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.


Just a side comment:
Mazda is truly a unique company.  The automotive manufacturing business is
intensely competitive with frequent and brutal calls for cost-cutting
whenever the quarterly numbers take a dip.  Mazda has continued to dedicate
engineering talent and development dollars to the Wankel over many decades
despite these pressures. Sure, they've made some money on the RX-7 and RX-8
line, but they surely could have made just as much by spending this money on
marketing econoboxes.  They (rightly) believe that the Wankel has certain
inherent advantages, and are continuing to develop it.  We're all
beneficiaries.

Mark Waldron

Mark

Yes Mazda has stuck with it but it would be accurate to say a small group of
guys within Mazda have persevered through all odds. Seiji Tashima, has taken
up the leadership from Yamamoto San as was shown in the Project X
documentary I translated.  Speaking of which, what ever happened to that CD?
I believe a lot of guys on this newsletter wanted to watch it.

I went to the Tokyo Motor show yesterday and have a few things to add to
what Don reported.

The engineer I spoke to confirmed that they have a target for 280Hp and have
considered turbo charging it. 280Hp is the legal limit a PRODUCTION car can
have in Japan.  Of course all makers are aware that after market tuners will
soon be jacking the engine up to well over that.

The 16X housings are 5mm narrower, and the new engine is lighter than the
Renesis but of course bigger in all dimensions. Need I say that 13B housings
won't fit:) ?  On the 'e' number the engineer was vague because he said the
engine was still in development and is still changing. He said a little less
than 20 now but I suspect he didn't want to give that info out and was
fibbing.

The engine and parts are in a plexiglass case so that pictures with a scale
in front didn't work. I did get some pictures comparing the 13B and 16X
rotors side by side for comparison as well a some monitor shots comparing
the 13B rotor path overlaid within the 16X.  I'm having some technical
difficulties getting these photos sent to you though.  I'll try again this
evening when my other half comes home.

There are now three oil injection points.  Again the engine on display is an
earlier test engine to see if two oil injection are better than one. WHY?
The larger rotor will be heavier of course and it appears the top rpm will
have to be limited to 8500rpm.  as the line speed and force on the seals
will be greater.

The 12 o'clock overhead direct injector is the primary injector and it is a
special order item from Nippon Denso. The 16X team has a goal to improve
fuel mileage by 10%  and at lower rpms this injector helps a lot. Secondary
is in the side port.  At what rpm the engine will have the less friction the
engineer couldn't say.

My conclusion: This engine is  an different and new animal and doesn't have
the advantage of 20 years of performance testing like the 13B based engines.
It will be at least two years but probably more if Mazda follows their
pattern of introducing new technology, before we see it in a production car.

Doug in Japan


The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2007 All world wide rights reserved.