Rover K engine
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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 Metro 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.
These two types of head that were bolted to the common 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.
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.
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.
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[edit] K-Series problems
The engine's head-gasket was made out of an innovative silicone-type substance rather than the more traditional materials. However the cylinder head waterways were poorly machined and the thermostat was placed in a less than optimum position. These factors often resulted in head-gasket failure, particularly in larger vehicles such as the Land Rover Freelander.
In these applications the greater body weight caused the engine to heat-up too quickly compared to the rest of the system. The thermostat would then open and a sudden rush of cooler water would enter the head causing temperature distortion.
This 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 cool water to enter the head so that the engine warmed-up a little slower and more evenly. However, the optimum solution of moving the thermostat to the outflow from the head, allowing that rest of the water system to warm-up with the engine, was never implemented.
Another modification to reduce chance of the head-gasket failing again, is to insert steel dowels into the cyliner block when changing the head-gasket which renforces the new gasket.
More recently, Land Rover have released a reinforced MLS (Multi-Layer Steel) head gasket for the in-line four cylinder, and 24 valve V6 versions of the K-Series engine, which until mid-2005 was fitted to the petrol variants of their Freelander model. A modified oil rail was also developed to be used in conjunction with the gasket when fitted. Although only time will tell as to whether the improved design will cure this fault of the K-Series engine, many professionals and enthusiasts now recommend the fitment of this new design over the OE standard gasket as fitted by Powertrain K-Series engines, especially in models such as the MG F/TF and Freelander, where the applications are their most stressful.
[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)
- DOHC K16 16-valve, MPI, 75 hp (55 kW)
[edit] 1400
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)
[edit] 1600
All 1600 engines displace 1.6 L (1588 cc/96 in³). Two variations were created:
[edit] 1800
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 160 hp (110 to 118 kW)
- DOHC K16 16-valve, MPI, VVC, 177 hp (130 kW) (Lotus version) (Uses VVC head, as has big valves, but with fixed cam timing)
