Return of the Rotary?

[B.Martin]

This has been buzzing around the internet for the past few days, i thought i\'d post it for those who might not have seen it,.

Despite plans to stop production of  the RX-8 sports coupe in June and no commitment from management to  replace it with another Wankel-powered car, Mazda may be on the verge of a major rotary breakthrough.
                                                                 Mitsuo Hitomi, general manager-powertrain  development, says the auto maker soon will complete development of an  all-new rotary engine that meets future fuel-economy and emissions  standards.

                                                             While Hitomi won’t confirm a completion date, his disclosure is  evidence the rotary is alive and well at Mazda and that a new car  powered by the engine could be on the way. “We think we’ve found a way to improve  the rotary’s fuel economy to be truly equal to that of conventional  piston engines and, if so, we believe we can reintroduce the rotary to  the market,” he tells WardsAuto in an interview.

                                                             Hitomi declines to pinpoint when that  might happen, but suggests the timeframe roughly would be equivalent to  any other engine plugged into one of Mazda’s vehicle programs. Best  guess is two years, once the application has been determined.
                                                             Fuel economy and emissions were improved  in the developmental engine “first, by changing the shape of the  troichoid housing,” the Mazda executive says.
                                                             “The rotary has many seals, and  ‘sealability,’ particularly at the apex, or tip, of the rotor has been a  longstanding problem” dating back to the mid-1960s and the Cosmo Sport,  Mazda’s first rotary car.

                                                             “Even with our current 1.3L Renesisrotary, gaps  can develop between the apex seal and troichoid housing in light-load  operation when imbalances in centrifugal force and gas pressure occur,”  he says.
                                                             Specifically, centrifugal force pushes the seal onto the housing  surface. In low engine-rpm ranges, or under low-load conditions, gas  pressure in the combustion chamber can cause the seal to lift off the  surface, resulting in combustion gas leaking into the next chamber.
                                                                 By changing the shape of the troichoid  housing, the seals remain flush to the housing, Hitomi says. “In  addition to reducing emissions, better sealing improves fuel economy and  overall performance.”

                                                            A second engineering enhancement focuses on ignition.
                                                               “I can’t specify how we plan to address  this problem,” the Mazda engineer says, “but the rotary’s spark plug is  in a recessed position (below the housing surface), compared to that of a  piston engine.

                                                             “This causes ignitability problems and increases fuel  consumption. We’ve found a way to make dramatic improvements,” he says.
                                                            In June, AutoCar reported Mazda would introduce a laser-injection system to replace conventional spark plugs.
Hitomi counters popular perception that a rotary engine’s fuel economy is inherently poor.
                                                             “In the past, Mazda engineers made a  conscious decision to focus on the rotary’s weaker points – low torque,  for instance,” he says. “This led to adopting a complicated and large  variable-intake system, as an example.

                                                             “Moving forward, we plan to put greater  emphasis on the rotary’s strong points – low vibration, compact size and  high power output. And in this way, we can improve fuel economy.”
                                                            One result of that: Mazda will simplify the intake system, which in turn will reduce engine size.
                                                             Hitomi believes the new engine eventually  will be adopted for extended-range electric vehicles like the Chevrolet  Volt. He doesn’t say so, but that could mean a future RX-8, RX-9 or  even an RX-7 EREV.

                                                             Mazda isn’t alone in looking at EREV applications for  rotary engines, which are drawing interest from others, including  engineering experts AVL, for their compact size and light weight.
                                                             The new Mazda engine will not necessarily  be the 16-X prototype displayed at the 2007 Tokyo Motor Show, which  reportedly was targeted at 1.6L in displacement and would generate 350  hp.
                                                           
Mazda’s Skyactiv fuel-efficiency technology could be applied to the new rotary, as well.
                                                             “I think that whatever engine we  introduce – conventional gasoline and diesel or rotary – the technology  is applicable,” Hitomi says.
                                                             At a press briefing in December, Hirotaka  Kanazawa, senior managing executive officer in charge of Mazda’s  technical operations, openly discussed three Skyactiv engine series: the  gasoline Skyactiv-G now on the market, diesel Skyactiv-D and rotary  Skyactiv-R.

                                                             Since 1967, when Mazda introduced Cosmo Sport, the auto maker has  sold nearly 2 million rotary vehicles. In the engine’s 1970s heyday,  four out of five Mazdas sold in the U.S. were rotaries.

http://wardsauto.com/vehicles-amp-technology/mazda-design-breakthrough-may-give-rotary-new-life

[TiddlesRX7]

Sounds good to me!

[Ada7]

Wish they get on with it. The whole rotary world is waiting for something new to come out

Adam

[TiddlesRX7]

It is but I\'d rather they took their time with it and got it right rather than rush it out only to have problems.

[Grant Monkhouse]

2 years is a long time to wait, the european emmissions standards will no doubt have become more rediculous by that time and this new engine/cars will more than likely just end up being prototypes for advertising, a bit like the furai. even though that did actually run.
 
they would be better offering the current mx5 with the renesis engines in them from the factory/shop floor like they intended to so in the first place with the current mx5.

[B.Martin]

they would be better offering the current mx5 with the renesis engines in them from the factory/shop floor like they intended to so in the first place with the current mx5.

I\'d like to see that, i remember i got a redline mag with a MX-5 renensis in it. Looked very factory fit i\'ll see if i can find it.

Edit - i found it here -> http://www.mx5-twins.de/RX-55_Fotoshooting/index.html

[Ada7]

For me they\'ve now got to produce something that can compete with the \'now not so new\' Datsan GTR

Adam

[bmatharu]

That\'s a different ball game though Adam, a different price bracket and market...

[B.Martin]

They should certainly compete with this new Subaru BRZ and the Toyota GT-86, that is perfect for mazda to challenge!

[Ada7]

That\'s a different ball game though Adam, a different price bracket and market...

No reason that they can\'t though. The FD was made and priced to compete with the Porkers of the time so why not build something that can slug it out with the other big boys in the playground

Adam

[B.Martin]

The market is not really that big for it though, i mean the GTR probably doesn\'t sell that many models really.

[Grant Monkhouse]

For Mazda to compete with the GTR they would need to run a 3rotor or the new 2 rotor with a single turbo.

4wd would be needed and as Mazda like to hone their cars around light weight strength and efficiency they won\'t even consider 4WD IMO.

I do like the mention in the report of variable intakes that Mazda will simplify for production. I can see now if they do variable length intakes many people having clear air bids to show off the fancy intakes.

[Will66]

The reason the Renesis fits in the mk III MX-5 so well is that the Mk III MX-5 uses a modified RX8 chassis, that conversion was done with the driveline from a damaged RX8.

I can see something along the lines of the Subaru BRZ working, if they can squeeze more mpg out of it.

[Grant Monkhouse]

I\'d like to see that, i remember i got a redline mag with a MX-5 renensis in it. Looked very factory fit i\'ll see if i can find it.

Edit - i found it here -> http://www.mx5-twins.de/RX-55_Fotoshooting/index.html

There was a feature in banzai magazine last year, a company was doing it as a conversion, the transfer looked like factory standards. Aparently the rx8 and mx5 have similar parts used for the steering/suspension so it all prety much bolts straight into the mx5 from the rx8.

However total cost for this conversion was in the range of 40,000 euros. You have to buy a new mx5 and a donor rx8 for the engine and associated bits.

[jetpilot]

They should certainly compete with this new Subaru BRZ and the Toyota GT-86, that is perfect for mazda to challenge!

I am not sure its a challenge, they only need one rotor to compete with that!