Subject: Some questions as I get started on this project
From: paul lamar
Date: 10/1/2016, 4:14 PM
To: A10-Me-Earthlink



 Paul,

 1 - Is there a book or books that I can acquire that treats the
 mathematical development of the shapes of the housing and rotor
 specifically for Wankels ? - I'm thinking of programming my CNC
 milling equipment and rather than measure an existing engine would
 like to approach it from a mathematical point of view rather than
 physical measurements -

 2 - In particular, are there any specific fundamental equations
 available for the SACHS lawnmower, OMC snowmobile, and Mazda engines
 - I would like to be able to predict mathematically generated CNC
 paths and compare them to measurements of actual parts if possible

 3 - The aluminum of the OMC housing and other parts appears to be
 fairly soft, possibly the standard 356 casting alloy - I plan to use
 6061-T6 as David Mikesell has mentioned  - The OMC housing appears to
 have some sort of coating on the running surface that is much harder
 - Mentioned was Niksal (correct spelling ?) - Would like to know a
 source or sources for getting that done -

 4 - Will probably machine and grind new eccentric shafts - Glad now
 that I saved all of my precision machine tools when I closed my small
 tool & die shop - Anxious to again be making metal shavings -

 4 - Mention was made of new seals for the Mazda engines - Any sources
 for new seals for the OMC snowmobile engines ? - Too bad I didn't
 pursue this when OMC was located here in Galesburg, Illinois - I did
 some contract work for them and knew the CEO personally but he has
 passed away now and the factory where the castings were made is long
 gone - I should try to locate some of the engineers and manufacturing
 people who worked on the project and try to pick their brains -

 5 - Does anyone on this list have information on expected life of the
 OMC engines if they are properly cared for and lubricated ? - The
 ones I have look like they led fairly rough lives - I have located
 three complete running snowmobiles in upper Minnesota.  I will be
 going to see them run and perhaps buy them - Expected lifetimes would
 be helpful to know how long they might last -

 Sorry for the load of questions all at one time -

 Roland Friestad

Have you looked at the web site?

http://www.rotaryeng.net/books10.html

Book Reviews Rev. 11


             WANKEL TYPE ROTARY ENGINES

 The definitive book on the rotary is simply called "ROTARY ENGINE"
by Kenichi Yamamoto published by Toyo Kogyo Co. Ltd. (Mazda) in
1969. This is a highly technical book chronicling the development of
the wankel by Mazda. Kenichi is an engineer and has risen to  CEO of
Mazda.


 This book on the rotary is also  called "ROTARY ENGINE"
by Kenichi Yamamoto published by Sankaido Co. Ltd.
Second edition published in 1981. This is an updated version of
the first "ROTARY ENGINE" book. Confusing eh what? This book
has a much greater emphasis on emissions.

 Another technical book on the Wankel rotary engine is; "The Wankel
RC Engine Design and Performance" by R.F.Ansdale Published by A.S.
Barnes & Company Lib of Cong 69-18692

 The Wankel engine Design Development Application by Jan P. Norbye.
Chilton Book Company. ISBN 0-8019-5591-2 Published in 1971. A little
history and results of the Wankel engine development by NSU,
Mercedes, Mazda and others and some results of work by
Curtiss-Wright.  Also some history on all rotary engines. Not as
technical as I would like but not bad.

These books will be easier to find then the Toyo Kogyo book.


You can download the Yamamoto books from

http://www.rotaryeng.net/interesting.html

and then    http://foxed.ca/index.php?page=rx7manual


Paul Lamar

Roland,

The generation of the trochoide shape is not that complicated, machining and finishing for a smooth surface however is a bit more so.

The machines that NSU used at the time were copying machines where the shape was picked up from a master shape by a roller of same diameter as the finishing tool.

If you like you may contact me directly for some more talk on that. FWIW, Paul should give you my e-mail address.

Rolf Pfeiffer


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