Mazda Will Continue to Develop Rotary Engine

[kach22i]

Jim Cesiro should like this article.

Are you ready for hydrogen power and or Diesel powered rotary engines? How about rotary hybrids?

http://www.carpages.ca/go/autonews/mazda_will_continue_to_develop_rotary_engine.aspx

Mazda Will Continue to Develop Rotary Engine

Justin Couture(Canadian Auto Press) - 4/11/2007

Developed by Felix Wankel, the piston-less rotary engine was an innovative
As far as cars go, the only automaker to still use the rotary engine is Mazda with their RENESIS engine. (Photo: Mazda)
engine layout. Compared to equivalently powerful piston-powered engines, it was smaller, lighter and vastly less complex. After significant investment from the first automaker to adapt rotary engines, NSU (exactly 38 years ago today it merged with Auto Union to become Audi NSU Auto Union AG, and 20 years ago this month, with the last NSU rolling off the line, simply Audi), and then others that dabbled with the technology, such as Mercedes-Benz and General Motors, the only manufacturer to continue production of rotary engines has been Mazda.

However, there has been a fair amount of speculation that, due to low demand and high development costs, Mazda might abandon the rotary in the end. After all, it only builds one rotary-powered car, the RX-8, which is hardly a role-model business case for profitability in the modern age of maximizing economies of scale. For a short period of time, between 2002 and 2003, the time period between the demise of the Japanese-market RX-7 and the launch of the new RX-8, Mazda did not produce a car with a rotary powered engine. To clear any doubts about the demise of the rotary, Mazda has just announced that it will be developing a new generation of RENESIS rotary engine, slated to arrive in 2010.
The RX-8 is the only car currently in production to use rotary power. (Photo: Mazda)


When it was launched in 2003, the RENESIS engine marked a giant step forward in rotary engine technology. Mazda had developed ways to get around the emissions issues by relocating the intake and exhaust ports, which allowed the RX-8 to surpass European and US emissions standards. Mazda also used the rotary engine as a platform for its hydrogen program; it currently uses adapted versions of the RENESIS engine for hybrid-powered Mazda Premacies (the equal to the Mazda5), and Mazda RX-8s.

Earlier this week, Mazda unveiled the second generation RENESIS rotary at a business conference in Tokyo, Japan. The primary goals that Mazda set out for the new engine are to further reduce emissions output, increase efficiency, but most importantly reduce fuel consumption. The tiny 1.3-litre rotary engine in the RX-8
Mazda is investing big money in hydrogen power; it's keeping the rotary alive with this project. (Photo: Mazda)
produces 232 horsepower and 159 lb-ft of torque, but, consumes 12.8 l/100 km in the city and 9.8 l/100 km on the highway. That's more fuel and significantly less power than what Nissan's 350Z consumes and produces.

Mazda also has plans to develop a brand new rotary engine specifically for its hydrogen program. Not much is known about this powerplant, but Mazda's goals are to have it produce equivalent power to a 3.0-litre V6 engine, while having a range of 400 km (250 miles) between fill-ups.

Though the hot topic of the conference was the rotary engine, Mazda also displayed its plans for upcoming conventional gasoline and diesel engines. For its regular gasoline engines, Mazda's goal is to improve performance by between 15- and 25-percent, while reducing fuel consumption by 20-percent. As for its diesel engines, Mazda wants to cut tailpipe and CO2 emissions down to levels where it can meet the Euro6 and the strict US emissions standards, demonstrating that the brand wants to enter a diesel vehicle in the North American market. Finally, Mazda will also be unveiling the second generation Mazda6, which will most likely take place at this year's Tokyo auto show.

[dagriff]

Whatever.... they will still sound like crap.

[unimog406]

rotaries havn't caught on yet for a very good reason,:
they're junk. they eat oil, gas, and everything else, giving back only a helluva noice, a billion rpms, and 0 torque. yeah, i've driven an rx-7 too, and yeah, it was a bit of a kick, but the engine simply isn't practical for most people

[BertBeagle]

Wonder if they will go back to Le Mans and kick butt like they did in 91 when they won the race? It is a cool engine.

[Moneyguy1]

I remember doing some work for Gleason's in Rochester NY on the machines the were used to fabricate the first iteration of Wankel engines. Fascinating project.....

[dd74]

Kudos to Mazda. The rotary is what put them on the map, and they're showing due respect to the brand by not letting its historical significance be forgotten.

It reminds me of the difference between Disney and Warner Bros.

Disney continually updates Mickey Mouse with new cartoons and other projects, while Warner Bros. has effectively allowed Bugs Bunny and the Looney Tunes to die into obscurity.

Both studios were founded in large part on their animation.

But only one seems to care about that history and is remembered for it.

[berettafan]

i'll happily watch 28yr old reruns of Looney Tunes vs. the crap Disney is putting out these days. Disney hasn't produced a quality movie/cartoon in a LOOOONG time IMO. Lion King, etc. are just the same damn story rehashed over and over again with horrible soundtracks and misguided messages hidden in the background.

Mazda has a gimmick and they're sticking with it; seems like they need to do something to maintain brand recognition.

[oldE]

Mazda has kept the rotary as their 'halo piece', but if they dropped it, I doubt many would notice.
Mazda's current strengths are the MX-5, (the best selling convertible sports car of all time), the 3s (which shares a chassis with the Volvo S-40 and the European Focus) and the 6. The latter two cars are quietly going about their business, managing to look just a bit different from their competitors and, through Mazdaspeed, adding a serious punch for those who want it.
For the 'crossover crowd', they have managed to take Ford's Edge platform and produce the CX-9, a 7 passenger vehicle that makes the Edge look like the box it came in.
In addition, the longer term reviews I have read, (and my neighbor's reports on their MX-5s, 3s and 6s) seem to indicate these puppies are put together well.
I wonder if it is just pride that keeps Mazda putting money into the rotary.

Les

[Dantilla]

While the rotary has some great attributes, it's biggest problem, one that cannot be fixed, is poor volumetric efficiency.

A crescent-shaped combustion chamber is simply not as efficient as a round cylinder. Added to that is the combustion forces pushing the rotor at an angle- not directly onto a piston dome.

I had a first generation RX-7, and liked it. But with gas prices climbing, the rotary is less attractive, and will most likely remain an oddball.

[legion]

I always thought that a rotary should be more efficient as it has no reciprocating mass. Everything moves in one direction--nothing ever reverses direction.

[oldE]

" Everything moves in one direction--nothing ever reverses direction."

Not exactly the case. The rotors revolve around an eccentric, (a short-throw crank, if you will) which means its mass is moving back and forth a few inches while it spins. Think of trying to hold a few pounds of aluminum as it spins and moves its axis through a three inch circle with each revolution, at 8000 rpm.
A whole lotta shakin' goin' on!

Les

[Jims5543]

Les, actually they are quite smooth, they use a counterweight on the eccentric shaft behind the flywheel to balance it out. Smoother power than any other car I have owned.

It moves in a circle, no transfer of up and down motion to circular motion, this makes for a very smooth engine.

Is it pride or a rabbid following that keeps the rotary in production. The same could be said for the rear engined 911 platform, obviously the Cayman posses a much better balanced platform with its mid engine layout and could easily replace the 911 as the super car that Porsche makes.

The same goes for the Rotary engine, I am not interested in the RX8 at all, I think the Renesis engine, while a remarkable piece of technology putting out 250HP with out a turbo is amazing, Its what happens to them when you boost them that disapoints me. The side seals let go.

So here I am stuck with my 20 year old RX7 making over 500 HP from 1.3 liters because everyone knows they have poor volumetric efficiency running circles around most every car I encounter on the track and at autocrosses.

I am now challenging other members of a local wesite to beat me in an Autocross, think of it as street racing but with turns and timing lights, I will pay anyone that beats me $100 but if they loose I get $50. I am going to make a lot of money with my poorly designed poor volumetric efficiency, Rotary car.

Hopefully Mazda will grow some balls and turn out a 20B powered RX7 in the future along the lines of the one Pettit Racing makes. They transplant a 3 rotor engine (20B) into a 3rd Generation RX7 and it makes 550HP easily. Many go into the 700HP range with them.

Consider my 2 rotor engine put 400 to the wheels and will soon put over 450 to the wheels and trust me there is plenty of torque. Enough to make my 10" wide Hoosier slicks gove up the fight as I rail through the RPMs in 2nd and 3rd Gear making me use my right foot an aweful lot to keep it straight.... god I love that car.

You may now continue with your Rotary bashing.

[Komenda Fan]

Rotaries are fantastic engines, I was lucky enough to rebuild one once and was amazed at how simple they really are. I understand the rotor seal issue is largely solved now, and I really like that there is another option out there to the piston engine, which really is an antiquated idea...

[Dantilla]

Jim, I said that rotaries have great attributes, and that I like them. No bashing intended. But do you disagree about their efficiency?

While the horsepower per displacement is spectacular, the horsepower per fuel used is usually less than a piston engine.

You've got gobs of power from your RX-7, but I doubt you would consider it an economy car.

Good points:

-They rarely suffer a catastrophic failure. If one rotor goes, you drive home with less power.
-Smooth.
-High rpms can deliver high horspower numbers.
-Compact design.

The bad:

-The crescent shaped combustion chamber has poor volumetric efficiency. More gas, more emmissions.

[BertBeagle]

Originally posted by Dantilla
Jim, I said that rotaries have great attributes, and that I like them. No bashing intended. But do you disagree about their efficiency?

While the horsepower per displacement is spectacular, the horsepower per fuel used is usually less than a piston engine.

You've got gobs of power from your RX-7, but I doubt you would consider it an economy car.

Good points:

-They rarely suffer a catastrophic failure. If one rotor goes, you drive home with less power.
-Smooth.
-High rpms can deliver high horspower numbers.
-Compact design.

The bad:

-The crescent shaped combustion chamber has poor volumetric efficiency. More gas, more emmissions.

I think the poor efficiency is in part due to Mazda not focusing on it as a high priority. Just a guess but with the attention on oil we have today that could change.

True, Mazda couldn't win Le Mans until they were given some concession for fuel millage (teams are allocated fuel for the race). But it was a marginal problem. I have had a few RX7's and never was concerned about millage. Maybe the old 12A or 13B used 5% / 10% more fuel than say a 280Z or 911 of the day. Not sure but the point is - so what. The fuel efficiency argument was laid down by those looking for a negative and perpetuated because in reality there are few negatives associated with the engine. It is a great engine and the cars are awesome as well. I especially liked the second generation.

[Jims5543]

Dantilla - I agree if your looking for good gas milage the Rotary is not for you. But HP comes at a price. A similar 1.3 liter piston engine would make 90-120HP at best where a 1.3 liter Rotary is making 230-250HP so, yeah its not going to be a 30+ MPG engine.

My car gets 5 MPG on the track, what do you guys get with your 911's? I am curious?

City driving I get 12-14 MPG with the RX7 and I get 20 MPG with my 911.

Highway driving I get 18-20 MPG with my RX7 and 30-33MPG with my 911.

So, yes, I agree it does not get good gas milage.

I will be dynoing my RX7 really soon, I'll be sure to post up the dyno sheet so you can see how soon power comes online with my engine, I think you will be suprised. Keep in mind I set this car up to be an Autocross monster.

[berettafan]

jim do you have any videos of this puppy autocrossing?

i think it's time for Pinks to hit the cones!

[kach22i]

Originally posted by BertBeagle
I think the poor efficiency is in part due to Mazda not focusing on it as a high priority. Just a guess but with the attention on oil we have today that could change.

I saw one of the aftermarket tuners on Speed TV going on about the high performance Diesels (maybe it was Roush) he has been working on. The pre-detonation problems of gas and spark plugs engines do not exist with Diesel, all he has to worry about the the strength on the parts now and loves it.

I'm thinking maybe diesel is a good direction for the rotary for the same reasons, we shall see.

[David]

I agree that the sound of two rotor isn't too great, a 3-rotor on the other hand sounds really wicked, like Ferrari V12 wicked. Of course they get even worse mileage than the 2 rotor.

Here's the '58 Sprite that a friend and I drove at several SCCA autox nationals. He took home a few championships while I just had fun warming the tires . It has a 20B 3-rotor with peripheral ports and slide valve injection for over 400 hp in a 1600 lb car! He sold it last year to buy a FSCCA car which is also pretty fun.

[Wrecked944]

I always thought it would be cool if Mazda designed the rotary to be more "modular" - so you could build up a three, four, five, six whatever rotor motor depending on your budget and application. It would make displacement mods way easier than they are for a piston motor.