How is it that Mazda wound up with that engine? I'da thought that BMW, Audi, VW, MB would have developed it, since it was apparently invented in germany. Popular Sci was touting that engine since the early '60s iirc.
Are there any drawbacks to it? My BIL gets an easy 350 hp from his '93 RX7, with a 1.8 L engine. Car is like a rocket. Sposedly the engine had some emissions problems, but Mazda musta fixed them in the RX8.
FYI, a Suzuki 500 cc motorcycle had a Wankel engine. Ugliest goddamm motorcycle god ever put on earth. Not a quick bike at all.
They were one of the companies that originally licensed it from NSU/Wankel for development in the early '60s. Actually, Mazda hit upon a workable engine before NSU, much to NSU's embarrassment. As I recall, Mazda was asked to delay introduction of the Cosmo until NSU could debut the Prinz, so NSU could say it was the first to release a rotary to the public.
By the time the gas crisis hit, some dozen companies, including GM, Mercedes Benz and Citroen bought licenses to make the engines. Mazda was the only one that carried the thing through all the way.
Lots of things were developed in Germany. NSU had some daring people, more so than the big guys, and they were willing to take the plunge. I think Felix Wankel was an NSU engineer.
Unfortunately, the costs of development (of the engine and of the Ro80 car), plus the warranty costs of fixing failed engines, eventually brought NSU down by about 1968, and it was absorbed by Volkswagen/Audi.
Everybody was. It was the "wave of the future".
It was the engine that went "hummmm" instead of "boing boing boing". Anybody remember those ads?
Not any more, besides less-than-great gas mileage. And they really, really ARE that smooth. Smoother than a V8.
I got 19mpg out of my '74 RX-4.
They had apex seal problems. I had an RX-4 (the first 13B) which suffered from that exact issue.
The biggest gotcha was that when the rotary failed, it didn't go bad over months and miles, it failed RIGHT NOW. That stranded drivers and also pissed them off. Sales tanked. Mazda almost got into financial trouble themselves. The GLC saved them.
I think they kept on building rotaries all the way up to the RX-7 in
1979, updating the RX-4 chassis over the years.
I think Norton put a rotary in a bike at one point, too.
I am not going to cheat, but I think NSU (Germany) first came out with the first Wankel engine cars, in Germany.There is/was a German Motorcycle outfit that built at least one Wankel engine Motorcycle.Wankel engines are a good idea, if they can be improved good enough. cuhulin
I think I have read before that Rudolph Diesel's first engine blew up and nearly killed him.I think he originally intended his engine(s) to run on Coal.He disappered from a Ship between America and Europe.Nobody knows exactly what happened to him.
Not much more that a few years ago, Cadillac was experimenting with running an engine on powderd Coal and Cadillac had a vibrator (no puns, Please) gizmo hooked up to that engine to help keep that powdered Coal moving along. cuhulin
Felix Wankel invented the engine. Licenses were issued to many companies, including Curtiss-Wright in US. NSU and Mazda were the only two companies who brought it to production in an automobile.
There were both emissions and efficiency problems due to same cause- the surface area to chamber volume is higher than in piston/cylinder configuration. The added chilling of charge increases emissions and reduces efficiency somewhat.
Additionally, seal wear has been a problem. Supposedly Mazda has solved that problem. However, with the problems it has had, there is no strong driver to use the engine. It is most appropriate where specific power is a big driver, since its power to weight is very good. So it is best for high performance cars and aircraft.
While it has fewer parts, fancier machining has made it no cheaper to produce than piston/cylinder engine.
Felix Wankel invented the engine. Licenses were issued to many companies, including Curtiss-Wright in US. NSU and Mazda were the only two companies who brought it to production in an automobile.
There were both emissions and efficiency problems due to same cause- the surface area to chamber volume is higher than in piston/cylinder configuration. The added chilling of charge increases emissions and reduces efficiency somewhat.
Additionally, seal wear has been a problem. Supposedly Mazda has solved that problem. However, with the problems it has had, there is no strong driver to use the engine. It is most appropriate where specific power is a big driver, since its power to weight is very good. So it is best for high performance cars and aircraft.
While it has fewer parts, fancier machining has made it no cheaper to produce than piston/cylinder engine.
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The Law of No Free Lunch? :) :(
I think the History Channel et al did a ditty on the Mazda rotary. It struck me, as a wannabee machinist, just what a herculean task this engine production must have been. From both machining and organizational povs.
Actually, GM did a lot more work on it than any of the German companies, IIRC. Then they abandoned it and only Mazda carried the torch. Another bit of trivia- the AMC Pacer was designed with the intent of using a GM-built Wankel engine, and when GM pulled the plug on that engine AMC had to substitute their own straight-six at the last minute.
A few:
Oil consumption (oil is deliberately sacrificed, albeit slowly, to lubricate the rotor tip seals). That adds to emissions, too- really jacks up the unburned hydrocarbon percentage.
Rotor tip seal wear (largely contolled by materials selection and sacrificing oil, see above :-)
Fuel distribution sucks because the "intake" area of the engine always stays much colder than the "combustion" area. Remember that the "combustion chamber" loaded with fuel/air mix sweeps around the engine as it runs, unlike a piston engine, so it has to move past "cold" parts of the rotor chamber before getting to the spark plugs and hot "combustion" area. Fuel injection helped that a lot, but its still an issue that both reduces fuel efficiency and increases emissions.
Because at the time, the Japanese were more willing to take a jump into an unproven technology than anyone else. Mazda was part of a big heavy machinery and machine tool combine that wanted to get into the car business and wanted something different. The Wankel sure was different.
Poorer gas mileage and lots of emission problems from burned oil. The _problem_ is that Mazda was introducing these cars into the US market in the seventies, just as gas prices were climbing and emissions controls were coming into place.
The Wankel has to burn some amount of oil in order to keep the seals working properly. This means it's always going to have higher emission issues than a comparable 4-cycle engine.
The thing about the Wankel is that it produces huge amounts of power and is very efficient at full throttle, but it is a comparatively poorer performer at lower throttle settings. This would make it a better choice for applications like aircraft and marine engines which are normally run at or near full throttle most of the time.
I would LOVE to see stationary generator packs made with small 2-rotor Wankel engines. Quieter generators make the world a better place, they run mostly near full throttle, and the emissions are less of an issue.
Probably because the big german automobile companies were very successful with piston based powerplants and they saw no real benefit from having to create a whole new production line for a motor that would in all likelihood be just a sideshow.
Well, the drawback really ends up being whether it can offer any improvement over existing piston engine technology. After bankrupting itself with a premature conversion to the rotary in the 1970's Mazda has spent the last 30 years bringing it up to snuff with piston engines.
In a sense it is an oddball like the two cycle engine. Both designs squeeze a lot of power from a compact engine. But for differing reasons neither design really offers an improvement over more traditional powerplants.
Actually, there were others, but NSU and Mazda were the most successful. Citroen, among others, had a production rotary car. Many more companies had licenses to study production, but very few went beyond the prototype stages.
Look for where it says, Model Airfield Engine Types.(or something like that) A bunch of years ago, I saw an ad in a magazine about little model Wankel engines for model airplanes.I think a company by the name of O.S.Max makes them, or sells them.There are magazines available pertaining to Model Airplanes.There might be some ads in some of those magazines about Wankel engines.I wouldn't mind having one of those little model Wankel engines to play with.A few years ago, I saw an article on the internet about somebody made a Wankel engine about the size of a quarter. cuhulin
z wrote in news:1184788986.440100.284180 @e9g2000prf.googlegroups.com:
Mine did.
The engine ground to a halt on the freeway with 80,000 miles on the clock. It was tow truck time, as the starter wouldn't even budge the engine.
I pulled the engine apart some weeks later to actually see what had happened. The rear rotor's housing was badly scored and galled. The guess was made at the time that that rotor's oil feed line had somehow become blocked, leading to catastrophic failure of the apex seals. The front rotor, on the other hand, was in fine shape.
Remember how the early rotaries had that separate oil tank that looked like a brake fluid reservoir? There were nylon lines from that to each rotor. You had to keep the tank topped up with engine oil, to feed lube to the apex seals. The apex seals had no other source of lubrication.
By that time (1987) the car was way too old for any sort of factory help, so a used JDM engine was installed. This thing was a nightmare to install, with lots of custom fabrication for brackets and things.
The other day I was looking through my collection of fasteners for some nuts and bolts. I discovered I still have two of the corner seals from that engine.
It's been done, but the high power settings in aircraft (typically 65 to 75% in cruise) is a lot higher than a car's cruise requirements, and the waste heat becomes hard to dispose of. Cooling systems have to be very well designed and the limiting factor, I think, becomes the coolant and coolant flow rates. John Deere fooled with it, too. Sachs made snowmobile versions of it for Arctic Cat. See
NSU was the first company to market cars with Wankel engines. NSU was eventually absorbed into VW, but they long ago gave up on Wankels. Mazda is the only company that has had any success at selling them. The poor fuel economy associated with Wankels pretty much limits them to niche markets these days. Before the first fuel crisis of the 70's GM was well on the way to marketing Wankel powered cars.
Actually Wankels are not particularly efficient at full throttle either. The oddly shaped and constantly moving combustion chamber results in relatively low compression ratios and does not promote good combustion. The big advantages to Wankels was high power to weight ration and relatively simple construction. In the 70's when gas was relatively cheap lots of companies were planning Wankels. There were some really large ones planned for stationary power plants. However when fuel prices climbed, interest in the Wankel went away.
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