}}

All new tooling was used in its production and the quality of materials and that of the aluminium casting process created a much more substantial update than that of the N Series.{{cn|date=March 2019}}

This new engine would go on to power the Roewe 750, the Roewe 550 and later after the two firms NAC and SAIC merged, The [[MG 6]].{{cn|date=March 2019}}