Mailing List flyrotary@lancaironline.net Message #40459
From: George Lendich <lendich@optusnet.com.au>
Subject: Fw: [Bulk] 16x
Date: Thu, 22 Nov 2007 16:51:03 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>


Ed, Lynn and Bill +

This was posted to me privately and may help to clarify the specifications of the 16x. Some of the info are estimations by Rolf  Pfeiffer ex - NSU engineer.

Hello George
Nice to hear from you. Here is my assessment:

Also info supplied by Don Sherman as follows:-

I interviewed 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, and direct injection.

He would not confirm 300 hp power goal.
All the gas seals are improved,  with smaller flame holes adjacent to spark plugs.
The 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].

Assessment by Rolf Pfeiffer as follows:-

/Now, using above dimensions we get the following:

25 mm wider means the short axis goes from 180 to 205 mm.
35 mm taller means the long axis goes from 240 to 275 mm.

This results in E = 17.5 mm, and R = 120 mm.
The old dimensions were E = 15 mm and R = 105 (including the radius of 3 mm for the apex seals).
The ratio R/E is 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’s were 0.33 S/D, above numbers would be 0.3764, a substantial 14% improvement in ratio of stroke to equivalent piston diameter. A long stroke engine, so to speak.

I also had stated that:
NSU also went that direction with their latest developments before folding.
We are lucky that Mazda has the financial means and does carry 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, so the info is calculated.)
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 right.
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 did run out. NSU was merged with AUDI, and VW the parent, killed it all. All further development was stopped.

Fan Trainer: http://www.der-wankelmotor.de/Flugzeuge/RFB/rfb.html#Fanliner

Regards
Rolf


George Lendich wrote:
Rolf,
Could you give me your assessment of the new 16X eccentric. If I remember correctly you gave you assessment on Paul's site. There is discussion on another site and I would like to pass it on to interested parties.
Also if my memory serves me right, you mentioned a manufacturer was working on a similar size ( change in eccentric) and what company that was.
Am I wrong to believe it was the company you were working with at the time?
George Lendich


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