Voitures Anciennes

[RobertArthur]

Supposed to continue the futuristic example of the DS, HQ Citroën was playing with the idea to use another engine. How Citroën lost its Wankel courage, from this German source:

" Inside, Michel Harmand reflected the exterior modernity of the CX, brightened up with a colourful ray of extravagance. The CX was given an interior as futuristic as the NSU Ro 80 was denied, even though its designer Claus Luthe had already created it. Conversely, the CX was denied the main feature of the Ro 80: Citroën also experimented with a Wankel CX, it was supposed to have 180 hp - but it never went into series production. After all, the specifications for the CX also stated that it should be cheaper to build than the DS. It was only after a year of dual leadership that Citroën sent its goddess DS to motoring heaven."

Not for the first time a very concise CX history on Wiki. The French Wiki website also shows one of the more traditional engines in the CX 2000

[RobertArthur]

Legendary: the turbine-like, vibration-free running of the Wankel up to 6500 rpm.

Not a little gearbox.

[Hotrodder]

Did they ever solve the problem of rotor tip wear?

[RobertArthur]

Yes, they did. It could have been a happy ending, they finally managed to get a reliable Wankel engine. Too late: oil crisis, fuel consumption... And more important: NSU evolved from a company specialized in motor cycles into a car manufacturer. First jump forward: the little NSU Prinz. Then beam-me-up to the future: the top secret development of the Wankel engine. For a small car manufacturer a where-eagles-dare approach, always lacking financial means to upgrade their research and production facilities. Finally saved - absorbed - by Audi. Another problem: they were launching the Audi A100 (1968). It is rather difficult to have two prima ballerinas in the same show, so one of them had to go....

The almost complete NSU Ro80 story, a bird's- eye view of the industrial landscape of West-Germany in the sixties and seventies, in a video. By the way: google/youtube has an automatic translation function, enable it before starting this video.

Some of the readers probably still know Chris le Bricoleur, his bathroom project and many other DIY adventures. He also was one of the leading European NSU Ro80 experts, kindly invited by the CEOs of Audi to be present at international exhibitions to tell something about this wankel engine, underlining the "Vorsprung durch Technik" slogan of the Audi guys. He spoke German, English, French and Dutch fluently and was not afraid of (technical) Italian and Spanish....Even German websites are not as solid as you might think, from one of them I saved his goodbey to his NSU Ro80, now in Le Musée National de l'Automobile in Mulhouse. Not at home, but not alone. In good company: a Citroën SM.

[Hotrodder]

A very interesting story, and also CLB's involvement.
A pal of mine had a little Sports Prinz in the mid 60s. He was keen on German cars and his next was a Porche 914. I wasn't impressed, but at that time I was only impressed by huge horsepower and big boobs.

[RobertArthur]

About Chris le Bricoleur: although I would have much preferred to continue our cyber friendship, somehow still a happy landing and ending for his Ro80 there in the Mulhouse museum.
Better than this.....

[Polarengineer]

Did they ever solve the problem of rotor tip wear?

No need as the invention of the liquid piston engine has the seals static. I am surprised that US army drones want them because the current batteries are not up to it.
https://www.liquidpiston.com/

[Nomoss]

Did they ever solve the problem of rotor tip wear?

No need as the invention of the liquid piston engine has the seals static. I am surprised that US army drones want them because the current batteries are not up to it.
https://www.liquidpiston.com/

The seals will become worn by sliding friction in a similar way to those in the Wankel engine. This eventually results in them gradually becoming loose in their slots until they eventually tilt enough to be pulled out and dragged around by the rotor. They then break into small pieces which catastrophically destroy the engine from the inside. I know this from experience.

[Polarengineer]

I do not agree with that statement. The dynamic forces acting on the liquid piston seals are much less than in the wankel engine and less even than on piston rings of a normal IC engine. In the first place they are not subjected to centrifugal forces at all nor reciprocating dynamics apart from limited spring action behind the seal.

[RobertArthur]

The three suspects. (© Photo NSU-Pressemappe 1971) The first generation of Wankel engines didn't have a rev limiter. Because of the smooth running over-revving was very easy, down hill on the Autobahn, no disturbing sounds from under the bonnet. City traffic, low speeds, high gear and delivering power: also not good. New materials made their entry, Mazda's guarantee for their Wankel engines: 100,000 miles.

And more maintenance problems (from: Autobild.de).

" Another source of error is the NSU workshops, which are overwhelmed by the revolutionary rotating technology. A few years previously, many of them were still working on Prima scooters and Quickly mopeds. Now, if a customer comes in and reports major problems, they remove the engine and send it back to the factory. In this way, the NSU engineers want to track down the possible weaknesses more quickly. And then they realise that more than half of all engines are in order and can leave the factory again after a few adjustments. Many Ro-80 drivers didn't find this funny at the time. Another source of trouble is the ignition. It is complicated to adjust and prone to wear. For this reason, from autumn 1969 NSU fitted a high-voltage capacitor ignition instead of the conventional coil ignition with its highly stressed breaker contacts, which was easier to adjust and whose contacts lasted much longer. Connoisseurs like club expert Christian von Klösterlein know this: Apart from the initially bitchy engine, the Ro 80s were amazingly sophisticated. "