Paul,

Please forgive me, it's an age thing but I am not sure how to search for
answers or post questions with regard to the Rotary Compression Ratio, Could
you  post the request, I did have an e-mail from a gent that said that he
had seen a  reply within your link, but I did not see one.

I require the R' =R+a : e : width of Housing & Rotor Combustion  Pocket
volume and the stated CR

Bob

Perhaps AOL is not forwarding our messages to you.


Due to combustion chamber differences I am not sure what you mean by R',
a, R and e.

Is I am guessing. Is e the ecentric radius?

The depression volume varies with the year. A rotor I have
here in my office is 10 mm deep. Mean width is 48
mm and it is about 77 mm long. CR is roughly 9.6.
Housing width is 80 mm.

Did you download the "book"?

You can download Kenichi Yamamoto's book "Rotary Engine" from this
web site. It contains most of the dimensions on the Mazda rotary.

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

Here are a couple of excerpts.

Other info is scattered throughout the tech papers on our site.

I think you are not scrolling down and reading all of the message
as this was on here quite some time ago after you asked the question
in the first place. Please use this coordinate system as the standard.

Paul Lamar
------------------------------------------------------------------------
Hi Bob;

 Be wary of formulas errors in both the '71 and '81 editions of KY's
 Rotary Engine books.
 Here is an old email on the error in the volume formula.

 '81 Edition, page 14, Section 2.4.2, bottom right - formula 2.24
 V=volume
 e=eccentricity=15mm
 R=Generating circle radius= 105mm
 b=width of rotor housing= 80mm
 alpha= degrees eshaft rotation
 Vmin=minimum volume at TDC (long formula 2.25) =~ 56.5cc or
 in the case of a 9.4CR rotor 654/(9.4-1)= 77.9cc

 V = Vmin + ( 3 * root(3) / 3) * e * R * b ) * (1 - sin(2/3 * alpha +
 pi/6) )

 Formula makes more sense if you look at Figure 2.9 on page 15. Shows
 the chamber volume
 changes as a sine wave based on eshaft rotation compared to a piston
 engine.

 I just noticed the formula is different in the '71 edition.
 3 * root(3) * e * R * b =~ 654cc (swept volume) - the "/ 3" term
 appears to be incorrect.
 The "/ 2" in the '71 edition appears to be correct.

 Still need to work out the intake close timing angle. Not sure if the
 alpha value can be replaced with the
 degrees of eshaft rotation?

 Thanks
 Cary