Rover K engine

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A 1.4l DOHC K-Series engine in an MG ZR
A 1.4l DOHC K-Series engine in an MG ZR

The K-Series engine is a series of engines built by Powertrain Ltd, a sister company of MG Rover. The engine was built in two forms: a straight-4 cylinder, available with SOHC and DOHC, ranging from 1.1 L to 1.8 L; and the KV6 V6 variation.

The K-Series was introduced in 1988 by Rover Group as a powerplant for the Rover 200 car. It was revolutionary in that it was the first volume production implementation of the low pressure sand casting technique. This works by injecting liquid aluminium into an upturned sand mould from below. In this way any oxide film always remains on the surface of the casting and is not stirred into the casting structure. This production technology overcame many of the inherent problems of casting aluminium components and consequently permitted lower casting wall thicknesses and higher strength to weight ratios.

The engine was introduced in 1.1 L single overhead cam and 1.4 L dual overhead cam versions. The engines were unique in being held together as a sandwich of components by long through-bolts which held the engine under compression.

The two types of head that were bolted to the common 4-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 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 rpm.

By comparison, the V6 engines are more conventional engines that do not make use of the through bolts to hold the head to the block.

The 1.8 litre versions are often used in kit cars and are starting to be used in hot rods, especially as a popular swap into the MG Midget, Morris Minor and the Caterham versions of the Lotus 7.[citation needed]

Contents

[edit] K-Series problems

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The engine's head-gasket was made from a steel core plate with silicon rubber beads to seal water and oil ways rather than the more traditional materials. However, the redesign of the cylinder block to enable the capacity to stretch to 1600 and 1800 cc resulted in a lack of stiffness. This allowed movement across the gasket face and subsequent gasket failure. The design of the cooling circuit was also less than optimum, allowing a hot engine to be suddenly flushed with cold water when the thermostat opened. This "thermal shock" put more stress across the gasket face. These factors were particularly severe in larger vehicles such as the Land Rover Freelander.

The Freelander problem was relieved to a certain extent by a special pressure release thermostat which, with the aid of a spring loaded valve, allowed a small amount of coolant to bypass the thermostat at high engine speeds regardless of engine temperature.

A modification made in an attempt to reduce the rate of gasket failure was to replace the plastic dowels with steel dowels in the cylinder block top face this helps reduce the head movement relative to the cylinder block. The rubber sealing beads were also modified to give improved attachment to the gasket core plate.

More recently, Land Rover have released a reinforced MLS (Multi-Layer Steel) head gasket for the K-Series engines, which until mid-2005 were fitted to the 1800 cc petrol variants of their Freelander model. A modified oil rail was also developed to be used in conjunction with the gasket to improve block stiffness. Time will tell as to whether the improved design will cure this fault of the K-Series engine, but many professionals and enthusiasts now recommend this new design over the standard gasket as fitted by MG-Rover. To date, the results appear to be good.

In the motor trade, most unmodified K-Series engines are expected to suffer head-gasket failure at around 90,000 miles. Water and oil mixing, resulting in the dip-stick being coated in a brown slush is the most common symptom, requiring significant effort to clean out before replacement.

[edit] 1100

All 1100 engines displace 1.1 L (1120 cc/68 in³). Three variations were created:

  • SOHC K8 8-valve, Carburettor, 60 hp (44 kw)
  • SOHC K8 8-valve, SPI, 60 hp (44 kw)
  • SOHC K8 8-valve, MPI, 60 hp (44 kw)
  • DOHC K16 16-valve, MPI, 75 hp (55 kW)

Cars that came with the 1100:

[edit] 1400

Engine Codes: 14K2F (8V), 14K4F (16V), ???

All 1400 engines displace 1.4 L (1396 cc/85 in³). Five variations were created:

  • SOHC K8 8-valve, Carburettor, 75 hp (55 kW)
  • SOHC K8 8-valve, SPI, 75 hp (55 kW)
  • SOHC K8 8-valve, MPI, 75 hp (55 kW)
  • DOHC K16 16-valve, SPI, 90 hp (66 kW)
  • DOHC K16 16-valve, MPI, 103 hp (76 kW)

The K16 90hp variant is exactly the same as the 103hp version apart from a restrictive throttle body designed to lower the cars insurance group.

Cars that came with the 1400:

[edit] 1600

Engine Code: 16K4F

All 1600 engines displace 1.6 L (1588 cc/96 in³). Two variations were created:

Cars that came with the 1600:

[edit] 1800

Engine Codes: 18K4F, 18K4K (VVC variants)

All 1800 engines displace 1.8 L (1795 cc/109 in³). Six variations were created:

  • DOHC K16 16-valve, MPI, 117 to 120 hp (86 to 88 kW)
  • DOHC K16 16-valve, MPI, 136 hp (100 kW)
  • DOHC K16 16-valve, MPI, VVC, 145 hp (107 kW)
  • DOHC K16 16-valve, MPI, VVC, 160 hp (118 kW)
  • DOHC K16 16-valve, MPI, turbocharged, 150 to 190 hp (110 to 118 kW)
  • DOHC K16 VHPD - Very High Performance Derivative 16-valve, MPI, 177 hp (130 kW) or 192 hp (142 kW) (Lotus version) (Uses VVC unique cylinder head casting (similar to VVC casting), has big valves, but with fixed cam timing - No development input was requested from Rover)

Cars that came with the 1800:

[edit] External links