Club Sevener : Lotus/Caterham Seven & assimilées

Gn'R357 a écrit :'savais pas qu'il y avaient autant de différences avec le Zetec,/url]

BX a écrit :

Gn'R357 a écrit :'savais pas qu'il y avaient autant de différences avec le Zetec,/url]

oui, ca donne de l espoir, encore 2-3 generations, et je pense que Ford devrait pouvoir atteindre le niveau d evolution d un Rover K...

History of Problems

Rover’s K Series — a lightweight, technically advanced easily tuneable four, or an unreliable and fragile lump?

Three years ago, I bought from the Commercial Director of the Lotus One Make motor sport aseries my Lotus ex-racer. Dave Cooling had recently left Lotus to pursue his own business, but was and remains very close to the company. It was on the drive to the factory, where I had been invited to meet some of the Lotus engineers, that Dave regaled me with stories of how much trouble they had had with the K Series engine – with vibration, with bottom end failure and endless blown gaskets. He revealed that they had thought very hard about junking the K and replacing it with the Honda S2000’s 2litre engine, which as Dave said, would give a “reliable” 237 bhp.

On arrival I was met by Myles Lubbock, chief engineer on the One Make Series and his right hand man John Danby, both of whom knew that I had done a lot of work on the K Series engine in pursuit of a bullet proof 350 bhp supercharged engine. It was immediately clear from the moment that I met them, that they were having all sorts of problems with the One Make race series engines. In fact, they were at their wits ends and had very little respect for the engine. Myles, a serious and able engineer, told me of their problems and efforts to understand them, of even doing a tranche of tests with vibration sensors mounted all over the block to measure what he considered to be the engine’s weakest feature. His assertion was that the engine was made out of very poor quality metal and the block suffered from enormous distortion. He thought the engine fragile, and I suspect more trouble than it could possibly be worth. They were also having immense problems with gasket failure, and even as recently as November 2002 when I spoke to Tony Schute, head of the Elise development program at Lotus, it was plain that Lotus had an engrained belief that the K would suffer gasket failure in any engine over and above the 190PS VHPD specification within an unreasonably short period of time.

Lotus are not the only people familiar to this experience. Another car manufacturer specialising in road/track day racers produced a flagship model a couple of years ago boasting trick throttle bodies, a steel bottom end and 230 bhp / 9200 rpm specification. Caterham’s R500 is a stormer, regaled as being quicker in a straight line than the McLaren F1, but has gained just as vivid a reputation for fragility, notably for putting rods through the block. I myself have met five owners of cars whose engines have done just that, Dave Andrews tells me of more, and all the journalists from the mainstream motoring magazines relate stories of great car – until the engine goes. Similarly, there are engine builders up and down the country who look upon the K as all too breakable in their experience, and the letters pages of the motor sport press have, in their time, been full of stories of cracked liners, blown gaskets, spun bearings, and in fact all manner of woe.

Is the K Series really so poor? And if so, why are some of the leading sports car manufacturers using it? I firmly believe not and rather that it is in many ways the best four cylinder engine around despite its age. During the last three years, I have done a great deal of research into the engine and particularly bottom end loading, in which period I have been lucky enough to be able to call upon the advice and opinion – sometimes very colourful, of the design engineers for K at Powertrain Ltd – MG Rover Engines. In this time it has become very evident that the engine is very sound, its basic design having had just two minor flaws both now remedied, and that the problems that have beset K, are entirely due to poor quality aftermarket components and bad engine building by many of those tuning the engine – people are building problems into K!

Gn'R357 a écrit : le point noir des Rover étant toujours la fiabilité.