Wednesday 5th September 2012

Mazda sticks by rotary

Wankel engines will feature in future Mazdas, but perhaps not as we've known thus far

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There’s good news for rotary engine fans, even if their company has been diminished by one recently on PH. Mazda may have ceased production of the RX-8 earlier this year, but the brand’s global CEO is committed to keeping working on Wankel technology.

The last 'proper' rotary Mazda?

Speaking to PistonHeads at the Moscow motor show last week, Mazda CEO Takashi Yamanouchi said “I joined Mazda in 1967 and what motivated me was the rotary engine, and of those that joined that year we formed a club called Cosmo after the rotary engined car [launched in that year]. And in my current position I’m committed to continuing development of the engine.”

However, at least in the near-term, Yamanouchi-san says the future for rotary engines is as the power for range-extended electric vehicles.

“The rotary engine has very good dynamic performance,” he says, “but it’s not so good on economy when you accelerate and decelerate. However, with a range extender you can use a rotary engine at a constant 2,000rpm, at its most efficient. It’s compact too.

Rotaries will return, just nothing like this sadly

“It’s just one of the possibilities for rotary,” he says, leaving the possibility of a future, purely rotary engined car open.

Mazda will launch its first rotary powered range extender EV next year, but will initially only lease a small number of the vehicles in Japan while it further develops the technology.

Speaking at the Moscow show, Yamanouchi-san also said that the former Le Mans winner would like to get back into motorsport but the costs involved meant it would only be an engine supplier to private teams for the mid-term future.  

[CliveM]

So glad they're sticking with it - can't help but feel it'll find a niche somewhere with enough development.

[marcosgt]

Audi (who, via NSU, were early proponents) are also talking of using rotaries in a similar way.

I'll be happy to be driving a rotary charged electric car with 0-60 in 4 seconds in 20 years

M

[Ved]

As a side note, how beautiful is that RX7? Yum

[StottyZr]

I'm glad they've found another use for the Rotary! Hopefully it will be more successful in this application.

It would've been a shame for it to die out.

[otolith]

They aren't so inefficient when used hard - an RX-8 thrashed gives similar mpg to a Civic Type-R thrashed, it just doesn't get much better when driven gently. So as a range extended, a very small rotary operated at peak efficiency when needed and turned off the rest of the time makes a lot of sense - very compact, fairly light, very smooth and quiet.

It just isn't very interesting

[RX7]

otolith said:

They aren't so inefficient when used hard - an RX-8 thrashed gives similar mpg to a Civic Type-R thrashed, it just doesn't get much better when driven gently. So as a range extended, a very small rotary operated at peak efficiency when needed and turned off the rest of the time makes a lot of sense - very compact, fairly light, very smooth and quiet.

It just isn't very interesting

Do they not mean efficient when it comes to power, size and weight?

[Antj]

Even Brian Betamax ( the lesser known inventor of betamax ) knew when to quit.

Come On Mazda step away from the Rotary and concentrate on what works.

[otolith]

What I mean is that a very small rotary making only 30-40bhp but run at its most efficient rpm and load will probably have a good enough brake specific fuel consumption combined with outstanding packaging and weight attributes which make it attractive as a range extender.

[Greg 172]

marcosgt said:

Audi (who, via NSU, were early proponents) are also talking of using rotaries in a similar way.

I'll be happy to be driving a rotary charged electric car with 0-60 in 4 seconds in 20 years

M

Didn't they do a concept A1 with a tiny little rotary under the boot floor? I remember the reports then saying about rotaries (rotarys?) actually being quite economic under the right circumstances and thinking it seemed a great idea. Presumably when you can limit the revs and other factors to limited ranges/tolerences you can make them more reliable too?

[tomoleeds]

Mazda must be sticking to the engine due to the sucess of the RX7 and RX8 engine reliabilty

[HustleRussell]

Doesn't a rotary engine produce about 6bhp and 4ft.lb of torque at 2000RPM? I exaggerate, I like the rotary but I don't think it'll ever be a feasible prospect for a daily driver. Mazda- please put one in a lightweight sports car and a motorbike!

[marcosgt]

HustleRussell said:

Doesn't a rotary engine produce about 6bhp and 4ft.lb of torque at 2000RPM? I exaggerate, I like the rotary but I don't think it'll ever be a feasible prospect for a daily driver. Mazda- please put one in a lightweight sports car and a motorbike!

Doesn't need to produce much of either if it's just running a generator to charge batteries, that's the beauty.

Even a single cylinder piston engine doing the same thing is horribly large, heavy and complicated for the job, not to mention that it would sound and vibrate like a lawnmower...

M.

[Ali_T]

Hmmm, won't constantly stopping and starting a rotary in this application bring with it all manner of flooding risks and catalyst decomposition?

[dele]

Ali_T said:

Hmmm, won't constantly stopping and starting a rotary in this application bring with it all manner of flooding risks and catalyst decomposition?

Ah yes, the joys of flooding my RX7 and needing a tow just to bump start it, the noise of the first initial backfires afterwards always sounded and felt cataclysmic, juvenile smiles all round

[Dave Hedgehog]

Ved said:

As a side note, how beautiful is that RX7? Yum

always loved the RX7, i found it very easy to balance on the throttle

[jamespink]

CliveM said:

So glad they're sticking with it - can't help but feel it'll find a niche somewhere with enough development.

Yea, can't be long now, they've been at it 25 years! Sorry 61 years

Edited by jamespink on Wednesday 5th September 16:41

[HustleRussell]

marcosgt said:

HustleRussell said:

Doesn't a rotary engine produce about 6bhp and 4ft.lb of torque at 2000RPM? I exaggerate, I like the rotary but I don't think it'll ever be a feasible prospect for a daily driver. Mazda- please put one in a lightweight sports car and a motorbike!

Doesn't need to produce much of either if it's just running a generator to charge batteries, that's the beauty.

Even a single cylinder piston engine doing the same thing is horribly large, heavy and complicated for the job, not to mention that it would sound and vibrate like a lawnmower...

M.

Interesting, thanks. Is the assertion that the rotary can be more efficient that a piston engine in this circumstance (no load, 2000RPM?). It makes sense in my head because you aren't accelerating a piston up and down a bore which is slapping about and causing a lot of friction (comparatively speaking)

[anonymous-user]

tomoleeds said:

Mazda must be sticking to the engine due to the sucess of the RX7 and RX8 engine reliabilty

Joking aside, the number one thing they need to sort out is reliability. These engines need to be able to do 200k miles plus without issues IMO.

[jamespink]

Ali_T said:

Hmmm, won't constantly stopping and starting a rotary in this application bring with it all manner of flooding risks and catalyst decomposition?

Can't foresee any tip degradation here at all..

[otolith]

HustleRussell said:

Interesting, thanks. Is the assertion that the rotary can be more efficient that a piston engine in this circumstance (no load, 2000RPM?).

No, I don't think so. I think the assertion is that the small size, light weight and lack of vibration are perfect for a range extender, and that running them as a generator at constant efficient rpm is more efficient than running them connected to the drivetrain, enough so to get over the fuel efficiency problem.