> I interview Seiji Tashima, the engineering expert
for Mazda's new
> rotary, at Tokyo on your behalf. Here are a few
details he revealed:
> rotor width reduced by 5mm saves weight, improves
apex seal performance
> trochoid is 25mm wider, 35mm taller for more
displacement and torque
> would not reveal increase in eccentricity. New
displacement is > 800cc/rotor.
>
> Aluminum end plates have plasma-sprayed wear
surface direct and indirect
> fuel injection.
>
> Torque gains come from longer e-dimension, more
displacement, direct
> injection.
>
> Would not confirm 300 hp power goal.
>
> All gas seals improved, smaller flame holes
adjacent to spark plugs.
>
> 16x engine ran for the first time this year. full
development will be at
> least 2 more years.
>
> Engine weight is reduced from 125kg [275 pounds]
to 100 kg [220 pounds].
>
> I hope you find this useful.
>
> Don Sherman
>
> We sure do Don, Thanks
>
> Paul Lamar
>
Using these number we can make same calculations as
follows:
25 mm wider means short axis from 180 to 205 mm
35 mm taller means long axis from 240 to 270 mm
This results in *E = 16.25* mm and in *R = 118.75*
mm,
The ratio R/E = 7.308 up from 7.0
The *width* would be 85 by linear upscale,
subtracting 5 mm we are back
down to *80* mm.
In fact 79.8 mm would be 800 cc, 80 mm width gives 2
cc more or 802 cc.
That is right on.
Regards
Rolf Pfeiffer
Thanks Rolf
Paul Lamar ...No rotor no motor.
Rolf
If you're adding 35mm to the height then it would be
275mm?
regards, Robert
Robert,
Yes you are right, 240 + 35 = 275, how did I miss that? Thanks for
catching it.
In this case, E would be 17.5 mm and R = 120 mm, round numbers, and much
more likely.
However, 80 mm width results in 873 cc per chamber.
The chamber volume supposed to be 800 cc, for that 73.5 is all that is
needed.
Perhaps they mean 5 mm (or close to it) less from the previous 80 mm ?
With E = 17.5 and R = 120 the R/E ratio becomes 6.857 down from 7.0
The ratio of stroke to piston area becomes higher which is what they
want, I suppose.
The RX7/8 were 0.33 S/D, above numbers would be 0.3764. A substantial
14% improvement in stroke.
That seems more likely.
NSU also went that direction with their latest developments before
folding.
We are lucky that Mazda has the financial means and carries on.
The last big NSU unit EA 871 was approximately like this: (calculating
back from its displacement and width. I had already left by then)
E = 17.28, R = 120.5, width = 69 (given), displacement = 746.6 cc (given).
This is very close to what Mazda seems to be doing now, if above numbers
are guessed correctly.
NSU had great hopes in that engine. It was used in a German fan-liner It
was the high point of the Wankel development at NSU.
Then the money run out. NSU was merged with AUDI and VW, the parent,
killed it all. Al further development was stopped.
Fan Trainer: http://www.der-wankelmotor.de/Flugzeuge/RFB/rfb.html#Fanliner
Paul,
You may add this link to my last message. It refers to the EA 871 engine.
http://www.der-wankelmotor.de/Motoren/Motoren_NSU_Audi/motoren_nsu_audi.html
Rolf
Rolf, Sounds to me that they must have had a good look at the results and
engineering of the EA 871.
George ( down under)
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