Bu as Dembo said, the Rover VVC engines had continuously variable lift and duration...that aspect of the engine at least was quite advanced.

 

No they didn't quite -lift was constant.

The duration of the cams relative to one another was variable (concentric camshafts).

It was a good idea, potentially - another 1/2 way house to full CVTEC.

 

Duh of course you are right it was duration only! Nevertheless it was an interesting idea, and leaving aside the fact it sounded like a bag of nails the VVC engine in my Elise was a pleasure in the way it made its power. A good idea wasted as only Rover could do...

 

You don't think Rover came up with that themselves do you? Wasn't it Yamaha who designed their engines for the last 10 or 15 years before they went tits up?

 

As far as I know the K series was designed by Austin Rover and funded by the good old UK tax payer...

They were of course in collaboration with Honda at the time and the govt wanted them to use Honda engines, but Tebbitt was persuaded to fund the K series...

 

True.

VVC was not developed for the same reason the plastic head dowels were not changed...

Not a pot to piss in.

Later, the NG BMW/Rover engine would have replaced the K, but BMW ran out of patience very quickly.

Hence the Mini used a Chrysler engine, latterly a Peugeot.

 

that was purely to replace the valve springs though as even the best metal springs couldn't close the valves quickly enough once the engine revs went higher than 13k revs. I wasn't aware that it required a compressor though. Don't they just operate from a reservoir of compressed air?

Desdronomic valves are the way to go for high revs, if you can make them work effectively.

 

Why have Honda and Toyota/Yahama stayed just below 9krpm for all their new engines? How come they haven't kept going with the stratospheric numbers and gone into 5 figure territory?

 

Tightening pollution regs.

Things tend to get messy @ high RPM anyway, plus; ever wondered where all the oil goes if you thrash it continually?

 

Also, taking my 14000rpm ZX6R engine as an example (and it's a lot easier in a small short stroke engine) it has 1500 mile service intervals and I suspect an engine with 30-40k on it would be pretty shagged...

(Ironically my Ducati with desmo valves only revs to 8000rpm, but then I believe they fit them in tractors in Italy ... )