What happened to this engine?

Regarding those older VW Rabbits, Golfs, GTIs and so on, most starting or running problems were due to either a vacuum leak or a fault with CIS injection.
With vacuum leaks it’s often injector seals and with the latter a control pressure regulator problem.

My brother was a grad student at RPI in the late '60’s. One project in a lab was to figure out a material that would work as the seals of the rotary piston in a wankel engine. So, they were given a working wankel from a German company to run tests on. He got a Ph.D in materials and they were working with various ceramic materials for the seals. The motor was physically small, would easily run up to something like 18,000 rpm and for its weight and size was extremely powerful, and very smooth, almost no vibration.

It was an exciting prospect in motor development, lots of advantages, but the seal problem was very real. A few running hours and the seals were shot. For fun they put the motor in a motorcycle frame and found it was almost impossible to ride. It was just too powerful. The problem on the bike was the rear tires kept burning out. The group was successful in developing stronger seals and reported their results back to the manufacturer and the wankel was returned to wherever it came from.

Part of the solution was limiting the rpm range to reduce the seal wear and allow better lubrication. So, that problem was resolved and the motor got more development. Ultimately what made the wankel impractical was the advent of pollution controls. It was a “dirty” motor as far as combustion, but it was mechanically very efficient. Cleaning up the exhaust was a real challenge to meet pollution requirements. It also really liked fuel. All that power and inefficient combustion resulted in relatively low mpg figures.

Still, the mechanical efficiency of the wankel engine remains very attractive. With new technology perhaps it will find a way around problems and end up in production again. It really would be a great back up motor in an electric car or hybrid. Easy to start, very smooth, small size, and light weight. If run at a constant rpm it might meet pollution requirements. In a set up similar to the Chevy Volt a wankel might yet find a home.

@ok4450 at the Benz dealer where I used to work, the older CIS cars had EXACTLY the same problems you just described.

John Deere and NSU had a joint Wankel project at one time dont know what became of it,there was an aircraft in the 70’s called the Wankel Fanliner-Kevin

The Rotary engine : The horsepower of V6, the torque of a four cylinder and the fuel economy of a V8.

@FoDaddy We have a winner!

In 1973 I bought a new Mazda RX2 4 door sedan automatic drive. It was very hard to keep tuned up, it had 2 distributers, so I eliminated one of them and it ran good, however, it was hard to start in winter. It would run at least 110 mph. At 56K miles, my son totaled it out. So I kept the engine and tranny and bought another one that no one could keep it running with a manual tranny and swaped the engine, tranny and the console. I drove it past 100k miles and traded it for an yard tractor. I never saw it agian.

I also know that suzuli put out a one=rotor engine in a motorcycle in the 70s. It was fast and smooth but got poor mileage. I never knew about more than just one.

The Wankel was designed in the late 50’s and ended up in Mazda Cosmo and NSU (now Audi) cars in the 60’s. It also showed up in motorcycles from Suzuki ('74), Hercules, Norton (up to '92). Mazda raced the heck out of the rotary in the US and Europe winning the 24 hours of Daytona 10 years in a row, Le Mans in '91, and 100’s of sports car wins in RX7’s and RX8’s. GM had a serious program in the 70’s to design their own Wankel rotary, planning to put it into the Chevy Monza in '75. GM dropped the engine because Mazda had a patent on the tip seals. GM could not find a way around the patent and would not pay rights to use Mazda’s seal design (Not Invented Here syndrome). The Pacer would have used the GM engine. As race engines, they are fantastic. As street engines with emission equipment, they are complicated and temperamental. Ask anyone who owns a last generation RX7 turbo!

"The Wankel was designed in the late 50’s and ended up in Mazda Cosmo"
Mazda also had the rorary engine in the RX 2,3,4,7 and 8.
I always thot that if they had High Energy ignition and fuel injection, they would start and run fine. The MPG would still be low tho.